Proceedings Volume 7826

Sensors, Systems, and Next-Generation Satellites XIV

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Proceedings Volume 7826

Sensors, Systems, and Next-Generation Satellites XIV

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Volume Details

Date Published: 13 October 2010
Contents: 20 Sessions, 72 Papers, 0 Presentations
Conference: SPIE Remote Sensing 2010
Volume Number: 7826

Table of Contents

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Table of Contents

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  • Front Matter: Volume 7826
  • Japanese Missions I
  • Japanese Missions II
  • Japanese Missions III
  • European Missions I
  • European Missions II
  • European Missions III
  • US Missions I
  • US Missions II
  • SWOT Mission
  • Missions and Sensing I
  • Missions and Sensing II
  • FPA I
  • FPA II
  • FPA III
  • Joint Session: Airborne Remote Sensing: Programs and Data Sets
  • Calibration I
  • Calibration II
  • Global Earth Observation System of Systems
  • Poster Session
Front Matter: Volume 7826
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Front Matter: Volume 7826
This PDF file contains the front matter associated with SPIE Proceedings Volume 7826, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.
Japanese Missions I
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Overview of Japanese Earth observation programs
Five programs, i.e. TRMM, AMSR-E, ASTER, ALOS and GOSAT are going on in Japanese Earth Observation programs. ASTER has lost its short wave infrared channels, but other satellites/sensors are operating well, and TRMM operation will be continued at least up to 2012. ADEOS2 was failed, but AMSR-E on Aqua is operating. ALOS (Advanced Land Observing Satellite) was successfully launched on 24th Jan. 2006. ALOS carries three instruments, i.e., PRISM (Panchromatic Remote Sensing Instrument for Stereo Mapping), AVNIR-2 (Advanced Visible and Near Infrared Radiometer), and PALSAR (Phased Array L band Synthetic Aperture Radar). PRISM is a 3 line panchromatic push broom scanner with 2.5m IFOV. AVNIR-2 is a 4 channel multi spectral scanner with 10m IFOV. PALSAR is a full polarimetric active phased array L-band SAR. PALSAR has many observation modes including full polarimetric mode and scan SAR mode. GOSAT (Greenhouse Gas Observation Satellite) was successfully launched on 29, January, 2009. GOSAT carries 2 instruments, i.e. a green house gas sensor (TANSO-FTS) and a cloud/aerosol imager (TANSO-CAI). The main sensor is a Fourier transform spectrometer (FTS) and covers 0.76 to 15 μm region with 0.2 to 0.5 cm-1 resolution. SMILES (Super-conducting Millimeter wave Emission Spectrometer) was launched on September 2009 to ISS and started the observation, but stopped its operation on April 2010. After the unfortunate accident of ADEOS2, JAXA still have plans of Earth observation programs. Next generation satellites will be launched in 2011- 2014 timeframe. They are, GCOM-W and GCOM-C (ADEOS-2 follow on), and GPM (Global Precipitation Mission) core satellite. GPM is a joint project with NASA and will carry two instruments. JAXA will develop DPR (Dual frequency Precipitation Radar) which is a follow on of PR on TRMM. Another project is EarthCare. It is a joint project with ESA and JAXA is going to provide CPR (Cloud Profiling Radar). ALOS F/O satellites are divided into two satellites, i.e. SAR and optical satellites. The first one of ALOS F/O is called ALOS 2 and will carry L-band SAR, while second one is called ALOS3 and will carry optical sensors.
On orbit status of TANSO-FTS on GOSAT
To map the global column dry mole fractions of carbon dioxide (CO2) and methane (CH4), the Green house gases Observing SATellite (GOSAT) was launched on January 23, 2009. The Thermal And Near infrared Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS) and Cloud and Aerosol Imager (TANSO-CAI) are onboard on GOSAT to derive the precise amount of CO2 and CH4 in atmosphere measuring the solar light intensity reflected and scattered on the earth's surface and the thermal radiation. The first high spectral resolution Short Wave Infrared (SWIR) spectra by TANSO-FTS and the image by TANSO-CAI were acquired on February 7, 2009. TANSO has been continuously measuring CO2 and CH4 distributions in global every three days periods, and data distribution for public users was started from February 16, 2010. After the launch, the on-orbit characterization of performance, calibration, and health monitoring of TANSO has been continuously conducted with updating the Level-1 and -2 processing algorithm. During the over one-year operation period, a few anomalies such as instability of pointing mechanism, varying offset of pointing position, small wave-number shift and Zero Path Difference position change, were observed. The radiometric responses for FTS and CAI are also slightly changing. To minimize these effects in data using, quality flags were additionally included in product, response functions are updated and the regular operation procedure was slightly changed. In this presentation, the detail of on-orbit status of TANSO will be reported.
Calibration of operational GOSAT Level 1 products
Kei Shiomi, Tomoko Kina, Shuji Kawakami, et al.
Greenhouse gases Observing SATellite (GOSAT) is a Japanese mission to observe greenhouse gases, such as CO2 and CH4, from space with a Fourier transform spectrometer and a push broom imager. The GOSAT was launched on January 23, 2009. The GOSAT is operated normally and acquired the observation data over 1.5 year from April 2009 of initial calibration and validation phase. The Level 1 products were released to public from October 2009, the Level 2 from February 2010. The Level 1 products are updated and evaluated the calibration accuracies in the operational observation phase.
Japanese Missions II
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GOSAT higher level product status 1.5 year after the launch
Hiroshi Watanabe, Akira Yuki, Kenji Hayashi, et al.
After the 1.5 year operation of GOSAT (Greenhouse gases Observing SATellite), NIES GOSAT DHF (GOSAT Data Handling Facility of National Institute for Environmental Studies) has been producing CAI Level 1B and 1B+, FTS/CAI Level 2, and FTS/CAI Level 3 products, receiving FTS Level 1A/1B and CAI Level 1A data from JAXA (FTS: Fourier Transform Spectrometer; CAI: Cloud and Aerosol Imager; JAXA: Japan Aerospace Exploration Agency). In addition to the higher level data processing, GOSAT DHF has the following additional roles: 1) Data archive and distribution, and 2) Observational request collection from users and their submission to JAXA. After calibration and preliminary validation, the processed data are distributed to RA users at the first stage (RA users: researchers engaging in Research Announcement). The processed data are validated and then they are distributed to General Users (GU). All the distribution is carried out through the GOSAT User Interface Gateway (GUIG). As of August 2010, the total number of user registration exceeds 900, and a large number of products are distributed both to the RA users and GU. At this moment, validation indicates that the FTS SWIR L2 CO2 and CH4 data show slightly lower values than validation results. Therefore, further improvement of the algorithm is planned as a next version of the FTS L2 products. FTS TIR data processing is still on the way.
Status of GCOM-W1 development and expected meteorological applications
Daisaku Uesawa, Keiji Imaoka, Misako Kachi, et al.
The Global Change Observation Mission (GCOM) consists of two polar orbiting satellite observing systems, GCOM-W (Water) and GCOM-C (Climate), and three generations to achieve global and long-term monitoring of the Earth. GCOM-W1 is the first satellite of the GCOM-W series and scheduled to be launched in Japanese fiscal year 2011. The mission instrument will be the Advanced Microwave Scanning Radiometer-2 (AMSR2), which is the successor instrument of AMSR on ADEOS-II and AMSR-E on EOS Aqua platform. Development of the GCOM-W1 system progresses favorably. The mechanical and thermal tests using the GCOM-W1 structural and thermal model were successfully completed. The GCOM-W1 and AMSR2 proto-flight models are under their proto-flight testing. In the middle of 2010, AMSR2 will be delivered to satellite system prior to the system proto-flight test of GCOM-W1. Retrieval algorithms are being developed by collaborating with principal investigators. Algorithm comparisons or integrations are now underway for several algorithms to find best available algorithms for post-launch processing. Also, maintaining and extending the validation sites such as the Mongolian Plateau site for soil moisture is being implemented. In addition to the long-term climate variability monitoring, meteorological applications will be the most important operational utilization of AMSR2 data. Currently, AMSR-E data are being used for numerical prediction through data assimilation at several meteorological agencies. Also, retrieved geophysical parameters such as sea surface temperature are being used for diagnostics of the weather and ocean variations.
Engineering model activity of the Second-generation Global Imager(SGLI)
The Second-generation Global Imager (SGLI) on the Global Change Observation Mission (GCOM) is a multi-band optical imaging radiometer in the wavelength range from near-UV to thermal infrared. SGLI will provide high accuracy measurements of Ocean, Atmosphere, Land and Cryosphere. SGLI project is under Engineering Model (EM) phase to design and verify the overall sensor system prior to the Proto Flight Model (PFM) manufacturing. Based on previous Bread Board Model (BBM) results[1], the Scanning Radiometer Unit (SRU) and the Electronical Unit (ELU) are under development. The total sensor system verification is planned including not only optical test but also environmental test, such as rocket vibration environment and thermal vacuum environment, so on. This paper describes the current status of the SGLI instrument development.
Development status of Japanese space-borne cloud profiling radar for EarthCARE mission
The EarthCARE mission has been jointly proposed by European and Japanese scientists with the mission objective of improving the understanding of cloud-aerosol-radiation interactions so as to include them correctly and reliably in climate and numerical weather prediction models. This EarthCARE mission has been defined as an international cooperative spacecraft mission between European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA) for the planned launch year of 2013th. The EarthCARE spacecraft equips four instruments, such as a cloud profiling radar (CPR), an atmospheric backscatter lidar (ATLID), a multi-spectral imager (MSI) and a broadband radiometer (BBR) to perform very accurate synergy observation to observe cloud and aerosol vertical profiles and simultaneous radiative flux at the top of atmosphere. In this cooperation, JAXA is responsible for development of the CPR which will be the first space-borne W-band radar with Doppler measurement capability. JAXA has developed this Doppler radar for several years with Japanese National Institute of Information and Communications Technology (NICT). The last year, preliminary design was finished and then fabrication and testing have been started. This presentation shows the summary of the CPR preliminary design and reports the test status of the CPR engineering model testing.
Japanese Missions III
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Status of development of the GPM Dual-frequency Precipitation Radar (DPR), algorithm development, and ground validation activities
Misako Kachi, Takeshi Miura, Riko Oki, et al.
