Advancement of laser-induced fluorescent (LIF) lidar
Author(s):
Yulong Xun
Show Abstract
Since LIF lidar has a higher sensitivity in detecting very thin oil spill, chlorophyll, gebstoff in water, it becomes a useful tool for monitoring marine environment and primary productive forces. Researches indicate especially that it is the unique technique in discriminating the sort of oil spill as comparing to the passive optical and the active microwave remote sensing techniques. In this paper we summarize the state-of-art of LIF lidar technique such as laser sources, optics and return analysis. Then we discuss its potential power in wider application aspects. Some suggestions for developing LIF lidar will be provided and assessed.
Development of the Wuhan lidar system
Author(s):
Zhilin Hu;
Yiping Liu;
Xiong Hu;
Xizhi Zeng
Show Abstract
This paper reports new progress of the Wuhan lidar system. At the present time, our lidar works both at nighttime, to measure the sodium layer in menopause region, and at daytime to measure the aerosol in lower atmosphere region. The daytime working lidar system is equipped with a Faraday Anomalous Dispersion Optical Filter (FADOF), working at the Na resonance line (589 nm) and having an ultra-narrow bandwidth of 2 GHz. The daytime system uses this FADOF to obtain the lidar signal from an altitude of 20 km in our primary experiment. We will also report a comparison of the rms velocity measured by MF radar and Na lidar. A 90% confidence in rms velocity has been achieved.
Lidar measurements of stratospheric aerosol over Hefei, China, during 1991-1996
Author(s):
Huanling Hu;
Jun Zhou;
Yonghua Wu
Show Abstract
The violent eruption of Philippine volcano Pinatubo in mid June of 1991 caused a serious perturbation on the stratospheric aerosols for a long period. In the paper, we report L625 lidar observational results in the period of 1991 - 1996, including evolution of volcano Pinatubo cloud. The time variation and vertical distribution of the volcanic cloud height, thickness, peak-scattering ratio, and integrated backscattering coefficients will be analyzed. L625 lidar measurement data of stratospheric aerosol reveal the characteristics of background period before the volcanic eruption, the evolution of the Pinatubo volcanic cloud, and present new background level.
Multifunction lidar system and its application for detecting aerosol and wind in boundary layer
Author(s):
Liquan Yang;
Jinhuan Qiu;
Siping Zheng;
Qirong Huang
Show Abstract
A backscatter Nd-YAG lidar system has been constructed in our institute, which was designed to measure and image the four- dimensional structure the aerosol and to detect wind in lower atmosphere. It contains a Nd-YAG laser with maximum repetition rate of 15 pulses per second and a 20-cm telescope with maximum field of view of 3 mrad. A fast computer controlled angular scanning system provides can make the lidar to fire at the set position and time. Data logging system provides a logarithmic amplifier of 80 dB, 8 bit A/D conversion with range resolution of 7.5 m and high pixel resolution lidar images in a graphics computer. The system allows observations of inhomogeneities in natural aerosol in boundary layer showing the spatial distribution of aerosol scattering. A model to use triple angle azimuth scan method for measuring wind velocity is developed, which agrees well with the supposed wind in numerical experiment. The lidar system is been used in observations of aerosol and wind in boundary layer during February to July of 1998 and some results are presented.
Concept design of an airborne laser radar's scanner for wind hazard detection
Author(s):
Gang Chen
Show Abstract
A scanner was specifically designed for an airborne laser radar to detect wind hazard. Two plate glasses, which were spun oppositely, were applied to line scan, while a galvanometer scanner was applied to frame scan. This made it possible to maintain a wide scanning field of view (5 degrees X 5 degrees). As well as a large receiving antenna ((phi) 150) and a rapid scan speed (120 lines per second). In this paper, the analyses and calculations of this scanner were reported and the isolation of our optical system was evaluated. Some other scanners were mentioned in comparison with our system.
Compact diode-laser-based sensor for detection of atmospheric methane
Author(s):
Haishan Zhao;
Reinis Kanders;
Robert F. Curl;
Frank K. Tittel
Show Abstract
A portable room-temperature diode laser based on mid-infrared gas sensor was developed for open path measurements of methane in ambient air. This sensor is based on a continuous wave difference-frequency generation in periodically poled LiNbO3 near 3.3 micrometers , pumped by a solitary Fabry Perot type diode laser at 810 nm and a distributed Bragg reflector (DBR) diode laser at 1083 nm. IR frequency tuning between 3045 and 3170 cm-1 was performed by tuning the solitary GaAlAs diode laser. In-situ and open path detection of methane in atmosphere with sensitivity of 18 ppbm/Hz1/2 was performed and detection sensitivity was limited by intensity noise.
Primary analysis of sulphur dioxide pollution and its sources in Chengdu
Author(s):
Hesheng Zhou
Show Abstract
In the early 1980s, the SO2 pollution sources in Chengdu were related to coal consumption. One-third of total annual coal consumption in Chengdu came from Chengdu Coal-fired Power Plant, the largest coal-fired unit. On the basis of the monitoring result of sampling by aircraft over Chengdu in the May of 1984 and the September of 1989, it is found that the distribution of the concentration of SO2 in the upper level of atmospheric boundary layer (ABL) is relevant to the elevated pollution sources of Chengdu Coal-Fired Power Plant and local meteorological condition. However, the concentration of SO2 is normally about 10 ppb from the top of ABL up to an altitude of 4000 m and does not change obviously with the increase of altitude. This may be relevant to the peculiar geographical position and climatological condition of Chengdu.
Raman/Rayleigh/fluorescence lidar for atmosphere measurement
Author(s):
Shunsheng Gong;
Wengang Zheng;
Hongjun Li;
Guotao Yang
Show Abstract
A Raman/Rayleigh/Fluorescence Lidar established in the Wuhan Institute of Physics & Mathematics, China for the measurements of the atmosphere is described, and the preliminary observation results for the lower, upper atmosphere and the sodium layer over Wuhan, China obtained by this lidar are presented in this paper.
Monitoring and analysis of atmospheric environment by remote sensing in mining area
Author(s):
Han Zhen;
Fengjie Yang;
Tao Jiang;
Yong Qing Li;
Liqing Lei
Show Abstract
Mining area is a large and complex system. Only do we adopt routine monitoring methods, the monitoring data that we got cold not reflect atmospheric condition perfectly. The technology of remote sensing can replenish the deficiency of routine environment monitoring methods. However, the quantity variation of vegetation index is correlative with the growing and covering degree of vegetation. With Feicheng's Baizhuang mine as researching area, the authors monitored the atmospheric environment by remote sensing technology adopting normalized vegetation index, analyzed the reflectance spectrum curve of poplar, and calculated the normalized vegetation index. On the basis of above research work, this paper put forward the mathematical relation of atmospheric environment synthesis index and normalization vegetation index, combining the routine analysis of atmospheric pollution. At last, the atmospheric environment of research area was analyzed by the spectrum data and remote sensing data.
Optical method for water pollution remote sensing
Author(s):
Yi He;
Jian Wu
Show Abstract
The random facet physics model is adopted to develop the water wave scattering theory that is used to calculate distributions of the diffusely reflected light from rough air-water surfaces. The depolarization is discussed in detail, which shows that the water surface diffused light is partly depolarized in all direction except the back. For a solid matter surface with strong roughness, even in the back- scattered light, the depolarized component occupies an obvious part. When the local incidence angle (Theta) i satisfies the Brewsterr condition for pure water, the scattered light is line polarized, only the S polarized component can be observed at this direction. In the polluted water case, or something is floating on the water, the received light is partly polarized or even unpolarized at the same direction. These differences suggest us to arbitrate water contamination qualitatively by realizing the received light depolarization.
Applications of 3S technologies for estimating grassland yields in China
Author(s):
Jianlong Li;
Tiangang Liang;
Ping Jiang
Show Abstract
Using green herbage yields, environment and remote sensing (RS) data observed in different grassland types in Fukang County, Xinjiang from 1994 to 1997, the correlation analysis, and estimating grassland yield methods were studied by RS technology and global positioning system (GPS) and geographic information system (GIS) integration (3S). The methods of processing images, analyzing information and linking of RS data with ground grassland data were explored in the paper. The results showed that there existed an obvious correlation between fresh or dry herbage yields and ratio vegetation index (RVI) and normalized difference vegetation index (NDVI) (P less than 0.01) in four grassland types, the correlation coefficients (r) were above 0.679 and passed the F and accuracy test. The results also found that the correlation between fresh or dry grassland yields, and RVI were better than those by NDVI in type II, III and IV, and on the contrary in type I. The optimum nonlinear optical and satellite remote sensing estimating, and forecasting yield models were made from six curve types, the estimating yield accuracies using nonlinear models were better than those using linear models (r equals 0.679 to approximately 0.984 VS r equals 0.479 to approximately 0.722), and the effects were checked by the real observing yields and statistics, the ecological interpretations of the results were given, the total accuracies of the 3S estimating and forecasting green yields were above 75% over large areas, and the objectives were realized by the 3S and grassland expert system integration.
