Table of Contents

Symbols and Acronyms

1 Introduction

1.1 Imaging system nomenclature

1.2 System modeling

1.3 Sensitivity and resolution limits

1.4 Infrared imaging systems

1.5 Infrared imaging system modeling

1.6 Model inputs

1.7 References

2 IR Imaging System Evolution

2.1 Optics

2.2 Scanners

2.3 Detectors and coolers

      2.3.1 Detector classification

      2.3.2 Specific detectors

      2.3.3 Detector operation

2.4 Specific systems

      2.4.1 Line scanners

      2.4.2 Common module systems

      2.4.3 EOMUX systems

      2.4.4 EMUX systems

      2.4.5 Second-generation systems

      2.4.6 Staring array systems

      2.4.7 Third-generation systems

2.5 Field of view

      2.5.1 Fill factor

      2.5.2 Staring arrays

      2.5.3 Scanning arrays

2.6 References

3 Radiometry

3.1 Radiative transfer

3.2 Planck's blackbody law

3.3 Camera formula

      3.3.1 Scanning arrays

      3.3.2 Staring arrays

3.4 Point source

3.5 Photometry

3.6 Normalization

3.7 References

4 MTF Theory

4.1 Windows and filters

4.2 Spatial frequency

4.3 Linear filter theory

      4.3.1 The EO system as a linear system

      4.3.2 Cascading MTFs

4.4 Superposition applied to optical systems

4.5 Phase shifts

4.6 References

5 Common Module Systems

5.1 Optics OTF

      5.1.1 Diffraction-limited OTF

      5.1.2 Central obscuration

      5.1.3 Non-circular apertures

      5.1.4 Anamorphic optics

      5.1.5 Aberrations

      5.1.6 Defocused optics

5.2 Detectors

5.3 Motion

      5.3.1 Linear motion

      5.3.2 Sinusoidal motion

      5.3.3 Random motion (jitter)

      5.3.4 Nonlinear scan mirror movement

      5.3.5 Low-frequency motion

5.4 Electronic MTF

      5.4.1 Conversion: Electrical frequency to spatial frequency

      5.4.2 Detector time constant

      5.4.3 Amplifiers

      5.4.4 Electrical filters

5.5 LEDs

5.6 Visual optics

5.7 Eye response

      5.7.1 Conversion: Eye spatial frequency to spatial frequency

      5.7.2 Eye MTF

      5.7.3 Eye contrast threshold function (CTF)

5.8 Optical zoom

5.9 System design example: Random motion

5.10 References

6 EOMUX Systems

6.1 Vidicon

      6.1.1 Conversion: Vidicon lines to spatial frequency

      6.1.2 Vidicon MTF

6.2 Video amplifiers and filters

      6.2.1 Conversion: Video frequency to spatial frequency

      6.2.2 Boost circuitry

      6.2.3 Video amplifiers

6.3 CRT monitors

6.4 References

7 EMUX Systems

7.1 Detector

      7.1.1 TDI

      7.1.2 SPRITE detector

      7.1.3 Uncooled detectors

7.2 Conversion: Sampling frequency to spatial frequency

7.3 Conversion: Video sampling frequency to spatial frequency

7.4 Digital to analog data

      7.4.1 Sample-and-hold

      7.4.2 Post-reconstruction filter

7.5 References

8 Staring Array Systems

8.1 Transfer efficiency

8.2 Flat panel arrays

9 Line Scanners

9.1 Rectangular aperture

      9.1.1 Diffraction-limited OTF

      9.1.2 Defocus OTF

      9.1.3 Ground coverage

9.2 Scanner

9.3 Motion

9.4 Electronic MTF

9.5 AN/AAD-5 CRT MTF

9.6 AN/AAD-5 film

      9.6.1 Conversion: Film response to spatial frequency

      9.6.2 Film MTF

9.7 References

10 Two-Dimensional MTF

10.1 Optics

10.2 Motion

      10.2.1 Linear motion

      10.2.2 Sinusoidal motion

      10.2.3 Random motion

10.3 Detector

10.4 Electronics

10.5 Digital processing

10.6 Visual optics

10.7 Vidicon

10.8 Displays

10.9 The eye

10.7 References

11 Sampling

11.1 Sampling theory

11.2 Horizontal sampling frequency

      11.2.1 Scanning systems

      11.2.2 Staring arrays

11.3 Vertical sampling frequency

      11.3.1 Scanning systems

      11.3.2 Staring systems

11.4 Reconstruction

      11.4.1 CRT monitor

      11.4.2 Flat-panel display

11.5 Fλ/d

11.6 Microscan

11.7 Super-resolution reconstruction

11.8 Sample-scene phase

11.9 Spurious response

      11.9.1 Schade's approach

      11.9.2 MTF squeeze

      11.9.3 Resolved cycle contraction

11.10 References

12 Imaging Processing

12.1 z-transform

12.2 Digital filters

      12.2.1 Boost filter

      12.2.2 Averaging filter

12.3 Electronic zoom (interpolation)

      12.3.1 Ideal interpolator

      12.3.2 Lanczos interpolator

      12.3.3 Pixel replication

      12.3.4 Linear interpolation

      12.3.5 Bilinear interpolation

      12.3.6 Image quality

12.4 Line-to-line interpolation

12.5 Noise reduction algorithms

12.6 Image restoration

12.7 References

13 Resolution

13.1 Analog metrics

13.2 NIIRS