In July 2009, NASA and JAXA signed implementation phase Memorandum of Understanding to be the central body for creating the Global Precipitation Measurement (GPM) partnership. The Global Precipitation Measurement (GPM) started as an international project and a follow-on mission of the Tropical Rainfall Measuring Mission (TRMM) project to achieve more accurate and frequent precipitation observations than it. A Dual-frequency Precipitation Radar (DPR) on board the GPM core satellite is being developed steadily by JAXA and NICT, and consists of Ku-band (13.6GHz) and Ka-band (35.5GHz) precipitation radars to measure light rainfall and snowfall as well as moderate-to-heavy rainfall. The GPM core observatory scheduled to be launched by Japanese H-IIA rocket in summer of 2013. In January 2010, JAXA has selected the principal investigators by the 6th Precipitation Measuring Mission (PMM) Research Announcement, especially focusing on the GPM algorithm development and pre-launch validation. The GPM standard algorithm will be developed by U.S.-Japan Joint GPM Algorithm Team, and Japanese members will play central role in developing DPR and DPR/GMI combined algorithms. Pre-launch validation aims to contribute to the development and improvement of algorithms, through validating parameter errors, which are involved in satellite-based precipitation retrieval algorithms, such as attenuation by precipitation particles, raindrop size distribution, and drop velocity and density of snowfall. JAXA will put two new field-portable Ka-band Ground Validation radars in 2009-2010 to achieve this target. The new science team will be organized in April 2010, and team members expected to make effective interactions between algorithm development and pre-launch validation activities.
Development status of Japanese Advanced Land Observing Satellite-2
Yoshihisa Arikawa, Yuji Osawa, Yasushi Hatooka, et al.
The Advanced Land Observing Satellite-2 (ALOS-2) is a follow-on mission from ALOS "Daichi". The state-of-the-art L-band Synthetic Aperture Radar (SAR) aboard ALOS-2 will, in response to society's needs, have enhanced performance compared to ALOS/PALSAR. ALOS-2 will have a spotlight mode (1 and 3 m) and a high-resolution mode (3 to 10 m), while PALSAR has 10m resolution. The Preliminary Design was completed in March, 2010. Phase C/D has been started and the Engineering Models are currently under development. This paper describes the current development status of ALOS-2.
Current status of Advanced Land Observing Satellite-3 (ALOS-3)
The Advanced Land Observing Satellite (ALOS) "Daichi," launched in January 2006, has been operating successfully on orbit for four and a half years. In that time it has delivered a very large number of high-resolution images and has contributed to making basic maps, updating maps, gathering information on natural resources, and disaster management support in a variety of fields. The Japan Aerospace Exploration Agency (JAXA) has been planning a satellite system for the ALOS follow-on program. The ALOS follow-on program consists of two satellites: one is a radar satellite called ALOS-2, the other is an optical satellite called ALOS-3. ALOS-3 carries an optical imager with more enhanced capabilities than those of the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) aboard ALOS. ALOS-3 will produce a precise basic map with its systematic observation to be used in the Geographical Information System (GIS). ALOS-3 will also promptly provide precise postdisaster images to detect damaged areas through emergency observations when disasters occur. JAXA has been defining system requirements for the spacecraft and the mission instrument of ALOS-3, as well as conducting the conceptual design. This paper introduces the latest design, the mission concept, and the current status of ALOS-3.
Recent results from the superconducting submillimeter-wave limb-emission sounder (SMILES) onboard ISS/JEM
Masato Shiotani, Masahiro Takayanagi, Makoto Suzuki, et al.
The Superconducting submillimeter-wave limb-emission sounder (SMILES) employs superconducting detectors mechanically cooled down to ~4K, and it is extremely sensitive (Tsys < 400K), for the weak emission from trace species of stratosphere and mesosphere, such as O3, HCl, HNO3, ClO, HO2, and BrO. SMILES was launched onboard HTV spacecraft by using H-IIB launcher and started atmospheric observation in autumn of 2009. Using 2 bands among 3 bands in the 625 and 650 GHz submillimeter region, SMILES has been observing precise spectra with ~1K noise. Level- 2 (L2) data processing is on going at ISAS/JAXA in semi-real time basis. O3, HCl, HNO3 and ClO have strong emission signal in the SMILES frequency coverage and we already found that SMILES L2 data is comparable or even better than the existing best satellite observation of the atmosphere. HO2 and BrO have been retrieved with single scan data successfully and the results are under verification. Since SMILES observation is much better than any previous observation, validation of SMILES L2 data will be challenging. This paper describes L2 processing at ISAS/JAXA and early results of SMILES.
European Missions I
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Aspects of the EarthCARE satellite and its payload
EarthCARE is ESA's Earth Clouds Aerosols and Radiation Explorer and is a joint mission in collaboration with JAXA. The satellite will carry a suite of instruments which operate in synergy to provide simultaneous observations of clouds and aerosols and will lead to improved understanding and modelling of these factors as well as their role in climatology. Development of the four instrument payload, consisting of an Atmospheric Lidar (ATLID), a Cloud Profiling Radar (CPR), a Multi Spectral Imager (MSI) and a Broad Band Radiometer (BBR) has been continuing for some time now and all instruments have progressed beyond the preliminary design stage. The paper will describe the mission, the satellite and in particular the principles, performance and design evolution of the payload.
The EarthCARE multispectral imager thermal infrared optical unit detection system design
The EarthCARE satellite mission objective is the observation of clouds and aerosols from low Earth orbit. The key spatial context providing instrument within the payload suite of 4 instruments is the Multi-Spectral Imager (MSI).The MSI will take data at 500m ground sample distance (GSD) over a swath width of 150 km via pushbroom imaging. One part of the MSI instrument will be a thermal IR optical unit (TIROU). We describe the design of the focal plane array for the TIROU, its time-delay and integration readout scheme and present results derived from its associated simulator.
European Missions II
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Design and development of the Sentinel-2 Multi Spectral Instrument and satellite system
Vincent Chorvalli, Vincent Cazaubiel, Stefan Bursch, et al.
2A and Sentinel-2B satellites currently under development will ensure systematic global acquisition of all land and coastal waters in the visible and short-wave infrared spectral domain with a 5 day revisit time at the equator. The Multi Spectral Instrument is a push-broom imager providing imagery in 13 spectral channels with spatial resolutions ranging from 10 m to 60 m and a swath width of 290 Km, larger than SPOT and Landsat. The instrument features a full field of view calibration device, a silicon carbide Three Mirror Anastigmat telescope with mirror dimensions up to 600 mm, specific filter stripe assemblies, newly developed Si-CMOS and HgCDTe detectors and a low noise wavelet compression video electronics. The 1.4 Tbits/s raw image date rate is reduced down to 490 Mbits/s at the output of the instrument to cope with the overall system transmission capability. The Sentinel-2 program has entered in the CD phase in 2009. Launch of Sentinel-2A satellite is scheduled for 2013.
Status of the Sea & Land Surface Temperature Radiometer (SLSTR) for the Sentinel 3 GMES Mission
Peter Coppo, Massimo Cosi, Wolfgang Engel, et al.
The Sea & Land Surface Temperature Radiometer (SLSTR) is a high accuracy infrared radiometer selected as optical payload for the Sentinel 3 component of the GMES mission, to provide climatological data continuity respect to the previous ERS and ESA Envisat missions, that embarked respectively the ATSR, ATSR-2 and AATSR payloads. The instrument design follows the dual view concept of the ATSR series with some notable improvements. An increased swath width in both nadir and oblique views (1400 and 740 km) provides measurements at global coverage of Sea and Land Surface Temperature (SST/LST) with daily revisit times, which is useful for climate and meteorology (1 Km spatial resolution). Improved day-time cloud screening and other atmospheric products will be possible from the increased spatial resolution (0.5 Km) of the VIS and SWIR channels and additional SWIR channels at 1.375μm and 2.25μm. Two additional channels using dedicated detector and electronics elements are also included for high temperature events monitoring (1 km spatial resolution). The two Earth viewing swaths are generated using two telescopes and scan mirrors that are optically combined by means of a switching mirror at the entrance of a common Focal Plane Assembly. The eleven spectral channels (3 VIS, 3 SWIR, 2 MWIR, 3 TIR) are split within the FPA using a series of dichroics. The SWIR, MWIR and TIR optics/detectors are cooled down to 80 K with an active cryocooler, while the VIS detectors work at a stabilised uncooled temperature. The paper highlights the technical and programmatic status of the project, which is now in phase C.
Design and development of the Sentinel-3 Microwave Radiometer
Marc Bergadà, Patricia Brotons, Yolanda Camacho, et al.
The Sentinel-3 (S-3) Microwave Radiometer (MWR) is being developed by EADS CASA Espacio (ECE) under contract with Thales Alenia Space France (TAS-F) and the European Space Agency (ESA). This instrument, along with a radar altimeter and a precise orbit determination package, is part of a topographic mission in the frame of the Global Monitoring for Environment and Security (GMES) programme. The MWR will determine the amount of humidity in the atmosphere in order to correct for the wet tropospheric path delay of the altimeter data by means of brightness temperature measurements at 23.8 GHz and 36.5 GHz. This paper describes the design and development plan for the MWR instrument.
European Missions III
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Feasibility studies for the follow-on EUMETSAT polar system
S. Banfi, P. Schlüssel, D. Diebel, et al.
replace the current satellite system in the 2020 timeframe and contribute to the Joint Polar System to be set up with NOAA. Through consultation with users and application experts, requirements have been defined for a range of candidate missions mainly in support of operational meteorology and climate monitoring. A number of on-board instruments, satellite platforms and ground support infrastructure are under study in coordination with ESA, NOAA, DLR and CNES. The satellites will fly in a sun synchronous, low earth orbit at 817 km altitude and 09:30 descending equatorial crossing time, providing observations with global coverage every 12 to 24 hours depending on instrument. The instruments exploit a range of techniques including multi spectral imaging, atmospheric sounding in the optical and microwave spectral domains, radio occultation sounding, scatterometry and microwave imaging. The raw instrument data will be broadcast directly by the satellites, as well as being stored on board for their transmission, in sets spanning up to a full orbit, to polar ground stations. These data will be collected at EUMETSAT facilities and processed to obtain calibrated and geo-located measurements, and records of well defined geophysical variables. The data will be distributed to the users in near real time and archived together with the data of other EUMETSAT satellite systems, making available long term records also suitable for climate monitoring. Feasibility studies for the space and ground systems will be done until early 2012 with the main objective to select the baseline configuration for preliminary definition, development and operation programmes to be proposed and coordinated within the involved organisations.