Optical vegetation coverage is a better parameter for estimating vegetation biomass
Author(s):
Peijun Liu;
Lin Zhang;
Ranghui Wang;
Zili Fan
Show Abstract
Optical vegetation coverage can be defined as the ratio of the optical information content of the actual vegetation to that of at the full of vegetation in pixel. Its reflectance model of NOAA/AVHRR is as follows: Cov equals RA2-RA1- rso/RA2V-RA1V-rso Where: Cov is optical vegetation coverage; RA2 and RA1 are respectively the reflectances of the second and the first channel; RA2V and RA1V are respectively the reflectance of the second and the first channel at the full of vegetation; rso is a constant, which is the difference of soil reflectance between the second channel and the first channel. Similarly, its radiance model of NOAA/AVHRR is as follows: Cov equals BA2-BA1-bso/BA2V-BA1V-bso Its geometric meaning is analogous to the ratio of the projection of plant branches and leaves to pixel area. OVC has removed effects of soil background, and shows the weight of vegetation optical information, moreover, it has a uniform standard, as a parameter for estimating vegetation biomass, it is better than DVI, RVI and NVI. This parameter is used to monitor vegetation growing in Xinjiang and achieved good results. In order to extract the spectral information of soil water contents, Cov is used to decompose pixels and removed the vegetation effects.
Geological characteristics in buried coalfields synthetically using remote sensing and non-remote sensing information
Author(s):
Shifeng Dai;
Silong Wang;
Yurong Liu
Show Abstract
With the rapid development of coal industry in China, the emphasis of the geological exploration has been changed from the exposed area to the buried area. Because of the limitation of the geological condition and the exploration methods, it is very difficult to study the geological phenomena in buried coalfield. To the coal geologists in China, to search an effective and practical method has been the important tackle key problem for recent years. In this paper, the authors discussed the characteristics of remote sensing technology in the geological study, and the forming mechanism of remote sensing information in the buried area from the view of agrology and physics, so the important academic evidences were offered for the geological study using remote sensing image in the buried coalfield. The characteristics of the non-remote sensing information, the geophysics information and the basal geological information, were also introduced in the study of buried geological bodies. The authors expounded the general processing method in the investigation of buried geological bodies using remote sensing and non-remote sensing information. At last, the probable distribution area of buried igneous rocks, in Huaibei coalfield in China, were successfully forecasted synthetically using the remote sensing, and non-remote sensing information.
Modified method for assessing geometric distortion of image compression
Author(s):
Zexun Geng;
Zengbo Qian
Show Abstract
Distortions between decompressed image and original remote sensing image can be divided into two parts, geometric degradation and radiometric degradation. The geometric degradation is the error or difference of pixel's position or geometric structure compared with these in original one. Measuring this geometric distortion is very important in some area, such as digital photogrammetry and computer vision, because it is this distortion that influences the position of object. This paper provides a modified method for measuring this distortion on the basis of modified least square (MLS) image match.
Application research for 4D technology in flood forecasting and evaluation
Author(s):
Ziwei Li;
Yutong Liu;
Hongjie Cao
Show Abstract
In order to monitor the region which disaster flood happened frequently in China, satisfy the great need of province governments for high accuracy monitoring and evaluated data for disaster and improve the efficiency for repelling disaster, under the Ninth Five-year National Key Technologies Programme, the method was researched for flood forecasting and evaluation using satellite and aerial remoted sensed image and land monitor data. The effective and practicable flood forecasting and evaluation system was established and DongTing Lake was selected as the test site. Modern Digital photogrammetry, remote sensing and GIS technology was used in this system, the disastrous flood could be forecasted and loss can be evaluated base on '4D' (DEM -- Digital Elevation Model, DOQ -- Digital OrthophotoQuads, DRG -- Digital Raster Graph, DTI -- Digital Thematic Information) disaster background database. The technology of gathering and establishing method for '4D' disaster environment background database, application technology for flood forecasting and evaluation based on '4D' background data and experimental results for DongTing Lake test site were introduced in detail in this paper.
Applications of the deep fracture based on remote sensing and integration processing technology
Author(s):
Ping Wang;
Yong Qing Li;
Yanggui Ou;
Han Zhen
Show Abstract
Through making systematic interpretation of TM images, more and more attentions are paid to North-South trending lineaments in diverse radial, which has the nature of deep fracture. The main application are in follow fields: (1) Establishment of minerogenetic model -- the deep fracture controls not only magmatic intrusion, the distribution of chromium-pyrope and diamond, but also the gold and multi-metal deposit. Thus, this paper gives five kinds of mierogentic models. (2) Exploration of groundwater -- first, at the area lacking of water nearby Zoucheng, it is discovered that plentiful groundwater show a positive correlation with N-S treedig lineaments or with the intersection of two lineaments in North-South and other directions. Second, it is found the terrestrial heat has relation with the fracture, which provides a channel for groundwater. (3) Prevention and harnessment of mine water -- in Fei cheng coal mine, the deep fractures in N-S direction, take disadvantageous part in exploring, in which most of outburst of water occur. The results present a new law for prevention and harnessment water.
Relation between the radiation temperature difference of the Earth's surface and data from satellite picture elements
Author(s):
Youmai Zhu;
BaoSheng Cui;
Yuzhong Ma;
Nanzhi Zou
Show Abstract
In the satellite remote sensing the resolution of the satellite image is always a restriction on the obtaining information and it is impossible that the resolution of pixel is unlimitedly raised. In the infrared region, the pixel values in a uniform picture element isn't effected by the resolution of pixel, but it is another case to some non- uniform picture elements. Each pixel value corresponds to the integration by the radiant excitance of the earth's surface inside of the pixel and is associated with not only the area of same radiation temperature but also the value of radiation temperature inside of the element. In this paper, the relationship between the pixel values and the area of same radiation temperature as well as the value of radiation temperature inside of the pixel was presented. A new train of ideas was given for the obtaining more information by today's resolution of pixel. With the help of this result, the monitor of some natural calamities (for example, the forest fire, the flood, the plant diseases and insect pests, etc.) will become much timely and they could be controlled as soon as possible.
GPS-based target monitoring and navigation system for remote sensing-equipped flying balloon
Author(s):
Dingfa Huang;
Jun Qin
Show Abstract
The data obtained by a balloon borne camera taking photography of the earth can be database inputs of environment and disaster (e.g. landslide, mud-rock flow). It obviously overcomes the disadvantages of low resolving power of remote sensing satellite respect to the disaster area and high expenses of aerial photogrammetry. It is feasible and valuable for the investigation and assessment of environment and engineering disaster. This paper focuses on the real-time target monitoring and navigation with a GPS unit equipped on the balloon platform for remote sensing flying. It makes the balloon possible to follow a set course, including the adjustment of altitude according to the terrain. Some aspects of integrated development of GPS and Mapinfo are also presented. The implementation of this system provides a guarantee for the balloon's remote sensing flying.
Data fusion for multisensor images based on edge features
Author(s):
Jun Li;
Deren Li
Show Abstract
This paper presents a new image fusion scheme based on multi- resolution analysis of wavelet theory for multi-sensor images. An area-based maximum variance selection rule is used for feature selection of the wavelet planes at different scale. Experimental results including the fusion of black-white air- photo and Landsat TM images, Landsat TM and SAR images are presented in the paper. Compared with the IHS method, the proposed scheme provides more reliable and capable of adaptability for combining and preserving the benefit of both the high spatial information of high-resolution image and the essential spectral information of low-resolution multi- spectral images.
Applications of NOAA/AVHRR data on grassland monitoring
Author(s):
Quangong Chen;
Tiangang Liang;
Yuling Mao;
Yaxing Wei
Show Abstract
With rapidly growing populations and a dwindling resource base, monitoring grassland resource appears more important for decision-making and sustainable development in pasture. In the paper, methods of applying NOAA/AVHRR data to monitor grassland yield and carrying capacity were discussed in detail. To eliminate errors of the grassland yields at different time, average vegetation index images were erected, and a new rectified formula to calculate the Average Normalized Difference Vegetation Index (ANDVI) was constructed according to the characteristics of both NOAA/AVHRR data and grasslands in China. Based on ANDVI images, grassland yield gradation was defined, a general grassland yield forecast model was regressed out by analyzing relevant contribution of different landscapes to ANDVI, and a complete set of methods and procedures to monitor grassland yield and seasonal grassland carrying capacity was finally made. Results of the study indicated that NOAA/AVHRR data could be used in grassland classification, mapping, yield estimation and decision-making in large areas in China.
Use of remote sensing technique to predict earthquakes
Author(s):
Zuji Qiang;
Lingzhi Li;
Changgong Dian;
Min Xu;
Fengsha Ge
Show Abstract
This paper consists of two parts: one is the basic principle of the satellite thermal infrared increase temperature precursor. In trivially introduce 'Red Swelling' theory on earthquake genesis and 'Coupling Action' between the earth and atmosphere. Second part describes 2 events of successful earthquake prediction examples and characteristics of satellite thermal infrared increase temperature precursor.