13.3 Sampled data systems

13.4 Schade's equivalent resolution

      13.4.1 Analog systems

      13.4.2 Sampled data systems

13.5 References

14 Image Quality

14.1 Mathematical metrics

14.2 MTF

14.3 Perceived resolution

14.4 Subjective quality factor

14.5 MTFA

14.6 Square-root integral

14.7 Targeting task performance

14.8 Resolution versus perceivalbe detail

14.9 References

15 Atmospheric Transmittance

15.1 Atmospheric constituents

      15.1.1 Water vapor

      15.1.2 Aerosols

15.2 Visibility

      15.2.1 Meteorological range

      15.2.2 Contrast transmittance

15.3 LOWTRAN, MODTRAN, and HITRAN

15.4 Spectrally averaged atmospheric transmittance

15.5 Weather conditions

      15.5.1 Average conditions

      15.5.2 Probability of occurrence

      15.5.3 Naval model

      15.5.4 Land-based systems, horizontal path

      15.5.5 Land-based systems, slant path

15.6 MWIR versus LWIR

15.7 Sun glints

15.8 Solar scattering

15.9 Battlefield obscurants

15.10 References

16 Atmospheric MTF

16.1 C_N²

16.2 Fried's coherence diameter

      16.2.1 Horizontal path length

      16.2.2 Slant path

16.3 Turbulence MTF

16.4 Aerosol MTF

16.5 References

17 Target Signatures

17.1 What is ΔT?

17.2 300K models

17.3 Area-weighted ΔT

17.4 Thermal structure metrics

17.5 Diurnal variations

      17.5.1 Solar heating

      17.5.2 ΔT cumulative probability

      17.5.3 Environmental modifiers

17.6 Active targets

      17.6.1 Fuel combustion

      17.6.2 Frictional heat

17.7 Typical ΔTs

17.8 Target signature modeling

17.9 Sky background

17.10 Target signatures in the visible

17.11 Path radiance

      17.11.1 Infrared path radiance

      17.11.2 Visible path radiance

17.12 References

18 Sensitivity and Noise

18.1 Noise equivalent bandwidth

18.2 Scanning arrays (analog system)

      18.2.1 Photon noise

      18.2.2 Johnson noise

      18.2.3 Amplifier noise

18.3 Staring arrays

      18.3.1 Shot noise

      18.3.2 Dark current

      18.3.3 Fixed pattern noise

      18.3.4 Multiplexer noise

      18.3.5 Quantization noise

18.4 Detector responsitivity

      18.4.1 Classical semiconductors

      18.4.2 Novel semiconductors

      18.4.3 Thermal detectors

18.5 Specific detectivity

      18.5.1 BLIP

      18.5.2 Johnson noise limited

      18.5.3 D*_BB to D*_p conversion

      18.5.4 D*₃₀₀

      18.5.5 Focal ratio

18.6 System SNR

18.7 NEDT

      18.7.1 Scanning systems

      18.7.2 Staring arrays

      18.7.3 Uncooled systems

      18.7.4 Background temperature

      18.7.5 Variable integration time

18.8 Real systems

      18.8.1 Three-dimensional noise model

      18.8.2 Fixed pattern noise

      18.8.3 Noise figure

      18.8.4 Non-scene photons

18.9 Signal-to-noise optimization

18.10 300K models

18.11 NEI

18.12 References

19 System Performance Models

19.1 1975 NVL model

19.2 FLIR92

      19.2.1 FLIR92 theory

      19.2.2 Moderate aspect ratio targets

      19.2.3 SNR_TH and t_E

      19.2.4 Frame integration

      19.2.5 Head movement

      19.2.6 Embedded 1975 NVL model

      19.2.7 Two-dimensional MRT

      19.2.8 The brick wall

19.3 NVTherm Sept 2002

19.4 NVThermIP

19.5 TRM3

19.7 Model comparisons

19.8 References

20 Target Discrimination

20.1 One-dimensional target acquisition

      20.1.1 Johnson criteria

      20.1.2 Extended discrimination

      20.1.3 Target transfer probability function

20.2 Two-dimensional discrimination

      20.2.1 Discrimination requirements

      20.2.2 Two-dimensional TTPF

      20.2.3 Targeting task performance

20.3 Current definitions

20.4 Current N₅₀/V₅₀ values

20.5 Hot spot detection

20.6 Clutter

20.7 References

21 Range Predictions

20.1 ACQUIRE

      21.1.1 Range prediction methodology

      21.1.2 Range performance probability

      21.1.3 Two fields of view

21.2 Trade-off analyses

      21.2.1 Line-of-sight stabilization

      21.2.2 Resolution versus sensitivity

      21.2.3 STADIUM FLIR

21.3 NVThermIP

      21.3.1 Viewing distance

      21.3.2 Electric zoom

      21.3.3 Scene contrast

      21.3.4 Frame averaging

      21.3.5 Image enhancement

      21.3.6 Super-resolution reconstruction

21.4 Simplified range predictions

      21.4.1 Trade-off analyses

      21.4.2 Detector-limited systems

21.5 Pixels versus cycles

21.6 Pixels on target

21.7 300K models

21.8 Search

21.9 GIQE/NIIRS

21.10 References

Appendix 1 (Focal ratio)

Appendix 2 (Cosine^Nθ)

Appendix 3 (Central limit theorem)

Index