METimage: a multispectral imaging radiometer for the EUMETSAT Polar System follow-on satellite mission
F. Schmülling, I. Zerfowski, A. Pillukat, et al.
The evolving needs of the meteorological community concerning the EUMETSAT Polar System follow-on satellite mission (Post-EPS) require the development of a high-performance multi-spectral imaging radiometer, the so-called Visible-Infrared Imager (VII). Recognizing these needs, Jena Optronik GmbH proposed an innovative instrument concept, METimage. METimage is the candidate instrument to fulfill the VII mission on Post-EPS. Core item of the METimage instrument is a rotating telescope scanner covering the large swath width of about 2800 km, which is needed for a global coverage by a polar platform. The de-rotated image facilitates in-field spectral channel separation, which allows tailoring individual channel GSD (ground sampling distance) and features like TDI (time delay and integration). State-of-the-art detector arrays and read-out electronics will be employed. The reflecting telescope design is able to support demanding requirements on image quality and ground resolution. The chosen instrument concept covers a spectral range from 443 nm to 13.345 μm and provides 20 to 22 spectral channels. The ground sampling distance is 500 m and 250 m for selected high-resolution channels from low Earth orbit. The METimage instrument development is currently in phase B and has undergone its System Requirements Review in summer 2010.
Megha-Tropiques satellite mission: sensors performances
Nadia Karouche, Garuda Raju
MEGHA-TROPIQUES is an CNES-ISRO collaborative satellite mission designed to study processes related to large tropical convective systems and their life cycle, and to provide key elements related to atmospheric energy and water budget at various time and space scales. The satellite will perform high repetitive measurements using a low inclined (20°) orbit, and will carry 4 instruments : • MADRAS Instrument: A conical scanning microwave imager designed to estimate precipitations and clouds properties. • SAPHIR Instrument: A microwave sensor used to retrieve vertical humidity profiles. • SCARAB Instrument: An wide band optical radiometer used to retrieve Earth Radiation budget parameters. • GPS-ROS instrument: The sensor will provide temperature and humidity profiles of the Earth's atmosphere The MEGHA-TROPIQUES satellite is planned to be launched in 2011 by the Indian PSLV launcher. This paper presents the mission, the satellite definition and the measured performances of the sensors.
PROBA-V, a vegetation satellite
Guillaume Huby, Richard P. Kleihorst, Karim Mellab, et al.
The SPOT/VEGETATION mission is going to its end and ESA, CNES and industry investigated the possibility of proposing a "VEGETATION like instrument" onboard a satellite based on the PROBA concept and design. The studies have demonstrated that due to the recent advances in miniaturization technology, this objective can be reached without losing compromising quality with respect to the SPOT/VEGETATION Instrument. The resulting PROBA-V mission aims at ensuring continuity to SPOT/VEGETATION products, providing daily images at low resolution over the world. The instrument consists of Three-Mirror-Anastigmatic (TMA) cameras (to cover the 2250 km swath width), each equipped with blue, red, near-infrared and short-wave infrared detectors. As a passive thermal control method is used, a thermo-elastic model is used in the user segment on-ground to correct for the geometric and radiometric properties. While for this ESA project, Verhaert Space is responsible as prime for the instrument, VITO acts as prime for setting up and running the user segment, including geometric and radiometric calibration. Special attention is placed to dealing with the different noise characteristics, viewing angles and ground sampling distance of the detectors. The Ground Segment and the User Segment will exploit the satellite capabilities, receiving, processing, archiving and disseminating Primary products, for advanced users and corrected Synthesis for the common Vegetation end users at 1000m and 250m spatial resolution. However, in the end a more agile, area and power efficient satellite system is designed that gives equal and in many parameters better performance than the current SPOT/VEGETATION Instruments.
US Missions I
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NASA's Earth science flight program status
NASA's strategic goal to "advance scientific understanding of the changing Earth system to meet societal needs" continues the agency's legacy of expanding human knowledge of the Earth through space activities, as mandated by the National Aeronautics and Space Act of 1958. Over the past 50 years, NASA has been the world leader in developing space-based Earth observing systems and capabilities that have fundamentally changed our view of our planet and have defined Earth system science. The U.S. National Research Council report "Earth Observations from Space: The First 50 Years of Scientific Achievements" published in 2008 by the National Academy of Sciences articulates those key achievements and the evolution of the space observing capabilities, looking forward to growing potential to address Earth science questions and enable an abundance of practical applications. NASA's Earth science program is an end-to-end one that encompasses the development of observational techniques and the instrument technology needed to implement them. This includes laboratory testing and demonstration from surface, airborne, or space-based platforms; research to increase basic process knowledge; incorporation of results into complex computational models to more fully characterize the present state and future evolution of the Earth system; and development of partnerships with national and international organizations that can use the generated information in environmental forecasting and in policy, business, and management decisions. Currently, NASA's Earth Science Division (ESD) has 14 operating Earth science space missions with 6 in development and 18 under study or in technology risk reduction. Two Tier 2 Decadal Survey climate-focused missions, Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) and Surface Water and Ocean Topography (SWOT), have been identified in conjunction with the U.S. Global Change Research Program and initiated for launch in the 2019-2020 timeframe. NASA will begin refurbishment of the SAGE III atmospheric chemistry instrument to be hosted by the International Space Station (ISS) as early as 2013 and will initiate a Gravity Recovery and Climate Experiment (GRACE) Follow-on mission for launch in 2016.
Accurate monitoring of terrestrial aerosols and total solar irradiance: the NASA Glory mission
Brian Cairns, Michael Mishchenko, Hal Maring, et al.
Current uncertainties in the total solar irradiance (TSI) and aerosol radiative forcings of climate are so large that they limit quantitative evaluation of climate models against global temperature change. Reducing these uncertainties is the objective of the NASA Glory mission scheduled for launch in November 2010 as part of the NASA A-Train. Glory is intended to meet the following scientific objectives: Improve the quantification of solar variability by continuing the uninterrupted 32-year satellite measurement record of TSI, facilitate the quantification of the aerosol direct and indirect forcings of climate, and provide better aerosol representations for use by other operational satellite instruments.
Aquarius/SAC-D: an international remote sensing satellite mission measuring sea surface salinity
Amit Sen, Daniel Caruso, David Durham, et al.
The Aquarius/SAC-D mission is the fourth earth-observation satellite jointly developed by NASA and CONAE. This international remote sensing mission (with contributions from USA, Argentina, Brazil, Italy, France and Canada) has the primary objective to investigate the links between global water cycle, ocean circulation and climate by measuring Sea Surface Salinity (SSS). The mission is undergoing Observatory level testing and being prepared to be launched from USA. This paper will present the mission, instruments, testing and performance status of the Observatory and show the final preparation towards launch.
The Orbiting Carbon Observatory instrument: performance of the OCO instrument and plans for the OCO-2 instrument
Randy Pollock, Robert E. Haring, James R. Holden, et al.
NASA's Orbiting Carbon Observatory (OCO) was designed to make measurements of carbon dioxide concentrations from space with the precision and accuracy required to identify sources and sinks on regions scales (~1,000 km). Unfortunately, OCO was lost due to a failure of the launch vehicle. Since then, work has started on OCO-2, planned for launch in early 2013. This paper will document the OCO instrument performance and discuss the changes planned for the OCO-2 instrument.
Global Precipitation Measurement (GPM) implementation
Steven P. Neeck, Ramesh K. Kakar, Ardeshir A. Azarbarzin, et al.
The Global Precipitation Measurement (GPM) mission will provide enhanced space-based precipitation measurements with sufficient coverage, spatial resolution, temporal sampling, retrieval accuracy, and microphysical information to advance the understanding of Earth's water and energy cycle and to improve predictions of its climate, weather, and hydrometeorological processes. Such improvements will in turn improve decision support systems in broad societal applications (e.g. water resource management, agriculture, transportation, etc). GPM is a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA), building upon their highly successful partnership on the Tropical Rainfall Measuring Mission (TRMM). The GPM architecture consists of NASA satellites operating in partnership with other earth-observing satellites and instruments to produce global precipitation science data. The current generation of multi-satellite global precipitation products based on microwave/infrared sensors from uncoordinated satellite missions has for its anchor the TRMM precipitation radar and the TRMM Microwave Imager measurements over the tropics and subtropics (+/- 35 degrees latitude), with a mean sampling time of approximately 17 hours. The GPM mission will deploy a spaceborne Core Observatory as a reference standard to unify a space constellation of research and operational microwave sensors aimed at providing uniformly calibrated precipitation measurements globally every 2-4 hours. The Core Observatory measurements will provide, for the first time, quantitative information on precipitation particle size distribution needed for improving the accuracy of precipitation estimates by microwave radiometers and radars. In addition, the GPM will also include a second microwave radiometer and a Tracking and Data Relay Satellite (TDRS) communications subsystem for near real time data relay for a future partner-provided constellation satellite. This second GPM Microwave Imager (GMI) instrument, flown in a low-inclination orbit, combined with the Core Observatory will provide an improvement over TRMM in both global coverage and sampling rate (+/- 65 degrees, 10 hour mean sampling time). GPM is well into its final design and fabrication (Phase C) with planned launches in 2013 and 2014.
US Missions II
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The Jason-3 Mission: completing the transition of ocean altimetry from research to operations
Parag Vaze, Steven Neeck, Walid Bannoura, et al.