Research on marine monitoring by 3S technology
Author(s):
Beijing He;
Jiang He;
Quanbao Yang
Show Abstract
Based on 3S technology and theory of GPS data platform, this paper deals with the technical aspects of the marine monitoring and ecological protection. The techniques include the marine GPS geodetic data platform, international coordinate system, marine plate movement, marine disaster, marine biological monitoring, marine resources exploration, marine meteorological observation, marine environmental protection, biological protection and reasonable use.
Cadastral data model established and perfected with 4S technology
Author(s):
Beijing He;
Jiang He;
Jianpeng He
Show Abstract
Considering China's social essential system and the actual case of the formation of cadastral information in urban and rural area, and based on the 4S technology and the theory and method of canton's GPS geodetic data bench developed by the authors, we thoroughly research on some correlative technical problems about establishing and perfecting all-level's microcosmic cadastral data model (called model in the following) once again. Such problems as the following are included: cadastral, feature and topographic information and its modality and expressing method, classifying and grading the model, coordinate system to be selected, data basis for the model, the collecting method and digitalization of information, database's structural model, mathematical model and the establishing technology of 3 or more dimensional model, dynamic monitoring of and the development and application of the model. Then, the domestic and overseas application prospect is revealed. It also has the tendency to intrude markets cooperated with 'data bench' technology or RS image maps' all-analysis digital surveying and mapping technology.
Dynamic monitoring for land resource in the Yangtze River Delta region
Author(s):
Jinfang Dai
Show Abstract
The land is the most important resource for the mankind. It has important significance for regional develop economic and plan decision to find out the situation and change trend of land resource in Yangtze River Delta region. Based on the techniques of remote sensing and GIS, the dynamic monitoring for land resource in Yangtze River Delta takes the multitemporal remote sensing imagines as the information source. Through the thematic information processing, classification and information extraction, it gets the multi- temporal maps of land resource. Depend on technique of GIS it realizes the overlay, reiterative and statistical analysis of the multi-temporal land resource information, makes the land resource dynamic maps and get the quantity. This paper described the method of remote sensing information processing, technical design, classification system and the change trend of the land resource in the dynamic monitoring.
Quantitative vegetation cover of Ordos region
Author(s):
Hongkang Chi
Show Abstract
Desertification has a close relationship with the sand vegetation cover in Ordos region. The dynamic monitoring to the sand vegetation cover using satellite data can provide useful information to understand the desertification in Ordos region. In this paper, we built the correlative model between the sand vegetation cover and the modified soil adjusted vegetation index (MSAVI) in Ordos region. Satellite data must be processed before these data are used in the correlative model. First, the atmospheric effects were corrected using the method of bare sand soil line. Then, the soil background effects were reduced using the MSAVI. The results of this study indicated that the maximum cover of the sand vegetation in Ordos region was 60%.
Space resection of SPOT image
Author(s):
Zhilong Wan;
Yu-Qi Huang
Show Abstract
There are two difficult points for the SPOT image data processing. The one is the calculation of its exterior elements between which there is strong correlation. The other is that the SPOT image has no epipolar line with strict sense, so the traditional epipolar correlation can not be applied actually. In this paper the Radio regression is presented to overcome their correlation and calculate the exterior elements. The results of from experiments show that the method is stable and with high accurate result. For the second problem this paper tested the matching scheme named 'anchor point,' which is a kind of two-dimensional matching method with multilayer control. Experiments show that it has the character of high speed and accurate.
Analysis of remote sensing data in thermal infrared waveband of geothermy in east Fujian province
Author(s):
Biru Ge
Show Abstract
This paper analyzes the geothermy in east Fujian province, applying the remote sensing data in thermal infrared wave-band (Ch4 10.5 - 11.5 micrometer) of meteorological satellite NOAA- 9. This region is 60,000 square kilometers. On the 101 I2S image processing system, the author processed the remote sensing information recorded in daytime of December 17 and at night of December 18, 1985 by the National Center of Meteorological Satellite from the NOAA-9(CH4) flew across the Fujian Province. The content of processing is: evaluating the maximum of gray level; extracting the information of close level slicing; scaling operation; pseudo-color slicing and pseudo-color image compositing, etc. A series of thermal islands of geothermy distribution images in which the temperature decreased by degrees were obtained by processing. Geographical distribution of thermal islands of geothermy tallies with the thermal springs known, controlled by EW trend and NE trend crustal structure. To the south of Xianyou- Zhangpin EW trend fault zone, the temperature of thermal islands of geothermy is higher than that to the north. Effected by Changle-Nanao NE trend deep fault zone, the thermal islands of geothermy show intermittent zone distribution along NE trend, and from southeast to northwest the temperature decreases by degrees. The thermal islands of geothermy with the highest temperature are located in Zhangpu, Yunxiao, Zhaoan and nearby areas, and here are the intruded rock and extrusion rock in these areas.
Practice in 35-mm air remote sensing and aerophotogrammetry
Author(s):
Yuezu Jiang;
Yangsheng Wang;
Chuan Du
Show Abstract
With the development of light or super light aircraft that is used as the airborne platform for 35 mm air remote sensing, the updating of cameras and the improvement of sensitive films, an increasingly complete foundation has been laid for 35 mm air remote sensing. Practices show that this technology combined with analytical plotter produced satisfactory precision, achieving a major breakthrough in photogrammetry. It can also be used for large-scale topographic mapping in an engineering area.
Application of remote sensing and GIS in farmland monitoring in Shanxi China
Author(s):
Yuliang Qiao;
Jiuliang Feng;
Buzhou Ma;
Zhiqing Liu
Show Abstract
This is an introduction to the study on monitoring farmland by using remote sensing and GIS in Shanxi, China. As a result, farmland in high, medium and low yield was distinguished and mapped at scale of 1:500000 for whole province; 1:100000 for Xingding Basin and 1:50000 for Dingxiang County. A monitoring system was established with support of RS, GIS and multi-media technology for classification, monitoring and utilization decision-making of farmland. It an be used in management of sustainable agriculture development in China. This study is a key project of The Scientific and Industry Technology Committee of National Defense. It was finished and appraised in 1997 with an achievement reaching at international advanced level.
Application of remote sensing and GIS to the assessment of bank stability in the Lower Yangtze River
Author(s):
Jiazhu Huang;
Guochun Ma
Show Abstract
A dynamic multi-temporal remote sensing analysis was applied to the riverbank migration since 50s from Nanjing to the mouth in the Yangtze River and a graphic database was developed. A dynamic analysis was also applied to the water depth using multi-temporal channel maps and a database of water depth of the Lower Yangtze River was also set up. The assessment of riverbank stability was made combined with researches of riverbed evolution, geology, geomorphology, and bank revetment projects based on GIS.
Remote sensing image features of XiaoLangou gold deposit, Micangshan area
Author(s):
Ganshun Wang;
Jisheng Wei;
Weizhong Tao;
Derong Chen
Show Abstract
In 1990, according to the interpretation of satellite images, that was proposed the gold deposit in Micangshan area is controlled by SN-shear zone by the first author of this paper. Now a middle gold deposit has been found in XaoLangou. Using TM 6/4, 7/4, 5/4 image, the previous-named 'amphibole diorite' is divided into quartz diorite ((delta) o23) and KangDing super-group, and considered that KangDing super-group is the oldest auteferous formation, irregular massive enclaves texture which show diffuse contact with the rockbody can be distinguished on satellite images (the enclaves are mainly migmatized plagioclase granulate, plagioclase amphibole, troudjemite and so on), and are inferred to be relicts of remitted Ar-Pt1 geobody. So it is considered that the rockbody is a s-type granite rockbody formed by the reworking of earlier crust; along several SN ductile-brittle fault zone with about 5 - 6 km length in intensively developed intense chloritization and solidification. They are expressed as light-blue color zone in TM 5/7 - 4/3 image, red, yellow alteration color patches on super imposed on SN and NE- striking (or latitudinal) fault structures, they infer beresitization (or felsitization) in middle period stage. It has been discovered that saccharoidal quartz and nugget- bearing quartzdikes had been formed during late period stage. In JERS-1 SAR image, ductile shear zone displayed bright thin lines or small patterns which are dense, almost parallel, discontinuous extending along a line. In the view of researches for metllogenic image features, had predicted metallogenic belt-ore deposit and has achieved good results.
Remote sensing investigation of cultivated land change in Yangtze Delta region
Author(s):
Bingbai Li;
Chunshen Yu;
Miaoling Zhang;
Shunlin Zhang
Show Abstract
It is a critical important task to find out cultivated land change quickly, as the sharply reducing of cultivated land use because of the rapid development of industry and agriculture in Yangtze Delta Region. It is satisfied well to investigate land use change with the technology of remote sensing. According to the method of view distinguishing of 'dynamic graph and point comparing,' cultivated land changes from 1992 to 1995 were investigated for every county in the region, using 1/100000 'TM' imagine data as an information source. The results showed that the cultivated land was decreased sharply as much as 61000 hectares for the region in three years. The mean changing rate was 10.8% per year. And in the three cities, Suzhou, Wuxi and Changzhou, the rates were as high as 15.6%/year. Among the decreased cultivated land, construction land was occupied as the part of 51.8 - 62%. In order to protect limited land resources, a dynamic measuring system of land use must be organized. According to the 'TM' imagine data, using the method of remote sensing measurement, a macro- dynamic change of cultivated land in the level of county can be measured rapidly. The precision can be as high as 90 - 95%. The fixed number of measuring years may be determined according to the dynamic change of cultivated land in the region. The measuring contents of dynamic land use may be expanded to classifying of agriculture, breeding, industry and fishing.