The Jason-3 mission is planned as a follow-on mission to the Ocean Surface Topography Mission/Jason-2, to continue the core satellite altimetry measurements for physical oceanography. In addition, a key long-term vision of the founders of this measurement will come to reality: the transitioning from research to operational applications of this valuable measurement. Jason-3 builds upon the heritage of foundational and transitional missions such as SEASAT (1978), GEOSAT (1985), TOPEX/Poseidon (T/P, 1992), Jason-1 (2001) and OSTM/Jason-2 (2008), which have led to the understanding and development of a wide range of oceanographic applications of satellite altimetry. With the successful development and operation of the TOPEX/Poseidon and Jason-1 missions, the Franco-American cooperation in ocean altimetry has grown with a steady vision of expanding this measurement towards operational applications. As such, the T/P and Jason-1 missions were developed by NASA and CNES, and subsequently NOAA and EUMETSAT have taken on key partnership roles by providing mission operations services for the OSTM/Jason-2 project. For Jason-3, NOAA and EUMETSAT are the lead agencies with CNES and NASA as key partners providing mission development support. With a planned project start in early 2010 and a launch target of mid-2013, Jason-3 is planned as a recurring mission from OSTM/Jason-2 to minimize satellite development risk as well as to ensure the continuity of measurements after OSTM/Jason-2. The Jason-3 satellite is planned to operate at the same 1336 km, 66 deg. inclination reference orbit with essentially the same on-board instrumentation as OSTM/Jason-2. The instrument suite will consist of a dual-frequency Nadir Altimeter, a Microwave Radiometer, and three Precision Orbit Determination instruments (Global Positioning System - GPS, Doppler Orbitography and Radio-positioning Integrated by Satellite -DORIS, and Laser Retroreflector Array - LRA). Fulfilling the goals of moving satellite altimetry onto routine operations will require a close cooperation and coordination of international, multi-agency mission managers, designers, engineers, scientists and operational systems developers. This paper presents the Jason-3 mission formulation and development plans, and highlights the key aspects of making this multidimensional project move towards reality.
Ice, Clouds and Land Elevation (ICESat-2) Mission
Douglas D. McLennan
In recent years, the melting ice shelf and global warming headlines continue to remain prominent in the media circuits. The public and our science community want to know why and what can be done accurately to evaluate the changes and respond accordingly to the threat. The National Aeronautics and Space Administration (NASA) announced ICESat-2 as the next environmental mission. The NASA Goddard Space Flight Center (GSFC) in Greenbelt, Maryland, is responsible for the implementation of the ICESat-2 Mission.
CLARREO: cornerstone of the climate observing system measuring decadal change through accurate emitted infrared and reflected solar spectra and radio occultation
Stephen P. Sandford, David F. Young, James M. Corliss, et al.
The CLARREO mission addresses the need to provide accurate, broadly acknowledged climate records that can be used to validate long-term climate projections that become the foundation for informed decisions on mitigation and adaptation policies. The CLARREO mission accomplishes this critical objective through rigorous SI traceable decadal change observations that will reduce the key uncertainties in current climate model projections. These same uncertainties also lead to uncertainty in attribution of climate change to anthropogenic forcing. CLARREO will make highly accurate and SI-traceable global, decadal change observations sensitive to the most critical, but least understood climate forcing, responses, and feedbacks. The CLARREO breakthrough is to achieve the required levels of accuracy and traceability to SI standards for a set of observations sensitive to a wide range of key decadal change variables. The required accuracy levels are determined so that climate trend signals can be detected against a background of naturally occurring variability. The accuracy for decadal change traceability to SI standards includes uncertainties associated with instrument calibration, satellite orbit sampling, and analysis methods. Unlike most space missions, the CLARREO requirements are driven not by the instantaneous accuracy of the measurements, but by accuracy in the large time/space scale averages that are necessary to understand global, decadal climate changes.
SWOT Mission
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The Surface Water and Ocean Topography Mission: a mission concept to study the world's oceans and fresh water
Parag Vaze, Vincent Albuys, Daniel Esteban-Fernandez, et al.
The Surface Water and Ocean Topography (SWOT) is a planned satellite mission to study the world's oceans and terrestrial surface water bodies. The SWOT mission concept has been proposed jointly by the global Hydrology and Oceanography science communities to make the first global survey of the Earth's surface water, observe the fine details of the ocean's surface topography, and measure how water bodies change over time. SWOT was one of 15 missions listed in the 2007 National Research Council's Decadal Survey for Earth science as a mission that NASA should implement in the incoming decade. This mission concept builds upon the heritage of prior missions and technologies such as Topex/Poseidon, Jason-1/ 2, the Shuttle Radar Topography Mission (SRTM), and the initial development of the Wide Swatch Ocean Altimeter intended for the Ocean Surface Topography Mission/Jason-2. The key measurement capability for SWOT is provided by a Ka-band synthetic aperture radar interferometer (KaRIn). With an orbit altitude of 970 km, the KaRIn instrument provides a high-resolution swath width of 120 km enabling global coverage (~90%) of the world's ocean's and fresh water bodies. The KaRIn measurement is being designed to provide a spatial resolution of 1 km for the oceans (after on-board processing), and 100 m for land water, both at centimetric accuracy. An additional instrument suite similar to the Jason series will complement KaRIn: a Ku-band nadir altimeter, a Microwave Radiometer and Precision Orbit Determination (POD) systems. To enable this challenging measurement performance, the SWOT mission concept is designed to overcome several challenges, such as very high raw data rate (320 Mbps), large on-board data volumes, high power demand, stringent pointing and stability requirements, and ground data processing systems, to produce meaningful science data products to our user community. The SWOT mission concept is being developed as a cooperative effort between NASA and CNES. This paper presents the initial end-to-end mission concept as well as the current plans to develop and implement this challenging mission in the future.
The Surface Water and Ocean Topography Mission (SWOT): the Ka-band Radar Interferometer (KaRIn) for water level measurements at all scales
Ernesto Rodriguez, Daniel Esteban-Fernandez
The Surface Water and Ocean Topography (SWOT) mission will study ocean mesoscale and submesoscale phenomena and provide an inventory of storage change and discharge for fresh water bodies and rivers. In this paper, we examine the combination of measurements that will be used by SWOT to achieve a globally consistent data set. We introduce a new channel in the SWOT measurement that combines data transmitted by the interferometer antennas and received by the radiometer antenna allows the closing of the SWOT nadir coverage gap. This new mode also allows for improved calibration between the nadir altimeter and the interferometer, resulting in consistent range measurements. Consistency in the phase measurements is achieved using a mixture of cross-over calibration combined with optimal estimation of system error drift.
The Surface Water and Ocean Topography Mission: centimetric spaceborne radar interferometry
D. Esteban-Fernandez, Ernesto Rodriguez, Lee-Lueng Fu, et al.
Over the last two decades, several nadir profiling radar altimeters have provided our first global look at the ocean basinscale circulation and the ocean mesoscale at wavelengths longer than 100 km. Due to sampling limitations, nadir altimetry is unable to resolve the small wavelength ocean mesoscale and sub-mesoscale that are responsible for the vertical mixing of ocean heat and gases and the dissipation of kinetic energy from large to small scales. The Surface Water and Ocean Topography (SWOT) mission being considered by NASA has as one of its main goals the measurement of ocean topography with kilometer-scale spatial resolution and centimeter scale accuracy. In this paper, we provide an overview of all error sources that contribute to the SWOT mission for the ocean. This paper is a sequel to an earlier paper describing the SWOT mission, the science and its payload.
KaRIn on SWOT: modeling and simulation of near-nadir Ka-band interferometric SAR images
Roger Fjørtoft, Fifamè Koudogbo, Javier Duro, et al.
The principal instrument of the wide-swath altimetry mission SWOT is KaRIn, a Ka-band interferometric SAR system operating on near-nadir swaths on both sides of the satellite track. Due to the short wavelength and particular observation geometry, there are very limited reports on the backscattering from natural surfaces. Simulators that cover both radiometric and geometric aspects are therefore developed in the framework of the CNES phase 0 and A studies of SWOT. This article presents the modeling and simulation approaches that have been adopted, and shows some preliminary simulation results.
A virtual mission to estimate discharge using assimilation of high-resolution simulated SWOT Data: initial results over the Ohio river
Delwyn Moller, Kostantinos Andreadis, Ernesto Rodriguez, et al.
In this paper we present a framework for a virtual mission (VM) that 1) models the basin-wide physical and hydraulic processes of a chosen study region, namely the Ohio river basin, 2) samples those processes with a high fidelity SWOT simulation to deliver realistic high-resolution temporally subsampled, spatially dense interferograms, 3) reconstructs the water surface elevation from the synthetic interferometric measurement. This is part of an ongoing effort where the elevation measurements, as during the SWOT mission, will be integrated into a data assimilation framework to estimate discharge. We present results from the key elements of the VM Ohio basin configuration including the study region extent and hydrodynamics model setup. Furthermore, an example of georeferenced reconstructed heights derived from the SWOT instrument simulator over the Ohio modeled region is given. These results illustrate the effects of random (thermal and fading/speckle) noise of the height estimates as well as explicitly evaluating the effects of topographic layover. In the near future the hydrodynamic modeling and synthetic SWOT acquisitions over the region will be run for several "virtual" months to provide data to support the discharge estimation algorithm development in preparation for SWOT.
Missions and Sensing I
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Technological evolutions on the FTS instrument for follow-on missions to SCISAT Atmospheric Chemistry Experiment
Jacques Giroux, Louis Moreau, Guillaume Girard, et al.
The Canadian satellite SCISAT-1 developed for the Canadian Space Agency in the context of the ACE mission (Atmospheric Chemistry Experiment) was launched in August 2003. The mission has been a tremendous technical and scientific success. The main instrument of the ACE mission is a high-resolution Fourier Transform Spectrometer (FTS) designed and built by ABB Bomem. Several new missions are currently considered as follow-on to the ACE mission to ensure continuity of the extensive high-quality data set of the Earth's atmosphere that was started with the ACE mission, but also possibly to bring new improvements and enhance the utilization of these data. A solar-occultation FTS based on the optical design for ACE-FTS, has been selected for a planetary exploration mission to measure the atmospheric composition of Mars that will launch in 2016. An overview of these different missions will be presented. The need for technological evolutions will be examined for each mission. Some evolutions imply only minor changes, for example, to cope with some parts obsolescence. Others will require increasing instrument capabilities compared to those of the ACE instrument. These different technological evolutions will be presented.
Missions and Sensing II
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Architecting constellations of 'operational' earth monitoring satellites (Part II)
Douglas B. Helmuth, Raymond M. Bell, David A. Bennett, et al.
Understanding the earth"s climate and collecting suitable signatures over the next 10, 20, 30 years is a shared objective of many world governments. But even with significant scientific progress and demonstrations to date, there remains a daunting challenge to bridge from scientific missions to "operational" systems that support decision makers, scientific communities and vast numbers of users eager for verified data. In this part II paper for 2010, an expanded description of a system of constellations reveals the capacity of supporting multiple existing missions and additional "decadal survey" objectives, by leveraging today's capabilities in an expandable architecture. Resourcing a system of systems solution is also challenging, but thoughts on shared cost efficiencies and common concerns will be offered specifically intended to focus the "community" discussion on incremental solutions.
Development of immersed diffraction grating for the TROPOMI-SWIR spectrometer
A. H. van Amerongen, H. Visser, R. J. P. Vink, et al.
We have developed a novel diffraction grating based on lithographical techniques and anisotropic etching in silicon. The grating is designed for the short-wave-infrared channel of the TROPOMI imaging spectrometer that will be launched on ESA's Sentinel 5 Precursor mission to monitor trace gases in the earth atmosphere. Stringent requirements on both the imaging properties and the quality of the spectra translate to a high-tech grating. In our design the dispersion and resolution is increased with a factor 3.4 with respect to conventional gratings by using the grating in immersion, such that diffraction takes place inside the silicon grating material. By lithographic patterning and anisotropic etching of the mono-crystalline silicon we precisely control line spacing and blaze angle. The grating has a line spacing of 2.5 μm and is operated in sixth order. We show that an efficiency of 60% is reached on a 50 x 60 mm2 grating surface. We compare our test results with numerical calculations for grating efficiency for both polarizations and find good agreement.
High-precision scanner control system
Y. Yanagita, K. Aoki, T. Kurii
A high-precision whiskbroom scanner control system, which is used on earth observation satellites, is discussed. This control system is required to keep high angular precision with ultra-smooth rotation. We designed a feedback control system consisting of a rate loop for rotation-speed control and a position loop for angular control. Adding a feedforward control system using cyclic memory, 1st order rotational synchronizing disturbance caused by eccentric load has been compressed over 50 dB. As a result, high pointing accuracy with a standard deviation of 0.003 degree or less has been achieved in rotating with a constant speed of 79.4 rpm.
Completely optical orientation determination for an unstabilized aerial three-line camera
Aerial line cameras allow the fast acquisition of high-resolution images at low costs. Unfortunately the measurement of the camera's orientation with the necessary rate and precision is related with large effort, unless extensive camera stabilization is used. But also stabilization implicates high costs, weight, and power consumption. This contribution shows that it is possible to completely derive the absolute exterior orientation of an unstabilized line camera from its images and global position measurements. The presented approach is based on previous work on the determination of the relative orientation of subsequent lines using optical information from the remote sensing system. The relative orientation is used to pre-correct the line images, in which homologous points can reliably be determined using the SURF operator. Together with the position measurements these points are used to determine the absolute orientation from the relative orientations via bundle adjustment of a block of overlapping line images. The approach was tested at a flight with the DLR's RGB three-line camera MFC. To evaluate the precision of the resulting orientation the measurements of a high-end navigation system and ground control points are used.
FPA I
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Two-dimensional focal plane detector arrays for LWIR/VLWIR space and airborne sounding missions
S. Hanna, A. Bauer, H. Bitterlich, et al.
An increasing need for high-precision atmospheric data especially in the long wavelength infrared (LWIR) and very long wavelength infrared (VLWIR) spectral ranges has arisen in the past years not only for the analysis of climate change and its effect on the earth's ecosystem, but also for weather forecast and atmospheric monitoring purposes. Spatially and spectrally resolved atmospheric emission data are advantageously gathered through limb or nadir sounding using an imaging Fourier transform (FT) interferometer with a two-dimensional (2D) high-speed focal plane detector array (FPA). In this paper, AIM reports on its latest results on MCT VLWIR FPAs for Fourier transform infrared sounding applications in the 8-15μm spectral range. The performance of a (112x112) pixel photodiode array with a 40μm pixel pitch incorporating extrinsic p-doping for low dark current, a technique for linearity improvement at high photon fluxes, pixel guards, pixel select/de-select, and a (2x2) super-pixel architecture is discussed. The customized read-out integrated circuit (ROIC) supporting integrate while-read (IWR) operation has a buffered direct injection (BDI) input stage and a full well capacity (FWC) of 143 Megaelectrons per super-pixel. It consists of two independently operating halves with two analog video outputs each. The full frame rate is typically 4k frames/sec, making it suitable for use with rapid scan FT infrared spectrometers. At a 55K operating temperature and an ~14.4μm cut-off wavelength, a photo response of 12.1mV/K and a noise equivalent temperature difference of 24.8mK at half well filling are demonstrated for a 286K reference scene. The nonlinearity error is <0.5%.
Sofradir detectors for hyperspectral applications from visible up to VLWIR
Bruno Fièque, Philippe Chorier, Bertrand Terrier
Sofradir is involved in the manufacturing of the detector for PRISMA mission. Thanks to this experience, Sofradir has extended its Visible-Near infrared technology, called VISIR. This technology has the huge advantage to enable detection in both visible range and SWIR detection range (0.4μm up to 2.5μm). This 1000x256 array has been especially developed and dedicated for hyperspectral application. MCT Technologies at Sofradir covers also MWIR and LWIR infrared ranges for many years. Detectors for space applications have been already developed and validated and are currently running. For example, 1000x256 or 500x256 arrays 30 μm pitch (called Saturn or Neptune detectors) have already been validated in terms of irradiation behavior, thermal cycling, and ageing. Sofradir is now able to present a large MWIR or LWIR 1016x440 array with a 25μpixel pitch. This detector is also dedicated to hyperspectral application. Thus, with this new detector, Sofradir covers infrared ranges from Visible to VLWIR. After a brief reminding of the current VISIR focal plane array [1], and latest results from this detector, we will present in this paper the 1016x440 new array. The architecture and functionalities of this 1016x440 array will be presented and also the proposed packaging for this detector. Then, main general required performances and previous electro-optical characterizations will be also described.
LWIR and VLWIR detectors development at SOFRADIR for space applications
Bertrand Terrier, Anne Delannoy, Philippe Chorier, et al.
SOFRADIR is one of the leading companies involved in the development and manufacturing of infrared detectors. Its offer covers the infrared spectrum from visible range (0.4 μm) up to very long wavelength range (15 μm). The need in this last field is driven by space activities, especially by meteorological instruments using imagery or spectrometry. In the frame of Meteosat Third Generation mission, ESA has launched pre-development activities to address the critical equipments for risk reduction. VLWIR detectors for FCI and IRS have been considered as challenging ones and thus SOFRADIR has been involved for manufacturing and testing 2D arrays with long cut-off wavelength (14.9μm at 50K) in order to evaluate their compliance to MTG requirements as far as dark current behaviour, quantum efficiency, photoresponse uniformity, spatial response, operability and reliability are concerned. In parallel, trends of space and tactical applications call for dark current reduction technology in order to improve systems performances in terms of operating temperature and signal to noise ratio. In the frame of its common laboratory DEFIR with CEA-LETI, Sofradir has developed a new MCT p on n technology to answer this need. First demonstrations were made with success (640x512, pitch 15μm and cut-off 9.5μm) and Sofradir is now industrializing this technology in particular for tactical application. Thanks to the communality between space and tactical activity at Sofradir, these results will benefit advantageously also to space activity. In this paper, we present a review of latest Sofradir results concerning LWIR and VLWIR technology. In particular, latest data, concerning development and characterization of generic VLWIR technology up to 15 μm cut-off wavelength, are presented as well as data concerning the promising p on n LWIR technology.
Enhanced broadband (11-15 µm) QWIP FPAs for space applications
Alexandru Nedelcu, Ybe Creten, Vincent Guériaux, et al.
The European Space Agency is currently funding a project led by Alcatel-Thales III-V Lab, intended to develop high performance, broadband (11-15μm) Quantum Well Infrared Photodetectors (QWIPs) and optimised read-out circuits for Earth Observation and Planetary Science missions. In this talk we will present an exhaustive study of the performance achieved on QWIP layers designed for dispersive spectro-imagers (narrowband detectors) as well as Fourier Transform spectro-imagers (broadband detectors). The performance is calculated based on the electro-optical characteristics of the QWIP layers, the technical requirements and the read-out characteristics coming from the predevelopment phase. In the read-out predevelopment phase SPICE simulation transistor model parameters have been extracted valid for an adequate circuit simulation at the required operating temperature range. Different read-out architectures have been studied to attain the final demonstrator's requirements. As a result of this study, two different pixel topologies have been retained which will be implemented as 128x256 sections in the 256x256 pixel demonstrator. The roadmap for the next project steps will also be presented.
Development of multi-spectral QWIPs for extrasolar planets imaging
One of the most promising approaches for direct imaging of extrasolar planets is based on the next generation of extremely large ground-based telescopes and original differential observing techniques to overcome atmospheric fluctuations problems. One possibility is the use of phase-mask coronagraphy coupled with spectral differential imaging. Multispectral Quantum Well Infrared Photodetectors (QWIPs) are a promising technological solution that could answer the stringent requirements of this challenging topic. We present here the scientific background, the technical requirements as well as the possible technical approaches that are explored in the frame of a project funded by the ANR (Agence Nationale de la Recherche). In particular, we will describe the strategy retained for the design of the QWIP active layer.
FPA II
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The design, manufacture and characterization of the SWIR channel detector for the Proba-V mission
Jonas L. Bentell, Peet Verbeke, Koen Vanhollebeke, et al.
Proba-V is a Belgian mini-satellite, designed to bridge the gap between the present Spot-Vegetation Mission and the future GMES Sentinel missions. In order to continue the information gathering the earth surface shall be scanned in 3 Vis/NIR bands and 1 SWIR band. In this paper we will mainly focus on the development of the SWIR band FPA, whereas other contributors will discuss more in detail the mission and the overall optical concept. The SWIR FPA is a long linear array of 68 mm, as long as the visual detector array; due to the fact that the SWIR FPA is a hybrid one with a detector array and a silicon readout circuit, the resolution of the SWIR array is halved wrt the visible array. InGaAs, grown lattice matched on an InP substrate and operated at room temperature, is selected as the baseline detector material. Due to the length of the linear array w.r.t. the InGaAs wafer size; it was decided to compose the overall FPA of several subparts. During the architecture study, it was decided to aim for a mechanically butted array with 3 staggered sensors lines, which are separated by 1.5 mm. App 140 pixels are foreseen in the overlap in order to realign the ground information. The pixel alignment over the full array can be maintained within the following error margins: in plane (X- and Yorientation) : ≤ 25 μm and out of plane (Z-direction): &≤ 100 μm. The detectors are wire bonded to the Silicon readout circuit. The detector interface is a CTIA with selectable gain or sensitivity. The nominal Feedback capacitor is 600 fF, resulting in a sensitivity of 270 nV/e-. The analog signal path is further equipped with a CDS stage and a S&H bank. The power dissipation of the array in slow scan mode is below 300 mW per module or < 900 mW for the FPA. The noise of the array is measured to be below 1 mVrms on a signal swing of 2 Vptp , resulting in a circuit dynamic range of >2000:1..