Applications of remote sensing in coastal engineering decision making
Author(s):
Caixing Yun;
Qing He;
Sihai Li
Show Abstract
The coast is a zone where frequent mankind activities and frail ecology environment coexist. The coastal erosion and accretion caused by the interactions between sea and land have great influence on the coast development. The problems concerned by the coastal engineering are the stability and change trend of shoreline and beach. In this paper, the authors, through some case studies and research achievements of coastal projects, further expound the functions and application prospects of remote sensing in the decision-making of coastal engineering, such as estuarine regulation, construction of the harbor and navigation channel, beach reclamation, and site selection of the sewage outfall in the power station and city, etc.
Appraisement of environment remote sensing method in mining area
Author(s):
Fengjie Yang;
Han Zhen;
Tao Jiang;
Liqing Lei;
Cailan Gong
Show Abstract
Coal mining is attached great importance by society as a key profession of environmental pollution. The monitor and protection of coal-mine environment is a developing profession in China. The sulfur dioxide, carbon dioxide, carbon monoxide and other waste gases, which are put out by the spontaneous combustion or weathering of gangue are an important pollution resource of atmosphere. The stack of gangue held down many farmlands. Smoke, coal dust and powder coal ash pollute the environment of mining area and surroundings though the affection of monsoon. The pH value of water which coal mine drained off is low, and the drinking, farming and animal husbandry water where it flowed are affected. The surface subsidence which mining caused is a typical destruction of ground environment. The people pay attention to remote sensing as a method of rapidly, cheaply regional environment investigation. The paper tires making an appraisement of mining area environment monitor by many kind methods of remote sensing from the characteristic of mining area environment.
Feasibility of estimating rice planting area of hilly region in southern China using remote sensing technique
Author(s):
Geying Lai;
Xingwei Yang
Show Abstract
The objective of the study (Zhejiang province as study area) was to estimate rice planting area of hilly region in southern part of China by remote sensing technique with NOAA/AVHRR data. The research contents mainly concerned contrast tests on practical approaches, both digital elevation model (DEM) and digital slope model (DSM) derived from the digital relief map were used for the purpose of improving the classification accuracy of AVHRR imagery in large-area hilly region. The results indicated that the accuracy of maximum-likelihood (MLH) classification could satisfy the professional requirements of estimating rice planting area and fuzzy supervised classification based on unmixing AVHRR imagery has better classification accuracy and stability than MLH. In addition, the results through using both DEM and DSM as ancillary categorization data suggests DSM may improve the results of extracting paddy field signatures from AVHRR, particularly may improve the spatial accuracy, while DEM contribute nothing to improve the accuracy mentioned above.
Investigation of geological environment using remote sensing techniques in the area of Yangtze River
Author(s):
Qinghua Yang;
Yong Zhang
Show Abstract
It's useful to economical development, environment protection, geological hazard prevention and cure that the study on environmental geology is conducted by remote sensing techniques in the area of Yangtze River. On basis of systematic investigation on geological data in environment, to obtain environmental information on geology and geography, the main measures include airborne and airspace remote sensing techniques, geological investigation, oceanic geological and geophysical exploration. The airborne color image is valid in determining landslide, mudflows, rockfall and other geological hazard. The scientific suggestions are achieved for recognition and remedy measures of environment geology in the studies area.
Relationship between GPR and population in urban residential plot based on remote sensing
Author(s):
Zhane Yin;
Jianggang Xu
Show Abstract
This paper discusses the progress of methods for estimating residential population in Shanghai. By using technology of remote sensing, sampling some spots for fieldwork, and supported by ER-Mapper and Mapinfo. We calculate GPR for each residential plot which is called residential community according to administrative division of Shanghai, then analyze the relationship between GPR and population, develop a linear regression model of GPR and population for sample communities. We hope this work could set a foundation for further application.
Remote sensing analysis of the Yarlung Zangbo suture zone in Xizang (Tibet) on orogenic movement of subduction and collision
Author(s):
Jianping Chen
Show Abstract
The authors extracted geological differences between the two blocks aside of the Yarlung Zangbo River, and some information about tectonic evolution of Yarlung Zangbo suture zone, which based on interpretation of remote sensing and statistical analysis. According to the research, the authors discussed the tectonic evolution of Yarlung Zanbo suture zone, which it can be divided into four stages. The first, the two blocks had each different evolution in geological history before they were matched. The second, the blocks were matched by orogenic movement of collision, which the dynamic direction was from south to north and formed some conjugate joints in NE and NW directions. The third, the monolithic region was ulteriorly forced, but the dynamic direction had a bit of change. At last, the tectonic movement became elevator tectonics in this region, which controlled modern model of river to be developed in E-W direction and topography.
Application of remote sensing data for prediction about gold mineral deposits in Northwest China
Author(s):
Yongjun Sun;
Hongzhou Guo
Show Abstract
This paper describes the application of remote sensing data, including TM images and color infrared airborne photographs, for predication about gold mineral deposits in Northwest part of China. Through TM image processing, we got a set of information enhanced TM images. Then all the information enhanced TM images and color infrared airborne photographs were comprehensively interpreted. It proved that the strata, intrusive igneous rocks, faults and folds and alteration zones could all be revealed. By analyzing the feature of image anomaly and gravity anomaly, we find a big fault zone and choose it as the field work area which was supposed to be the most favorable place for mineralization. Referring to the result of gold content of samples which were collected in field and image feature, we circled the target area of gold deposit on interpretation map. At last a prospecting model for this area was established.
Neural network application on land cover classification of China
Author(s):
Lin Zhu;
Ryutaro Tateishi;
Changyao Wang
Show Abstract
Land cover classification has long been primarily focused on automated image analysis applications and there is ongoing search for new classifiers that can yield improvements in results. This study shows the method of combining unsupervised classification and Artificial Neural Network (ANN) to the land cover classification of whole China and the time series National Oceanic and Atmospheric Administration (NOAA) advanced very high resolution radiometer (AVHRR) 1-kilometer (km) data is used. Some factors related to the effect on accuracy of land cover classification are discussed. The research involves the following steps: (1) Production of monthly maximum normalized difference vegetation index (NDVI). (2) Land cover classification system of China is proposed. (3) Unsupervised clustering of monthly NDVI data using ISOCLASS algorithm. (4) The preliminary identifying with the addition of digital elevation, ecoregions data and other land cover/vegetation reference data and extraction of the training data. (5) Land cover classification of China using Neural network. The results indicate that the accuracy of classification is much improved comparing with the common classification method.
Application of remote sensing technology for geological exploration in Mt. Kunlun area
Author(s):
Hongzhou Guo;
Yongjun Sun;
Qinghua Yong
Show Abstract
It is well known that the geological studies have not been carried out in detail in Mt. Kunlun, because it is difficult to study in field. For this reason, a study project with remote sensing method has been carried out in this area, a lot of useful information is extracted through image processing for Landsat TM (12 scenes) and Radarsat SAR data. By combining geology, geophysics, geochemistry and remote sensing data, we have divided regional geological structure units on the base of image feature of remote sensing. Analyzed geology conditions, summarized the relation of geological structure units and mineralizations and predicted the potential areas of exploration. In 1997, the geological studies in field have been carried out and verified the potential areas of exploration (especially for gold and copper deposits). It proved space remote sensing technology has great advantages in geological exploration of this kind area.
Variation of NDVI distribution under doubled CO2
Author(s):
Peng Du;
Liang Guo;
Qianguang Xiao;
Weiying Chen
Show Abstract
The variation tendency of NDVI distribution under doubled CO2 situation can be inferred from the study of the relationship between NDVI and relative meteorological factors and the forecast of NDVI distribution under such situation. First, nine models are respectively established to describe the relationships between NDVI and meteorological factors. Then these models are used to simulate the current NDVI distribution and to calculate the NDVI change under future- environmental conditions. The results showed that the NDVI value will stay or rise only a little in most part of China except Inner Mongolia and the tropic area in South China where the NDVI value will reduce by 1 to 4.
Advanced application of remote sensing technology in Qaidam Basin
Author(s):
Xiaoge Zhu;
Youyan Zhang;
Shihong Wang
Show Abstract
Qaidam basin is one of the major oil and gas-bearing basins in China, and is also the first basin of using remote sensing technology for geological exploration. Along with the fast development of petroleum industry into 1990s, remote sensing technology faced new challenges for the application in petroleum exploration field. Studies on advanced application of remote sensing technology has been carried out for the Basin and good results have been obtained.
Reveal the mystery of the Loulan ancient city's decline: one of the studies of remote sensing geology in Luobupo, Xinjiang
Author(s):
Yuhua He;
Yongjun Sun
Show Abstract
In accordance with remote sensing geology research on TM and MSS images, this paper indicates that being the only source of fresh water for Loulan City, the ancient Konque river was only one flowing through the Loulan area at that time. Being formed two barrier lakes, the blocked river cut off the source of water to this city because the upper reach of the river happened landslides twice early or late. The ancient city finally was abandoned for lack of supplying water until disappearance.
Ocean color satellite of China
Author(s):
Jianqiang Liu;
Zhouwen Yu
Show Abstract
The first Chinese Ocean Color Satellite (HaiYang-1) will be launched in 2000. The spacecraft will move and operate in a near sun-synchronous and near-polar orbit at altitude of 798 km. Installed on the satellite there are two sensors: one being 10 bands ocean color and temperature scanner with the spatial resolution of 1.1 km, the other being 4 bands CCD coastal zone imager with the spatial resolution of 250 m. The satellite is designed to detect some of the marine environmental parameters of the China Seas. It is believed that the satellite will play an important role in monitoring marine environment and coastal zone, and studying the global environmental changes.
Modeling lidar returns from vegetation canopies
Author(s):
Guoqing Sun;
K. Jon Ranson
Show Abstract
The Vegetation Canopy Lidar (VCL) is scheduled for launch in 2000 as the first mission of NASA's new Earth System Science Pathfinder Project. It will provide unique dataset on canopy geometry and sub-canopy topography, which will lead to improved understanding of important structures and processes of Earth environment. To understand the relation between canopy structure and the Lidar waveform, a 3-d model is implemented in this study. Various forest stands were used to parameterize this vegetation lidar waveform model including (1) simulated stands at various ages from forest growth model, (2) forest stand with detailed field measurements, and (3) simulated forest stands with different spatial tree distributions. The simulated lidar waveforms for various stands were presented and the results were discussed in this paper.
Climatology of the middle-atmosphere temperature from long-term lidar measurements at mid and low latitudes
Author(s):
I. Stuart McDermid;
Thierry Leblanc;
Philippe Keckhut;
Alain Hauchecorne;
Chiao Yao She;
David A. Krueger
Show Abstract
Long term measurements from several lidar instruments, located at 44.0 degrees N, 40.6 degrees N, 34.4 degrees N, and 19.5 degrees N, were used to develop a new climatology of the middle atmosphere temperature. For each instrument, the measurements on every day of the year over the entire record were averaged to build a composite year of temperature profiles. The lidar climatologies were compared to the CIRA-86 model which appears to be systematically too cold between 90 and 95 km, by greater than or equal to 20 K, and possibly 6 - 8 K too warm around 80 km, making its use as a reference questionable at these altitudes. The annual and semi-annual components of the seasonal variability and the 2- to 33-day period variability were also investigated. An annual cycle with 6 - 7 K amplitude in the upper stratosphere, increasing to 15 - 20 K at 80 km, is observed at mid-latitudes. At lower latitudes, a semiannual oscillation (SAO) propagates downward from 85 to 30 km and is characterized by a stronger first cycle than the second (4 K and 2 K amplitude). The 2- to 33- day variability at mid-latitudes shows a maximum during winter around 40 km and in the mesosphere. Finally, sudden seasonal transitions, highly consistent between all instruments, have been observed, in particular in the early winter mid-latitudes with a two-step warming of the mesosphere between 65 and 85 km.
Redesign and improved performance of the JPL-TMF tropospheric lidars
Author(s):
I. Stuart McDermid;
Georg Beyerle;
D. Haner;
T. Daniel Walsh
Show Abstract
We describe improvements to two lidar systems for measurements of ozone and aerosols in the troposphere and lower stratosphere. These changes are primarily related to the receiver optical sub-systems and the principal topics presented are the telescopes, the ozone DIAL receiver, and the aerosol lidar receiver. The data acquisition systems were also replaced. The goals of these modifications were to increase the spatial and temporal resolution of the lidars, to extend the altitude range covered, and to improve the quality of the raw data.
Compact scanning lidar systems using holographic optics
Author(s):
Geary K. Schwemmer;
Thomas D. Wilkerson;
David V. Guerra
Show Abstract
Two scanning lidar systems have been built using holographic optical elements (HOE) that function as a scanning telescope primary optic. One is a ground based lidar using a reflection HOE, and uses a frequency doubled Nd:YAG laser transmitter. The other system is an airborne/ground based system that uses a transmission HOE and operates at the 1064 nm fundamental of the Nd:YAG laser. Each HOE has a focal spot on the center- line, normal to the flat disk holding the hologram, and a field of view (FOV) that points approximately 45 degrees from the normal. Rotating the disk effects a conical scan of the FOV. In both systems, the same HOE is also used to collimate and steer the transmitted laser beam. The utility of using the HOEs to save weight and size in scanning lidars is evidenced by the atmospheric backscatter data collected with these systems. They also will lower the cost of commercial systems due to the low cost of replicating HOEs and the simplified mechanical scanning systems. Development of airborne scanning lidar altimeters and other lidars and passive instruments using holographic optics are underway, including the development of a one meter diameter, space qualified holographic scanning telescope for use in the ultraviolet.
Eye-safe all-solid state laser for coherent wind lidar in space
Author(s):
Jirong Yu;
Upendra N. Singh;
Norman P. Barnes;
James C. Barnes;
Mulugeta Petros;
Mark W. Phillips
Show Abstract
Global wind measurement is a key component of weather prediction. Coherent wind lidar provides excellent wind profile measurement sensitivity and accuracy through the use of heterodyne detection technique. A high pulse energy, high beam quality, very narrow linewidth laser is essential for successful coherent wind detection. We have developed an eye- safe all solid state Ho:Tm:YLF power oscillator with ring configuration to be used as coherent lidar transmitter. It achieved an optical to optical efficiency of 0.03. A Q- switched output energy as high as 109 mJ at 6 Hz, with a pulse width of 170 ns is obtained. The resonator alignment sensitivity, heat dissipation efficiency and polarization extinction ratio are all characterized for space application lidar. Laser performance as a function of laser rod temperature and pump intensity has also been investigated. The high power and high beam quality of this laser make it well suited for use as a coherent wind lidar transmitter on a space platform.
Lidar monitoring of anomalous aerosol concentration in the atmosphere from space
Author(s):
Gennadii G. Matvienko;
Vitalii S. Shamanaev;
Grigorii P. Kokhanenko;
Vladimir A. Alekseev
Show Abstract
As shown earlier by direct measurements, the spectrum of aerosol particles in the surface atmospheric layer is sharply changed before an earthquake. A lidar operating at two or three frequencies is capable to detect regions with anomalous aerosol composition with the help of a simple data processing algorithm. Such a lidar can be used as part of a global network on earthquake warning.
Validation of LITE-derived Saharan dust layer characteristics
Author(s):
V. Mohan Karyampudi;
Stephen P. Palm;
John A. Reagan;
Hui Fang;
William B. Grant;
Cyril Moulin;
H. F. Pierce;
Edward V. Browell;
Samuel Harvey Melfi
Show Abstract
Lidar observations from the Lidar-in Space Technology Experiment (LITE), in conjunction with European Center for Medium Range Weather Forecasting (ECMWF) and Meteosat data were used to examine the Saharan dust characteristics including its structure, evolution and optical depths over Western Africa and E. Atlantic regions. The lidar backscatter profiles reveal a complex structure of the dust layer but, in general, show a good agreement with the features depicted in the conceptual model of the dust plume. Optical depths of the Saharan dust layer derived from two independent methods were compared with those obtained from the Meteosat data. Although the LITE-derived optical depth patterns from the two methods are in good agreement with each other, they show some differences with those derived from the satellite data, particularly in the inference of heavy dust concentration over the E. Atlantic.
Analysis of liquid samples using laser-induced breakdown spectroscopy
Author(s):
Ota Samek;
Miroslav Liska;
Jozef Kaiser;
Vladislav Krzyzanek;
Helmut H. Telle;
Gavin W. Morris;
David C. S. Beddows
Show Abstract
The application of Laser Induced Breakdown Spectroscopy (LIBS) to real-time, in-situ and remote analysis of trace amounts in liquid samples is described, to be used for example in harsh or difficult-to-reach environments within industry for the analysis of pollutants in water. Numerous elements, including a range of toxic heavy metals, have been measured over a wide range of concentrations. Detection limits usually are in the range of a few parts per million; for several elements even lower limits could be realized. The analysis system is based on a fiber delivery assembly which is capable to both deliver the laser light to, and to collect the micro-plasma light from the target area, up to 30 m. Alternatively, a telescopic arrangement for in a 'line-of-sight' arrangement was employed. In order to provide quantitative data in the evaluation of laser generated plasmas, parameters such as electron densities, plasma temperature, line shape functions, and others need to be known; their measurement and determination are outlined. For internal standardization and the generation of concentration calibration curves, reference lines of carefully chosen elements were used.