Design of CMOS sensor fill factor for optimal MTF and SNR
Cynthia Liu, Jer Lin, Michael Tseng
With the self-developing CMOS sensors in the instrument Focal Plane Assembly, there is flexibility in the trade-off for optimal specifications of CMOS sensor. Among the specifications, fill factor is a key item. It affects not only the window effect in FPA MTF (static), but also the smearing effect in dynamic MTF. Different rectangular shape of the pixel active area was studied for estimating the cross-track and along-track MTF. For TDI sensor, higher fill factor leads to less stage number or higher SNR, but less system MTF value; while less TDI stage number will improve the system MTF due to satellite pointing stability. This work is to present the analysis results about fill factor and stage number of TDI CMOS sensor.
Analytical modeling of MTF and QE of CCD and CMOS image sensors
Ibrahima Djité, Pierre Magnan, Magali Estribeau, et al.
Today, CCD and CMOS image sensors have found many applications in general public domains. However their use for scientific and space applications requires high electro optical performances and strong abilities to predict them prior to the image sensors design and conception. Sensitivity and image quality are two important electro-optical characteristics for an image sensor. The Quantum Efficiency (QE) and the Modulation Transfer Function (MTF) are respectively the common metrics used to quantify them. Because of an important number of parameters influencing the MTF and the QE, their analytical calculation is not an easy task. This paper describes an analytical model of MTF and QE of CCD and CMOS image sensors. The model has been developed in order to take into account a maximum number of parameters: pixel size, photosensitive area size and shape, EPI-layer and substrate doping concentration, junction depth. The effect of top layer oxide stacks on the resulting optical transmission coefficient and so on QE can also be taken into account. The study is established in the case of CMOS photodiode pixels and buried channel CCD pixels. The MTF and QE modeling results are compared with experimental results. MTF and QE measurements are realized on different pixels types having different photosensitive area shapes and using different technologies. A part of these measurements are performed on a frontside-illuminated CMOS sensor and on a thinned backside-illuminated CMOS image sensor, both of them are manufactured using CMOS technology dedicated to image sensors. The other part of MTF and QE measurements are performed on thinned backside-illuminated N-buried channel CCD sensor. Finally the MTF and QE models are used to make performance predictions, and the effects of various parameters on the MTF and the QE are discussed.
CMOS detectors for space applications: from R&D to operational program with large volume foundry
P. Martin-Gonthier, P. Magnan, F. Corbiere, et al.
Nowadays, CMOS image sensors are widely considered for space applications. The use of CIS (CMOS Image sensor) processes has significantly enhanced their performances such as dark current, quantum efficiency and conversion gain. However, in order to fulfil specific space mission requirements, dedicated research and development work has to be performed to address specific detector performance issues. This is especially the case for dynamic range improvement through output voltage swing optimisation, control of conversion gain and noise reduction. These issues have been addressed in a 0.35μm CIS process, based on a large volume CMOS foundry, by several joint ISAE- EADS Astrium R&D programs. These results have been applied to the development of the visible and near-infrared multi-linear imager for the SENTINEL 2 mission (LEO Earth observation mission for the Global Measurement Environment and Security program). For this high performance multi-linear device, output voltage swing improvement is achieved by process optimisation done in collaboration with foundry. Conversion gain control is also achieved for each spectral band by managing photodiode capacitance. A low noise level at sensor output is reached by the use of an architecture allowing Correlated Double Sampling readout in order to eliminate reset noise (KTC noise). KTC noise elimination reveals noisy pixels due to RTS noise. Optimisation of transistors's dimensions, taking into account conversion gain constraints, is done to minimise these noisy pixels. Additional features have been also designed: 1) Due to different integration times between spectral bands required by mission, a specific readout mode was developed in order to avoid electrical perturbations during the integration time and readout. This readout mode leads to specific power supply architecture. 2)Post processing steps can be achieved by alignment marks design allowing a very good accuracy. These alignment marks can be used for a black coating deposition between spectral bands (pixel line) in order to minimise straight light effects. In conclusion a review of design improvements and performances of the final component is performed.
FPA III
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Hybrid avalanche photodiode ranging and photon-counting altimeter
B. Dierickx, S. Bellis, N. Witvrouwen, et al.
Avalanche photodiodes are very well suited and extensively used for low light application. In this paper we present a devise using avalanche photodiodes in conjunction with a pulsed laser-source to be used as an optical altimeter. The extreme sensitivity of a dedicated silicon SPAD array is combined with a versatile standard CMOS readout circuit to achieve unique performances. This imaging device is able to perform ranging with four centimeters accuracy over five kilometers distance. It is also capable of delivering quantum limited images. Development of the readout circuit will be disclosed as well as measurement results performed on the final device.
Evaluation of 10MeV proton irradiation on 5.5 Mpixel scientific CMOS image sensor
We evaluate the effects of 10 MeV proton irradiation on the performance of a 5.5 Mpixel scientific grade CMOS image sensor based on a 5T pixel architecture with pinned photodiode and transfer gate. The sensor has on-chip dual column level amplifiers and 11-bit single slope analog to digital converters (ADC) for high speed readout and wide dynamic range. The operation of the sensor is programmable and controlled by on-chip digital control modules. Since the image sensor features two identical halves capable of operating independently, we used a mask to expose only one half of the sensor to the proton beam, leaving the other half intact to serve as a reference. In addition, the pixel array and the digital logic control section were irradiated separately, at dose rates varying from 4 rad/s to 367 rad/s, for a total accumulated dose of 146 krad(Si) to assess the radiation effects on these key components of the image sensor. We report the resulting damage effects on the performance of the sensor including increase in dark current, temporal noise, dark spikes, transient effects and latch-up. The dark signal increased by about 55 e-/pixel after exposure to 14 krad (Si) and the dark noise increased from about 2.75e- to 6.5e-. While the number of hot pixels increased by 6 percent and the dark signal non uniformity degraded, no catastrophic failure mechanisms were observed during the tests, and the sensor did not suffer from functional failures.
Radiation damages in CMOS image sensors: testing and hardening challenges brought by deep sub-micrometer CIS processes
Vincent Goiffon, Cédric Virmontois, Pierre Magnan, et al.
This paper presents a summary of the main results we observed after several years of study on irradiated custom imagers manufactured using 0.18 μm CMOS processes dedicated to imaging. These results are compared to irradiated commercial sensor test results provided by the Jet Propulsion Laboratory to enlighten the differences between standard and pinned photodiode behaviors. Several types of energetic particles have been used (gamma rays, X-rays, protons and neutrons) to irradiate the studied devices. Both total ionizing dose (TID) and displacement damage effects are reported. The most sensitive parameter is still the dark current but some quantum efficiency and MOSFET characteristics changes were also observed at higher dose than those of interest for space applications. In all these degradations, the trench isolations play an important role. The consequences on radiation testing for space applications and radiation-hardening-by-design techniques are also discussed.
EarthCARE BBR detectors performance characterization
The Broadband Radiometer (BBR) is an instrument being developed for the ESA EarthCARE satellite. The BBR instrument objective is to provide measurements of the reflected short-wave (0.25-4.0 μm) and emitted long-wave (4.0- 50 μm) TOA radiance over three along-track views (forward, nadir and backward). The instrument has three fixed telescopes, one for each view, each containing a broadband detector. Each detector consists of an uncooled focal plane array (FPA) hybridized with a readout integrated circuit (ROIC) and a proximity electronics circuit-card assembly (CCA) packaged in an aluminum base plate with cover. The detectors, based on INO's VOx microbolometer technology, are required to provide fast pixel response time (< 6 ms), uniform spectral response over the entire spectral range (achieved by the development of a gold black absorber), and low NEDT under the instrument operating conditions. The detectors development has now passed the critical design review (CDR) and various development units (among which the most recent is the engineering model (EM)) have been shown to meet the specification requirements. This paper first provides a description of the detector design, followed by its principles of operation. It further presents and discusses measurement and analysis results for the performance characterization of the engineering model in the context of the applicable requirements.
Evaluation of a COTS Microbolometers FPA to space environments
H. Geoffray, G. Quadri, L. Tauziede, et al.
Microbolometers Focal Plane Arrays (FPA) are uncooled infrared arrays suitable for the detection in the 8-14μm spectral range. Standard products show attractive performances and are available at low cost. They can be consistently used for space missions on microsatellites. A microbolometers focal plane array (a 640x480 microbolometer array with a pitch of 25 μm) is foreseen to be used on the Mistigri mission proposed by CNES (French National Space Agency). The scientific objectives of the mission are the monitoring of water conditions of agricultural crops and natural vegetation. These objectives can be reached thanks to observations in the thermal infrared wavelength. Mistigri is now at an early stage of development (preliminary definition study). CNES has started a technological evaluation on the microbolometers array as a risk mitigation action. This technological evaluation plan includes radiation tests (ionizing dose, displacement damage, and heavy ions), lifetest, thermal cycling and vibrations and shocks. At the same time we have addressed fine performances of the microbolometers arrays in order to optimize instrument design and performances.
Joint Session: Airborne Remote Sensing: Programs and Data Sets
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EUFAR, the European Facility for Airborne Research, becomes 10
I. Reusen, J.-L. Brenguier
Instrumented aircraft are essential tools in environmental and geo-sciences. Many European countries operate their own research aircraft, but access across national boundaries is difficult and not all researchers are familiar with the potential advantages of airborne experiments. Two Framework Programme 6 (FP6) initiatives i) HYRESSA, HYperspectral REmote Sensing in Europe Specific support Action, and ii) EUFAR, EUropean Facility for Airborne Research in Environmental and Geo-sciences, have joined forces in Framework Programme (FP7). The FP7 EUFAR project (2008- 2012) is now a network of 33 European airborne data providers and experts in airborne measurements and aims at providing and improving the access to airborne facilities (i.e. aircraft, airborne instruments, data processing centers) through Trans-national Access (TA) Activities, Networking Activities (NA) and Joint Research Activities (JRA). Its aim is to integrate the airborne community to ensure that researchers in environmental and geo-sciences may have access to infrastructure most suited to their needs, irrespective of the location of the infrastructure. EUFAR will celebrate its 10th anniversary during the ICARE International Conference on Airborne Research for the Environment including international air show which will be held in Toulouse (France) from 25-31 October 2010.