Ozone and aerosol distributions in the Pacific as observed by NASA's airborne UV DIAL system
Author(s):
Carolyn F. Butler;
Edward V. Browell;
Marta A. Fenn;
William B. Grant;
Marian B. Clayton
Show Abstract
The NASA Langley Research Center's Airborne UV DIAL system has been flown on many tropospheric and stratospheric field campaigns since 1980. The current system, in its tropospheric configuration, transmits four beams in both nadir and zenith directions making measurements of O3 and aerosols from near the surface to above the tropopause. This system has been flown on the NASA DC-8 during the Global Tropospheric Experiments (GTE) to provide real-time remote sensing of tropopause heights, stratospheric intrusions, cloud tops/bases, boundary layer heights, and, in general, the large-scale variations of O3 and aerosol distributions across the troposphere. In addition, post-mission analyses of relative amounts of ozone O3 and aerosols as compared to discriminator profiles of each, permits an airmass characterization scheme including stratospherically influenced air, plumes with either high O3 or high aerosols or both, continental outflows, convective transport, and clean marine air. During the missions the DIAL instrument is routinely used to identify altitudes of O3 and/or aerosol layers so that the aircraft can then be directed to fly subsequent legs at specified heights to allow for in situ sampling of key species. In post-mission analyses the DIAL measurements provide the broader context for the in situ measurements of other trace species and, when coupled with meteorological and trajectory analyses, play a vital role in the interpretation of the dynamics and photochemistry of the troposphere. To date, NASA's GTE program has conducted three exploratory missions over the Pacific Ocean. PEM West-A (September-October 1991) and PEM West-B (February-March 1994) were focused in the western Pacific of the northern hemisphere to investigate the budget of O3 and its precursors and to assess both the natural and anthropogenic impact of key atmospheric trace species in this region. PEM West-A was staged in late summer/early fall when the airflow is dominated by easterly across the Pacific. The second phase, PEM West-B, was staged during late winter when the airflow is characterized by maximum outflow from the Asian continent. PEM Tropics-A (September-October 1994) involved two NASA aircraft in a study of the chemistry of the troposphere over the central and southern Pacific with a focus on the tropics in the southern hemisphere. The intent was to study one of the few remaining clean air regions of the world to better understand the role of nitrogen oxides in the O3 budget. A follow-up to this study, PEM Tropics-B, is in the process of being planned for February-- April 1999 in a contrasting meteorological regime. Selected O3 and aerosol distributions are illustrated from each of these field campaigns showing some of the key features in each experiment as observed by the airborne UV DIAL system.
Lidar probing the urban nocturnal boundary layer
Author(s):
T. M. Mok;
Kang Ming Leung;
Aaron HoPui Ho;
Johnny C. L. Chan;
Chung Tat Ng
Show Abstract
Lidar observations to study the nocturnal boundary layer in the atmosphere were made on selected evenings during December 1997 - March 1998 at the City University of Hong Kong (lat. 20 degree(s)20'6', long. 114 degree(s)10'18', at 57 m AMSL), Hong Kong. The ground-based Nd:YAG lidar has been operated to detect the vertical distribution of aerosols in the NBL at a subtropical urban site. It is shown that the vertical relative signal profiles can be employed to determine the heights of the single or multiple nocturnal inversions. In a clear sky and light wind evening transition period, the strong radiative cooling caused the air near the ground becomes stably stratified. The nocturnal inversion starts to emerge soon before sunset and grows vertically as the night progresses. The study also showed that the temporal evolution of the nocturnal inversion depth was rapidly increased soon after sunset and a slower rate in the midnight hours. The results of the study indicate that the vertical aerosol distribution in the multiple-layer is more complicated than that in the single-layer, of NBL. The early morning transition of the NBL is also discussed. A comparison of the lidar aerosol signals and radiosonde measurements was performed to evaluate the consistency of observations between the different systems.
Remote detection of the industrial nitrogen dioxide distribution by passive correlative spectrometer
Author(s):
Mickhail Shaikov
Show Abstract
The measurements of the NO2 vertical profiles in the 'Udachninsky' cavity by optical spectrometers using reflected solar radiation and artificial radiation source have be done. Simultaneously the measurements of the temperature profiles in this cavity just so have be done. There are the description of the optical spectrometer and methodology of measurement. It is suggested the possibility of avtomatical measurement of NO2 vertical profiles in the cavity.
Remote sensing of H2O at 0.94 um
Author(s):
Norman P. Barnes;
Brian M. Walsh
Show Abstract
An H2O vapor remote sensing instrument which could operate in the 0.94 micrometer region would have several highly desirable characteristics. Among the characteristics are access to absorption lines with approximately the correct strength and the availability of good detection systems. A good candidate for the laser for such a system is a Nd:garnet laser operating on one of the 4F3/2 to 4I9/2 transitions. To make such a system a reality, NASA Langley has investigated compositional tuning to develop a laser at precisely the correct wavelength and methods of improving the efficiency. Both efforts have achieved success. A flashlamp pumped Nd:YAG laser operating at room temperature on the 0.946 micrometer transition has achieved a threshold of 12 J and a slope efficiency of 0.009.
SPARCLE: a space-based mission to demonstrate global monitoring of tropospheric winds with a Doppler lidar
Author(s):
George David Emmitt
Show Abstract
NASA's New Millennium Program selected a Doppler Wind Lidar (DWL) using heterodyne detection for the EO-2 mission scheduled for launch in 2001. The SPAce Readiness of Coherent Lidar Experiment (SPARCLE) will involve a 100 mj, pulsed 2 micron laser and a 25 cm wedge scanner. This mission represents the first time a DWL will have flown in space to make tropospheric wind measurements. In addition to demonstrating that the technology can operate in a space environment, the SPARCLE will also provide data sets that are critical to the validation of system performance models and the selection of optimal scanning patterns required for future data products. Extensive computer simulations have been conducted for SPARCLE and some of the follow-on mission concepts that would lead to a fully operational instrument. Global weather forecasting models have been used to provide realistic representations of cloud, water vapor, winds and their effects on DWL data product accuracy and coverage. Results from these simulation efforts indicate that a Coherent DWL can be built and operated to provide virtually full tropospheric coverage, clouds permitting.
Prospects for long-term lidar cloud observations
Author(s):
C. Martin R. Platt
Show Abstract
Long-term observations of the atmosphere are required to understand the earth's climate and its variability. The utility of the long-term observations of clouds is explored in this paper. Several national and international experiments have shown that such observations are feasible, and the resultant scientific benefits make them desirable. Scientific requirements are discussed in terms comprehensive statistics of cloud amount, base height and depth, optical depth and microphysics, including cloud phase and effective radius. The instrumental requirements to measure the above quantities are described, indicating the increased instrumental sophistication that is required for the more detailed observations.
NASDA mission demonstration satellite lidar project and its sciences
Author(s):
Yasuhiro Sasano;
Kazuhiro Asai;
Nobuo Sugimoto;
Yasuaki Kawamura;
Kenji Tatsumi;
Tadashi Imai
Show Abstract
In the Mission Demonstration Satellite Lidar (MDS-lidar) Project, the National Space Development Agency of Japan (NASDA) has started development of a satellite-borne lidar system for experiments in space, which is called Experimental Lidar-In-Space Equipment (ELISE). Its main purposes are to demonstrate technical feasibility of a space-borne lidar and its key components, and also to get scientific data on clouds/aerosols distribution for better understanding of the earth climate system. Presentation will be made on the ELISE development plan, scientific goals and their implementation plan.
Tunable lidar system based on IR OPA laser source
Author(s):
Paolo F. Ambrico;
Aldo Amodeo;
Salvatore Amoruso;
Mario Armenante;
V. Berardi;
Antonella Boselli;
Riccardo Bruzzese;
Roberta Capobianco;
Gelsomina Pappalardo;
Nicola Spinelli;
Raffaele Velotta;
Xuan Wang
Show Abstract
A lidar system with the characteristic of simultaneously monitoring several atmospheric parameters such as atmospheric aerosols load, water vapor content, temperature and density, atmospheric transmissivity, and atmospheric pollutants concentration, has been realized. This system, based on two OPA lasers pumped by a Nd:YAG laser operating at maximum repetition rate of 100 Hz, is primary dedicated to tropospheric measurements. The system is continuously tunable over the spectral range 410 nm - 2500 nm, allowing DIAL measurements in a region where most of atmospheric pollutants display absorption lines. Preliminary measurements have been carried out. We report the simultaneous temporal evolution of the aerosol backscattering coefficient profiles at 355 nm and 829 nm in a rural area. A method to select optimal couples of wavelength for DIAL measurements in the near/mid IR spectral region has been developed. A sensitivity analysis has been carried out in order to find the minimum detectable concentration, that has been demonstrated of the order of few tenths up to few part per million in volume.
Mesospheric temperature inversions observed from long-term lidar measurements at mid and low latitudes
Author(s):
Thierry Leblanc;
I. Stuart McDermid;
Philippe Keckhut;
Alain Hauchecorne
Show Abstract
Results from new observations of mesospheric temperature inversion layers using long-term lidar measurements at mid- and low-latitudes are presented. Observations of inversions above Table Mountain, California, (34.4 degrees N) and Mauna Loa, Hawaii, (19.5 degrees N) are in very good agreement with previous lidar and satellite observations. At least two distinct types of events have been observed. The winter inversions occur near 70 km altitude at midlatitudes in December-January and about 1 - 2 months laster at subtropical latitudes. The tidal signature in the middle atmospheric thermal structure has been investigated using more than 140 hours of nighttime lidar measurements at TMF during January 1997 and February 1998. The temperature profiles (30 - 85 km) revealed the presence of persistent mesospheric inversions around 65 - 70 km altitude with a clear Local-Solar-Time (LST) dependence. Also, some higher altitude inversions (80 - 85 km) have been observed at lower latitudes around the equinoxes and 1 - 2 months later at mid-latitudes. In particular the temperature minimum systematically observed at the altitude of approximately 80 km and propagating downward throughout the night might also suggest the important role played by the tides.
Lidar observations of the middle-atmosphere thermal tides at Mauna Loa (19.5-deg.N): comparison with HRDI and GSWM
Author(s):
Thierry Leblanc;
I. Stuart McDermid;
David A. Ortland
Show Abstract
The tidal signature in the middle atmospheric thermal structure (15 - 95 km) at Mauna Loa, Hawaii, (19.5 degrees N) is investigated using more than 145 hours of nighttime lidar measurements obtained during October 3 - 16, 1996 and October 2 - 11, 1997. The daytime HRDI temperatures taken in September and October 1993 - 1997 and zonally averaged at the same latitude are also used. The nighttime lidar and daytime HRDI temperature evolution and tidal signatures are compared to the predictions of the GSWM tidal model. Agreement is found between lidar and GSWM below 60 km, and between HRDI and GSWM above 85 km. Some significant disagreement is found between 60 and 80 km altitude. In particular, a strong semidiurnal signature is observed by lidar and not predicted by GSWM. It appears that the tidal structure observed by lidar is more representative of that predicted by GSWM at 24 degrees N, suggesting a latitudinal shift between theory and observation. It is not clear whether this shift is related to an indetermination of the tidal source and/or propagation or if the observed differences are simply due to local/regional Local-Solar-Time-related oscillations obscuring the tidal signature.
Scanning lidar application for pollutant sources in an industrial complex
Author(s):
Shiv R. Pal;
Don Hlaing;
Allan I. Carswell;
Gilles Roy;
Christian Bastille
Show Abstract
This paper presents the results of a lidar campaign for aerosol and smoke plume studies carried out in collaboration with the Ministry of Environment of the Province of Ontario at the industrial complex in the city of Hamilton. The aim of the study was to apply lidar remote sensing to measure simultaneously emissions from different sources and determine the potential of lidar for tracking and differentiating plumes from various industrial processes. This study was carried out with the scanning lidar system of the Canadian Defense Research Establishment (1064 nm, 60 mJ, 100 Hz, dual polarization). The scanning lidar system was successful in providing coverage in azimuth ((phi) ) and elevation ((Theta) ) to map effluent plumes in 3-D from a range of over 5 km targeting major individual industrial sites. From 5 km range, for differentiating the plumes within one industrial complex, the highest resolutions (Delta) (phi) equals 0.05 degrees and (Delta) (Theta) equals 0.03 degrees available were necessary. To understand the dynamic behavior of plumes, time series scans were required which are a key to determining sources of Black Fallout and fugitive emissions that deposit particulate matter in the Hamilton area. Examples of relative plume strengths as demonstrated by the lidar are also discussed.
Airborne differential absorption lidar and its evolution to space
Author(s):
Edward V. Browell
Show Abstract
Airborne laser systems have been used for making remote measurements of ozone, water vapor, and aerosols in studies of many important atmospheric processes. Recent ozone and aerosol investigations have been conducted in the troposphere over western Pacific and in the stratosphere in the tropics and Arctic, and water vapor, aerosols, and cloud investigations have been conducted over land and water during daytime and nighttime conditions. Studies are also being conducted of future spaceborne laser systems for global investigations of ozone, water vapor, aerosols, and clouds.
Intercomparison of LITE tropospheric aerosol retrievals with a regional aerosol climate model
Author(s):
Raymond M. Hoff;
A. Vandermeer;
L. Spacek;
J. P. Blanchet;
C. Ro;
R. Vet;
P. Liu;
S.-L. Gong;
U. Lohmann;
L. A. Barrie
Show Abstract
Using data from the Lidar In-Space Technology Experiment (LITE), the authors examine the ability to detect urban and regional scale pollution signatures from space. LITE showed that over 50 urban areas could be detected worldwide and that one case off Taiwan could be quantitatively studied to estimate the mass flux of sulphate aerosol from the island. These results are now being used in a regional aerosol climate model, NARCM, to predict the aerosol budget in the northern hemisphere. Comparisons of LITE aerosol retrievals and the NARCM predictions are given.
Scandinavian polar stratospheric clouds aerosol characteristics retrieved from lidar data
Author(s):
Federico Fierli;
Francesco Cairo;
Alain Hauchecorne;
Alberto Adriani
Show Abstract
This paper is based on the analysis and the interpretation of groundbased lidar and balloonborne laser backscatter sonde measurements of Polar Stratospheric Clouds. A classification of the clouds will be made on the basis of the measured parameters. This classification is also reproduced by different temperatures and thermal histories of the sampled air masses. A Mie aerosol model is used to identify the physical meaning of the variation in the optical parameters for liquid particles. This model is also used for the retrieval of the size distribution of the aerosol. It will be compared with a different model, based on the color index computation and with particle counter measurements.
Measurement of cloud solar reflected radiance and extinction from space lidar
Author(s):
C. Martin R. Platt;
William H. Hunt;
David M. Winker;
Mark A. Vaughan
Show Abstract
A method of obtaining the reflected solar radiance from clouds with space lidar is described. The lidar telescope and detector are used effectively together as a visible radiometer at the lidar wavelength, the background signal on a lidar backscatter profile being proportional to the observed radiance in the lidar field of view. A DC-coupled output from the telescope detector is required for this method. The RMS background noise signal is also proportional to the observed radiance, where a DC-coupled detector is still effective. However, an AC-coupled detector could also be used. Both the methods are used here to measure the relative radiance along a part of one orbit of the Lidar In-Space Technology Experiment (LITE) on Space Shuttle Discovery. This orbit crossed over Typhoon Melissa where the cloud was optically thick and the reflectance at 532 nm was estimated by normalization at maximum values to previously observed GMS satellite values over similar clouds. Retrieval of the radiance from the internal lidar parameters is also being investigated. Some profiles of extinction coefficient below cloud top near the center of Melissa were also retrieved, showing an increase in extinction below cloud top to at least a depth of 1 km.
Double-edge molecular technique for Doppler lidar wind measurement
Author(s):
Cristina Flesia;
C. Laurence Korb
Show Abstract
The double-edge lidar technique for measuring the wind based upon using molecular backscatter is described. The technique uses two high spectral resolution edge filters which are located in the wings of the Rayleigh-Brillouin profile. This doubles the signal change per unit Doppler shift, the sensitivity, and gives nearly a factor of two improvement in measurement accuracy relative to the single edge technique. The use of a crossover region is described where the sensitivity of a molecular and aerosol-based measurement are equal. This desensitizes the molecular measurement to the effects of aerosol scattering over a frequency range of plus or minus 100 m/s. We give methods for correcting for short- term, shot to shot, frequency jitter and drift using a laser reference frequency measurement and methods for long-term frequency correction using a servo control system. The effects of Rayleigh-Brillouin scattering on the measurement are shown to be significant and are included in the analysis. Simulations for a conical scanning satellite-based lidar at 355 nm show an accuracy of 2 - 3 m/s for altitudes of 2 to 15 km for a 1 km vertical resolution, a satellite altitude of 400 km and a 200 km X 200 km spatial resolution. Results for recent wind measurements, which show an accuracy of 1 m/s up to an altitude of 10 km, are given.
Sodium temperature lidar system for measuring the Antarctic mesopause region at Syowa station in 1999, 2000, and 2001
Author(s):
Tsukasa Kitahara;
Takuya D. Kawahara;
Fumitoshi Kobayashi;
Yasunori Saito;
Akio Nomura
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We are planning to measure the Antarctic mesopause region by a sodium temperature lidar at Syowa station (69 degrees 00' S, 39 degrees 35' E) for three years, 1999 - 2001 as a part of the 5th Campaign of Japanese Antarctic Research Expedition (JARE 40 - 42). The objective of this campaign is to clarify the mechanism of energetic interaction between the lower thermosphere and the upper mesosphere through the mesopause region over Antarctica. Lidar measurements will be made cooperatively with a MF radar and a Fabry-Perot Doppler imager. The pulse laser tuned to the sodium D2 resonance line (589 nm) can be obtained by a sum frequency of two injection seeded Nd:YAG lasers (1064 nm and 1319 nm) with a narrow spectral width below 0.2 pm. The temperature measurement can be made by detecting the Doppler broadening of sodium D2 fluorescence spectrum by tuning laser wavelength alternately at two points of its spectrum. Scattered photons are collected by a Dall-Kirkham Cassegrain telescope of 0.5 m in diameter and detected in photoncounting mode with a gated photomultiplier tube (PMT). The photons are integrated with a range-gated multichannel scaler and processed with a personal computer. Daytime measurements will be made by using an extremely narrow band Faraday filter.