Calibration I
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Aqua MODIS 8-year on-orbit operation and calibration
Launched in May 2002, the NASA EOS Aqua MODIS has successfully operated for more than 8 years. Observations from Aqua MODIS and its predecessor, Terra MODIS, have generated an unprecedented amount of data products and made significant contributions to studies of changes in the Earth's system of land, oceans, and atmosphere. MODIS collects data in 36 spectral bands: 20 reflective solar bands (RSB) and 16 thermal emissive bands (TEB). It has a set of on-board calibrators (OBC), providing sensor on-orbit radiometric, spectral, and spatial calibration and characterization. This paper briefly summarizes Aqua MODIS on-orbit operation and calibration activities and illustrates instrument onorbit performance from launch to present. Discussions are focused on OBC functions and changes in detector radiometric gains, spectral responses, and spatial registrations. With ongoing calibration effort, Aqua MODIS will continue serving the science community with high quality data products.
Terra MODIS band 2 electronic crosstalk: cause, impact, and mitigation
J. Sun, X. Xiong, N. Che, et al.
The MODerate-resolution Imaging Spectroradiometer (MODIS) is one of the primary instruments in the Earth Observing System (EOS). The first MODIS instrument was launched in December, 1999 on-board the NASA EOS Terra spacecraft. MODIS has 36 bands, covering a wavelength range from 0.4 μm to 14.4 μm. MODIS collects data at three spatial resolutions: 0.25 km (2 bands), 0.5 km (5 bands), and 1 km (29 bands). In the Earth scene images of Terra MODIS band 2 (0.85μm), two sets of regularly distributed anomalous pixels are observed in each scan, of which one is brighter and the other is darker than surrounding pixels. MODIS band 2 is a 0.25 km resolution band, having 40 detectors and 4 subframes for each detector. The brighter dots correspond to the subframe 1 pixels of detector 30 and the darker dots correspond to the same subframe of detector 29. In this manuscript, it is demonstrated that the anomaly is due to electronic crosstalk. The sending bands and detectors for the crosstalk are identified using lunar images and are confirmed using the Spectroradiometric Calibration Assembly (SRCA) observations. A linear algorithm is developed to describe the crosstalk, and crosstalk coefficients are derived using lunar observations. With the derived coefficients, the dotted features in Earth view images of Terra band 2 can be significantly reduced.
Tracking long-term stability of the response versus angle for the MODIS thermal emissive bands with observations over clear ocean
This study uses observed brightness temperatures (BT) over clean ocean to track the stability of the onorbit response versus scan angle (RVS) for the thermal emissive bands (TEB) of the MODIS (the Moderate Resolution Imaging Spectroradiometer) instrument onboard Aqua and Terra spacecraft. The stability is examined by tracking the BT difference between those obtained at each scan angle and the scan angle of the view for the onboard blackbody. Over two thousands granules over the Atlantic Ocean for Terra and Aqua MODIS are used. Cloudy pixels within each granule are excluded to improve trending quality and consistency. The BT trends are derived at 13 angles of incidence (AOI) over the entire Aqua and Terra missions. Results show that the relative changes in BT for the long-wave infrared bands are within a few tenths of a degree, equivalent to 0.5 to 1.0%, while those for a few middle-wave infrared bands still show large fluctuations due to their high sensitivity to atmospheric water vapor contents. A comparison with trends obtained using measured BT for instrument interior cavity shows that both results are in good agreement. The BT differences between two mirror sides at each scan angle are also derived to examine the consistency of the RVS results.
Time-dependent response versus scan angle and its uncertainty for MODIS reflective solar bands
J. Sun, X. Xiong, H. Chen, et al.
Two MODIS instruments are currently onboard NASA's EOS Terra and Aqua spacecraft. MODIS has 20 reflective solar bands (RSB), which cover a spectral range from 0.41 to 2.2 micron. The RSB are calibrated on-orbit by an onboard solar diffuser (SD) whose degradation is tracked by a solar diffuser stability monitor (SDSM), an onboard spectroradiometric calibration assembly (SRCA) and monthly lunar observations through the instrument's space view (SV) port. MODIS views the Earth surface, SV, and the onboard calibrators via a two-sided scan mirror. The reflectance of the scan mirror depends on the angles of incidence (AOI) as well as the wavelength of the incident light. The dependence of the scan mirror's reflectance on the AOI is described by the response versus scan angle (RVS), which was measured prelaunch for both Terra and Aqua MODIS RSB. Analysis of the SD, lunar, and SRCA calibrations shows that the RVS was changing on-orbit and the changes are strongly AOI dependent for short wavelength bands. Algorithms have been developed to track the on-orbit RVS change using the SD, Moon, and SRCA observations as well as the Earth view (EV) response mirror side ratios and to derive the time-dependent RVS look-up tables (LUT) for the RSB calibration in the MODIS Level 1B (L1B) algorithm. Time-dependent RVS has been applied to MODIS RSB since MODIS L1B Version 4 and has been improved in Version 5 and Version 6 for both Terra and Aqua MODIS. This report reviews MODIS RSB RVS algorithms based on the most recent MODIS L1B Version (Version 6), derives the RVS uncertainties at the AOIs of the SD and SV, and estimates the uncertainties at other AOI. For most RSB, the reflectance calibration uncertainties are less than the 2% specification. For some of the shorter wavelength bands, especially in Terra MODIS, the reflectance calibration uncertainties is seen to be greater than 2% in recent years at some AOI between the SD and the SV.
Using CEOS reference standard test sites to track the calibration stability of NOAA-19 AVHRR reflective solar channels
In recent years, there is an increasing interest to establish a global integrated network of calibration sites for the purpose of tracking sensor performance, conducting cross-sensor comparison and assessing data quality and consistency. Based on such a need, the Committee on Earth Observation Satellites (CEOS) proposed eight instrumented sites for which surface measurements can be acquired through field campaigns and five pseudo-invariant desert sites typically consisting of sand dunes. In this study, we select one site from each category to study the calibration stability of reflective solar channels of NOAA- 19 Advanced Very High Resolution Radiometer (AVHRR) (launched on February 6, 2009). Since AVHRR does not have an onboard calibrator for the reflective solar channels and vicarious calibration often needs long-term observations to derive reliable trends, this study will provide an early assessment of sensor on-orbit calibration performance and establish a preliminary trend to examine its calibration consistency with other sensors. The Antarctic Dome C site is selected primarily to monitor the on-orbit calibration performance whereas Libya 4 test site is used to evaluate the cross-calibration consistency of AVHRR with other sensors. A site-specific Bi-directional Reflectance Distribution Function (BRDF) model developed based on observations made by Moderate Resolution Imaging Spectroradiometer (MODIS) is used to normalize AVHRR observed Top-of-Atmosphere (TOA) reflectances. Impact due to calibration applied to NOAA-19 AVHRR L1B is assessed separately using a constant detector response. Results show that for NOAA-19 AVHRR solar channels 1 and 2, variations in reflectance during the first year after launch are still around 6% and more than 10%, respectively, either due to sensor change or improper adjustment of calibration coefficients. While two sites provide consistent trends for the visible channel, the Dome C site is more suitable for the near-infrared channel as impacts of the absorption by atmospheric water vapor are minimal.
Calibration II
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The CEOS Cal/Val Portal: a new instrument for the cal/val community
Alessandro Burini, Nigel Fox, Gyanesh Chander, et al.
The exploitation of Earth Observation data depends with increasing importance on multi-source inter-calibrated data, as demonstrated, for example, in the ESA DUE GlobColour project.1 The subgroup on Calibration and Validation of the Committee on Earth Observing System (CEOS) formulated a recommendation during the plenary session held in China at the end of 2004, with the goal of setting-up and operating an Internet based system to provide sensor data, protocols and guidelines for the purposes of efficiently supporting sensor calibration, inter-calibration and product validation. ESA has taken the initiative and launched the version 1.0 of the Cal/Val Portal in October 2006 and the version 2.0 in mid 2009. This paper describes the Cal/Val portal webpage, components, and general content organization. It also gives an example of collaboration and Cal/Val facility.
Multiple vicarious calibration using combined accuracy estimation
Stefan Livens, Sindy Sterckx, Wouter Dierckx, et al.
Radiometric calibration often employs several independent vicarious calibration techniques to increase robustness and accuracy. We present a statistical methodology for combining results in a hierarchical scheme. The method, developed for the PROBA-V remote sensing mission, is based on handling and propagating of accuracies in accordance with the ISO GUM. Robust estimation is performed and outliers removed. Results over different sites are combined using weighted averaging. Weighted linear regression is used for temporal averaging. Results from different methods are combined taking into account possible bias. Finally an operational update strategy is proposed which relies on a significance criterion.
Characterization of a double monochromator
Optical spectroradiometers used to measure and monitor the radiance output of uniform sources must be thoroughly characterized. The viability of the use of an instrument for such purposes is based upon the establishment of knowledge of its radiometric responsivity characteristics. The NASA Goddard Space Flight Center Radiometric Calibration Laboratory (RCL) has commissioned a new spectroradiometer for use in measurements of irradiance and radiance sources. The spectroradiometer is comprised of a commercial scanning grating, Czerny-Turner double monochromator. This spectroradiometer has been used to make measurements on a number of irradiance and radiance sources over the wavelength range of 300 to 2400 nm. Instrument characterization included determination of stability, functional wavelength calibration and scattered light performance. Comparison measurements were also made with other radiometers. The data gathered from these measurements is presented, analyzed, and discussed.
Onboard spectral calibration for the Japanese hyper-spectral sensor
Kenji Tatsumi, Nagamitsu Ohgi, Hisashi Harada, et al.