Bistatic imaging lidar measurements of aerosols, fogs, and clouds in the lower atmosphere
Author(s):
Jinming Lin;
Hidetsugu Mishima;
Takuya D. Kawahara;
Yasunori Saito;
Akio Nomura;
Kenji Yamaguchi;
Kimio Morikawa
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We have been developing a bistatic imaging lidar using a high sensitive CCD camera with an image intensifier as a high speed shutter for measuring spatial distributions of aerosols, fogs and clouds in the lower atmosphere at daytime as well as at nighttime. The bistatic imaging lidar was applied to two field observation campaigns. One was made cooperatively with a wind profiler and a radiosonde at Moriya (36 km north of Tokyo) for five days from May 26 to 30, 1997 and another cooperatively with a monostatic lidar at Hakuba alpine ski area of Nagano for 10 days from February 7 to 16, 1998 during the period of the 18th Winter Olympic Games in Japan. We report the results obtained at both campaigns and discuss the ability of this system in measuring the meteorological features of the local lower atmosphere under different conditions.
High-spectral-resolution lidar measurements of aerosols, clouds, and temperature at NIES
Author(s):
Zhaoyan Liu;
Ichiro Matsui;
Nobuo Sugimoto
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A high spectral resolution lidar (HSRL) using a narrow-band frequency-doubled Nd:YAG laser and an iodine absorption filter has been developed and used for the observations of aerosols, clouds and temperature profiles at NIES, Tsukuba since December 1997. Examples of the measurements of the cloud and aerosol scattering parameters with this lidar are given in the paper. The results show that the HSRL is capable to provide the quantitative retrieval of the aerosol/cloud scattering properties. This paper also presents the HSRL simultaneous measurements of stratospheric aerosol and temperature profile. Some preliminary results of the stratospheric aerosol and temperature observation at NIES are also given and discussed.
Spectral and time-resolved measurements of marine oil pollution by YAG laser fluorosensor
Author(s):
Susumu Yamagishi;
Kazuo Hitomi;
Hiroshi Yamanouchi
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This paper describes a compact imaging lidar system capable of detecting fluorescence of substances excited by the third harmonic generator of the YAG laser using CCD camera with gated image intensifier. The system mounted on a small airplane or ships will provide the spreading image of oil spills and classification of substances for clean-up operations. From image data of the water Raman scatters, we present a method to measure the extinction coefficients for the oil film thickness measurement. As the reference to interpret the data obtained in the field, the time-resolved fluorescence characteristics of fuel oils and industrial chemical substances were measured with a streak scope in the laboratory within the wavelength of 350 to 575 nm and with decay time up to 500 ns.
Lidar network observation of Asian dust (Kosa) in Japan
Author(s):
Toshiyuki Murayama;
Nobuo Sugimoto;
Ichiro Matsui;
Kimio Arao;
Kengo Iokibe;
Ryuji Koga;
Tetsu Sakai;
Yasuhiro Kubota;
Yasunori Saito;
Makoto Abo;
Naseru Hagiwara;
Hiroaki Kuze;
Naoki Kaneyasu;
Rouichi Imasu;
Kazuhiro Asai;
Kazuma Aoki
Show Abstract
We have organized a network campaign for the observation of Asian dust in the spring of 1997 and 1998 in Japan. Through the communication with electric mail, we have successfully observed Kosa events by lidar, sunphotometer, and particle counter, etc. These data must be useful to analyze the transport mechanism of Asian dust and validate the satellite observations.
Lidar observations of the stratospheric aerosols at Bandung, Indonesia
Author(s):
Kohei Mizutani;
Toshikasu Itabe;
Motoaki Yasui;
Tetsuo Aoki;
Tomohiro Nagai;
Toshifumi Fujimoto;
Masao Hirota;
Osamu Uchino;
Agus Nuryanto;
Sri Kaloka Prabotosari;
Saipul Hamdi
Show Abstract
We installed a lidar system for observations of the stratospheric aerosols at Bandung, Indonesia on November 1996. The system employed the second harmonic wavelength (532 nm) of Nd:YAG laser. We can measure scattering ratio and depolarization of 532 nm, and Raman scattering of N2 (607 nm). The system works well and the stratospheric aerosols were detected between 18 km and about 35 km. Cirrus clouds are always observed between 10 km and tropopause and area around tropopause is clear except for cloud-like structures. Integrated backscattering coefficient (IBC) of the stratospheric aerosols in 1997 is about 6 X 10-5sr-1 level and smaller than the value observed in mid-latitude, corresponding to the higher tropopause in the equatorial region. Variation of IBC at Bandung seems to be small. It is yet not clear whether current aerosol load is background level or not. We need more long period observations to discuss about seasonal, QBO, and long term variation of aerosol load.
Commercial applications of lidar: review and outlook
Author(s):
Stephen E. Moody
Show Abstract
The transition into 'real world' applications, and the accompanying development of commercial business opportunities and ventures, is an important part of the technology development process. We discuss the present state of lidar commercialization and deployment into these applications. We then go on to discuss the ways in which the research community can (and we believe should) affect this technology adoption process.
Monitoring of the atmospheric boundary layer with lidar, sun photometers, and filter sampling in Tokyo
Author(s):
Toshiyuki Murayama;
Naoki Kaneyasu;
Hiroki Kamataki;
Satori Otsuka;
Mamoru Furihata;
Naoto Iwasaka;
Tatsuro Tsukamoto
Show Abstract
Since the winter of 1995, we have routinely performed combined measurements with polarization lidar, sun-photometer, and filter-sampling. Such a so-called closer experiment is necessary and useful to cope with the variety of boundary- layer aerosols. The aims of the observation are as follows: (1) study of the dynamics of the atmospheric boundary layer (ABL) by lidar, (2) use of depolarization ratio measurement for the study of the ABL and the characterization of aerosols, (3) to clarify the relationship between depolarization ratio and chemical component of the aerosol in the ABL, (4) comparison between the optical thicknesses derived from the lidar and the sun-photometer measurements, (5) diurnal and seasonal changes of the above items, etc. We will present an overview of the study until now.
Self-aligning lidar system and its application
Author(s):
Xuan Wang;
Mario Armenante;
Roberta Capobianco;
Luca Fiorani;
Raffaele Velotta
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An accurate transmitter-receiver alignment of a lidar system is essential to obtain correct results. At same time, the effective telescope area can influence the lidar returning signal, especially at the low range. In order to solve this problem, a fast and precise automatic alignment and data correction lidar system is presented, based on an emission- detection overlap model and ray tracing method. Using it we can get an aligned and whole range corrected lidar signal. A centering precision of few mrad has been obtained through a dedicated software automatic controlling a gimbals-mounted mirror. In particular the correctness of the center and of its error has been determined. While through the effective telescope area correction, got the atmosphere parameter as low as 60 m from the telescope. This system has been used in single wavelength direct detection mode and in tunable two- wavelength DIAL measurement. They were respectively applied for continuous monitoring of tropospheric aerosols and continuous measurement of the NO2.
DIAL infrared lidar for monitoring of main pipelines and gas industry objects
Author(s):
Pavel G. Philippov;
Yu. A. Bakhirkin;
Victor N. Moiseev;
R. N. Pichtelev;
Sergey N. Gurkin;
I. A. Zhutchenko
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The development of a differential absorption lidar (DIAL) system in the mid-IR region for the detection and monitoring of light hydrocarbons is presented. Two lithium niobate optical parametric oscillators provided the signal and reference wavelengths. With the aid of a topographical target the system detected 0,4 ppm of propane and 0.1 ppm of methane in the atmosphere at a greater than 0,5 km range in the controlled release tests.
Thermovision method for aerial monitoring of main gas pipelines
Author(s):
Victor N. Moiseev;
Pavel G. Philippov;
Sergey N. Gurkin;
Eugeny V. Dedikov
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The present article is devoted to the description of only one part of laser-thermovision technique for light hydrocarbons leaks detection from main gas pipelines -- thermovision channel. Some basic background estimations of method and results of flight tests are presented.
Tropospheric ozone measurements at a mid-latitude site using the RTD DIAL technique
Author(s):
Michael H. Proffitt;
A. O. Langford
Show Abstract
Ozone concentrations vary considerably in the troposphere on all spatial and temporal scales. The study of tropospheric ozone variability and trends require highly accurate measurements over time scales from minutes to years. The NOAA Rapid Tunable Daylight (RTD) Differential Absorption Lidar (DIAL) system with its high temporal (2 minutes/profile) and spatial (less than or equal to 1 km vertical) resolution is particularly well suited for these studies. The 5 year data set from our mid-latitude site provides valuable information about the processes that contribute to the variability of tropospheric ozone on timescales from minutes to years.
Lidar monitoring of the stratosphere
Author(s):
Philippe Keckhut
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Laser beams can be used to probe the chemical composition and physical state of the stratosphere. These techniques appear as well adapted for a long-term monitoring. Measurement requirements and analyses usually applied have been reported. Three lidar techniques have been briefly described with a particular emphasis on bias and limitations. First observations of collocated temperature, ozone and wind profiles obtained at the Observatoire de Haute-Provence (France) have been presented.