The Japanese hyper-spectral sensor provides data products covering continuous spectral bands in the wavelength range from 400 nm to 2500 nm. It is characterized by a SNR of > 450 in the VNIR and>300 in the SWIR range at a ground resolution of 30 m x30 m. This report is concerned with the onboard wavelength calibration methods for the Japanese hyper-spectral sensor. As a result of trade study, the combination of a transmission type glass filter containing rare earth oxides, a Mylar polyester film and a quartz tungsten-halogen-lamp was selected. This method covers the wavelength range from 400 nm to 2450 nm. For the purpose of wavelength shift estimation, the method employing the mean square deviation as merit-function was found to be stable and precise. The accuracy of the absorption peak wavelength determination will be expected less than 2% (=0.2 nm) for the VNIR spectral resolution and 5% (=0.625 nm) for the SWIR spectral resolution.
Global Earth Observation System of Systems
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A remote sensing model of construction-related soil disturbance in southern Arizona
Frederick S. Pianalto
Construction-related soil disturbance, such as road construction, trenching, landstripping, earthmoving and blasting, is a significant source of fugitive (or airborne) dust, and fugitive dust is a potential health hazard as well as a primary cause of decreased air quality. Presented here is a remote sensing change detection method using annual Landsat Thematic Mapper (TM) images spanning 1995 and 2009 over southern Arizona to identify and characterize construction-related soil disturbance. To guide development of the remote sensing method, spatial coordinates of construction activity permit inspections performed by a local environmental quality agency to control fugitive dust are obtained and processed in a GIS. Satellite change detection methods are compared with kernel density plots of the construction activity inspection points. Band differencing in the mid-infrared spectral region (TM band 5), with a change threshold of four standard deviations above and below the change image mean, is identified as a simple and effective method to identify construction-related soil disturbance. As an accuracy assessment, buffers of 920 meter radius were generated around each dust inspection point and around an equal number of random points in a GIS. The dust inspection point buffers captured statistically significantly more of the remote sensing change pixels as compared to random point buffers (P < 0.0001 in a Mann-Whitney rank sum U-test for each year compared; 44.3% change pixel capture rate average as compared to 16.2% for random points). The remote sensing model is used to estimate location and annual surface area of construction-related soil disturbance in eastern Pima County, Arizona during the fourteen year study period. With limited preprocessing and processing requirements, the proposed model is simple to perform and may be suited for public and other environmental and health agencies to identify and assess fugitive dust sources and inputs to total ambient dust predictive models.
Monitoring of ambient fine particulate matter concentrations from space: application to European and African cities
Jean-Francois Léon, Cathy Liousse, Corinne Galy-Lacaux, et al.
Air pollution is a major issue for global environment as well as human health and well-being. Recently, satellites which are equipped with relevant air quality instruments have been placed into orbit. In this paper, we first present a review on satellite remote sensing of particulate pollution. We then present new results for Europe and on African cities particulate air pollutants using POLDER satellite data. Based on satellite AOD observations, we show that the number of days exceeding the 15.4 μg/m3 threshold is twice frequent in Ouagadougou, Burkina- Faso than in Paris, France. At the regional scale, we observe that the northern coast of the golf of Guinea is dramatically impacted by poor air quality.
Overview of remote sensing applications for assessing and monitoring natural hazards in Cyprus
This paper highlights the importance of using satellite remote sensing in Cyprus for monitoring and managing natural hazards and public health problems. Satellites are able to quantify physical phenomena associated with earthquakes, water (floods) and fires. Satellite sensors can be utilized by the scientific community for the remote sensing of natural hazards over a number of spatial and temporal scales. Indeed this study investigates the potential of monitoring and managing such natural hazards in Cyprus by providing several case studies in Cyprus as well as the potential of applying such satellite remote sensing techniques for assessing and monitoring natural hazards in Cyprus. The occurrence of natural hazards such as fires, flooding, droughts, earthquakes and atmospheric dust in Cyprus as well as the availability of cloud-free satellite images due to the location of the island makes the use of satellite remote sensing techniques ideal for monitoring natural hazards.
Satellite remote sensing, GIS and sun-photometers for monitoring PM10 in Cyprus: issues on public health
PM10 and PM 2.5 particles are very significant issues for the public health of the community. Such parameters are measured from air-pollution stations that are scarcely distributed in the Cyprus region. Satellite remote sensing can provide synoptic coverage of the Cyprus area either daily from MODIS sensor or every 16 days from Landsat. Sunphotometers are used to measure the aerosol optical thickness (AOT) on ground during the satellite overpass. Several different campaigns have been made both for two urban areas in Paphos and Limassol area. For the period 28/10/09 - 30/12/09, the regression analysis between PM10 and ΡΜ2.5 for the Paphos town (central) gave coefficient of determination of R2=0,78 and R2=0,61 respectively. Coefficient of determination R2 =0.61 was found for the period May-June 2009 for the centre of Limassol when PM10 was regressed against AOT measured from MICROTOPS handheld sun-photometer. The AOT data retrieved from MODIS AOT (at 550 nm) and CIMEL sun-photometer (AERONET) also provided a high correlation (r=0.9, R2 = 0.81) for the centre of Limassol for April to July 2010 measurements. Results obtained by correlating MODIS AOT (at 550 nm) against hand-held MICROTOPS sun-photometer in the centre of Limassol for the period January 2009 to March 2010 gave R2=0,81. Using the PM10 limit of 50μg/m3 as prescribed by the European Union and the regression model found for the Limassol area, a threshold value of AOT for this area of 0.6 was found. Such value can be used as threshold AOT values for alerts either using the MODIS or Landsat satellite imagery. An example of how a GIS can provide temporal variations of AOT over the Cyprus area is shown.
Poster Session
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Radiometric calibration of multi-spectral scanner of CBERS-1 satellite
Linhua Yang, Shanping Jiang, Rong Zhang, et al.
Beijing Institute of Satellite Environment Engineering has been engaged in the radiometric calibration of satellite remote sensor since 1980s. Recently, one calibration test for the multi-spectral scanner of CBERS-1 resource satellite has just been completed. This test was performed in the KM6 calibration facility, which is the latest one designed for radiometric calibration of satellite infrared sensor in the auxiliary chamber of KM6 environment simulator. In this test, a set of multi-spectral sources were used, which include a solar integrating sphere whose spectrum covers the visible light and near infrared, and a blackbody whose spectrum covers the far infrared. For performing the multi-spectral radiometric calibration in one test, the multi-spectral optical system was used. By controlling the precision mechanism in the vacuum cryogenic environment, the multi-spectral optical system can be switched, and the light from integrating sphere or blackbody can be individually reflected to the scanner. This paper mainly describes some technologies of the multi-spectral sources, the multi-spectral optical system and etc in this test.
Remote sensing CubeSat
Ayman A. Mahmoud, Tamer T. Elazhary, Amal Zaki
Satellite images help in studying various phenomena related to earth's surface. The range of applications varies from agriculture, geology, coast and marine studies to urban development and environmental affairs. CubeSat projects belong to the category of small satellites named Pico Satellites. They have a relative superiority over higher order satellites such as Micro and Mini satellites in terms of their short development time, lower complexity, and most importantly less cost. We present here an overview on the ongoing project EgyCubeSat-1, a Pico satellite that has a camera as an optical payload with ground sample distance better than 100 meters, synchronous orbit, and low earth orbit in the range 600 ~ 700 Km. The key innovation is the development of costumed optics that fit in the compact allocated space and result in better resolution.
Sub-pixel registration method for phase diversity wavefront sensor using spatial light modulator
The purpose of this paper is to develop sub-pixel registration method for adaptive optics system using phase diversity wavefront sensing with a spatial light modulator (SLM). The SLM which is used for wavefront compensation applies multiple time-series known wavefronts as a priori information to the optical system. By using the SLM for the phase diversity generator, it is possible to select the optimal number and shape of phase diversities for various kinds of natural modes of wavefront aberrations which are represented by the Zernike polynomials. In this case, a misregistration of several diversity images has to be compensated before using phase diversity algorithm. We extracted phase diversity method to estimate not only wavefront aberration but also parallel shift between images simultaneously. The suggested method was validated by numerical simulations, and the high estimation accuracy of the distorted wavefront was demonstrated, and nearly diffraction limited images were acquired by wavefront compensation by preventing noise due to misregistrations.
Preliminary assessment of several parameters to measure and compare usefulness of the CEOS reference pseudo-invariant calibration sites
Test sites are central to any future quality assurance and quality control (QA/QC) strategy. The Committee on Earth Observation Satellites (CEOS) Working Group for Calibration and Validation (WGCV) Infrared Visible Optical Sensors (IVOS) worked with collaborators around the world to establish a core set of CEOS-endorsed, globally distributed, reference standard test sites (both instrumented and pseudo-invariant) for the post-launch calibration of space-based optical imaging sensors. The pseudo-invariant calibration sites (PICS) have high reflectance and are usually made up of sand dunes with low aerosol loading and practically no vegetation. The goal of this paper is to provide preliminary assessment of "several parameters" than can be used on an operational basis to compare and measure usefulness of reference sites all over the world. The data from Landsat 7 (L7) Enhanced Thematic Mapper Plus (ETM+) and the Earth Observing-1 (EO-1) Hyperion sensors over the CEOS PICS were used to perform a preliminary assessment of several parameters, such as usable area, data availability, top-of-atmosphere (TOA) reflectance, at-sensor brightness temperature, spatial uniformity, temporal stability, spectral stability, and typical spectrum observed over the sites.
Image simulator for spatially imaging Fourier Transform spectrometer 'HJ1A-HSI'
The simulation of remote sensing images is a useful tool for a variety of tasks, such as the definition of future Earth Observation systems, the optimization and evaluation of instrument specifications, especially for a new type sensor, and the development and validation of data processing algorithms. A scene simulator for optical hyperspectral data from 'HJ1A-HSI' is described in this paper. 'HJ1A-HSI' was carried on the Chinese small satellite HJ-1A, which was successfully launched on September 6th, 2008. Different from common hyperspectral sensor, 'HJ1A-HSI' belongs to the spatial imaging Fourier Transform spectrometer (IFTS). In contrast to the high-speed development of spatial IFTS, the corresponding image simulator is still at the starting stage and the simulation data is very ideal in most cases. To simulate more actual data, a simulation system is proposed in this paper, based on the analysis of spatial IFTS principle. This system puts emphasis on simulating the effects of typical artifacts, and consists of four parts: the calculation of input parameter, the radiance computation for one beam before interfered, the simulation of effects of typical artifacts and the interferogram acquisition. The methodology applied to the complete scene simulation and some sample results are presented and analyzed in this paper.