Table of Contents

1. INTRODUCTION 1

1.1 Solid state detectors 2

1.2 Imaging system applications 3

1.2.1 General imagery 6

1.2.2 Machine vision 7

1.2.3 Scientific applications 7

1.2.4 Military applications 8

1.3 Configurations 8

1.4 Image quality 11

1.5 Pixels, datels, disels, and resels 13

1.6 References 15

2. RADIOMETRY AND PHOTOMETRY 17

2.1 Radiative transfer 17

2.2 Planck's blackbody law 19

2.3 Photometry 21

2.3.1 Units 23

2.3.2 Typical illumination levels 25

2.4 Sources 26

2.4.1 Calibration sources 26

2.4.2 Real sources 27

2.5 Point sources and extended sources 30

2.6 Camera formula 31

2.7 Normalization 35

2.8 Normalization issues 38

2.9 References 42

3. CCD FUNDAMENTALS 43

3.1 Photodetection 44

3.1.1 Photogate 45

3.1.2 Photodiode 45

3.2 CCD array operation 45

3.3 CCD array architecture 54

3.3.1 Linear arrays 55

3.3.2 Full frame arrays 56

3.3.3 Frame transfer 57

3.3.4 Interline transfer 59

3.3.5 Progressive scan 64

3.3.6 Time delay and integration 66

3.3.7 Super CCD 70

3.4 Charge conversion (output structure) 71

3.5 Correlated double sampling 72

3.6 Antibloom drain 74

3.7 Low light level devices 77

3.7.1 Intensified CCDs (ICCD) 77

3.7.2 Electron bombarded CCD (EBCCD) 80

3.7.3 Electron multiplying CCD (EMCCD) 80

3.8 Charge injection device (CID) 82

3.9 References 84

4. CMOS FUNDAMENTALS 86

4.1 CCD and CMOS arrays: key differences 87

4.1.1 CCD array characteristics 87

4.1.2 CMOS array characteristics 89

4.2 CMOS arrays: prediction and reality 90

4.2.1 Smaller pixel potential limitations 91

4.2.2 Small pixel design evolution 93

4.3 Pixel electronics 94

4.3.1 3T CMOS pixel family 95

4.3.2 3T rolling shutter 98

4.3.3 4T, 5T, AND 6T CMOS pixels 99

4.3.4 Snapshot or simultaneous and global shutter readout mode 101

4.4 CMOS architectures 102

4.5 CMOS future 104

4.6 References 108

5. ARRAY PARAMETERS 110

5.1 Well capacity 110

5.2 Number of detectors 110

5.3 Dark pixels 112

5.4 Video chip size - optical format 114

5.5 Microlenses 116

5.6 Color filter arrays 118

5.7 Defects 121

5.8 References 122

6. ARRAY PERFORMANCE 123

6.1 Quantum efficiency 124

6.1.1 CCDs, CMOS, and EMCCDs 125

6.1.2 ICCD and EBCCD 135

6.2 Responsivity 136

6.2.1 CCD, CMOS, and EMCCD 137

6.2.2 Super CCD 145

6.2.3 ICCD and EBCCD 145

6.3 Dark current 147

6.4 Maximum signal 150

6.5 Noise 151

6.5.1 Shot noise 154

6.5.2 Reset noise 155

6.5.3 On-chip amplifier noise 155

6.5.4 Off-chip amplifier noise 157

6.5.5 Quantization noise 157

6.5.6 Pattern noise 158

6.5.7 Super CCD noise 160

6.5.8 EMCCD noise 161

6.5.9 ICCD noise 163

6.6 Dynamic range 164

6.7 Photon transfer and mean-variance 166

6.8 Array signal-to-noise ratio 171

6.8.1 CCD, CMOS, and Super CCD SNR 171

6.8.2 EMCCD SNR 173

6.8.3 ICCD SNR 174

6.9 Noise equivalent inputs 176

6.10 Lux transfer 178

6.11 Speed - ISO 185

6.12 References 186

7. CAMERA DESIGN 189

7.1 Camera operation 190

7.2 Optical design 191

7.3 Analog-to-digital converters 191

7.4 Image processing 193

7.4.1 The knee 193

7.4.2 Aperture correction 194

7.4.3 Color correction 194

7.4.4 Gamma correction 197

7.5 Video formats 199

7.5.1 "Conventional" video timing 201

7.5.2 Digital television 203

7.6 CRT overview 204

7.6.1 Monochrome displays 205

7.6.2 Color displays 206

7.7 Flat panel displays 208

7.8 Computer interface 209

7.9 References 209

8. LINEAR SYSTEM THEORY 211

8.1 Linear system theory 212

8.1.1 Time varying signals 212

8.1.2 Spatially varying signals 215

8.2 Electronic imaging system 216

8.3 MTF and PTF interpretation 217

8.4 Superposition applied to optical systems 219

9. MTF 222

9.1 Frequency domains 223

9.2 Optics MTF 226

9.3 Detectors 229

9.3.1 Rectangular 230

9.3.2 Circular 232

9.3.3 L-shaped 233

9.3.4 Notched Rectangle 233

9.4 Diffusion MTF 235

9.4.1 Bulk diffusion 235

9.4.2 Surface lateral diffusion 236

9.4.3 Epitaxial layer diffusion 237

9.6 Charge transfer efficiency 240

9.7 TDI 244

9.8 Motion 247

9.8.1 Linear motion 247

9.8.2 Random motion (jitter) 249

9.9 Electronic filters 252

9.9.1 Anti-alias analog filter 252

9.9.2 Digital filters 253

9.9.3 Sample-and-hold 257

9.9.4 Post-reconstruction filter 258

9.9.5 Boost 259

9.10 CRT display 260

9.10.1 Addressability 263

9.10.2 Character recognition 267

9.10.3 Display MTF 270

9.11 Flat panel displays 271

9.12 Printer MTF 272

9.13 The observer 273

9.14 Intensified CCD 275

9.15 References 277

10. SAMPLING 279

10.1 Sampling theorem 281

10.2 Aliasing 284

10.3 Array Nyquist frequency 286

10.3.1 Monochrome 286

10.3.2 CFA 288

10.3.3 Super CCD 288

10.4 Optical low pass filter (OLPF) 290

10.5 Reconstruction 293

10.6 Image distortion 296

10.7 Sampling "MTF" 298

10.8 Spurious response 299

10.9 Multiple samplers 302

10.10 References 303

11. IMAGE QUALITY 305

11.1 Resolution metrics 307

11.2 Optical resolution 309

11.3 Detector resolution 310

11.4 Electrical resolution metric 311

11.5 MTF-based resolution 312

11.5.1 Limiting resolution 312

11.5.2 Optics-detector subsystem 313

11.5.3 Schade's equivalent resolution 318

11.6 Display resolution 320

11.6.1 Disels 320

11.6.2 TV resolution 323

11.6.3 Flat panel displays 324

11.6.4 Printers 324

11.7 Observer-based resolution 325

11.7.1 MTFA 325

11.7.2 Subjective quality factor 326

11.7.3 Square-root integral 328

11.7.4 Targeting task performance 329

11.8 Viewing distance 330

11.9 Image reconstruction 334

11.10 References 336

12. RANGE PERFORMANCE 338

12.1 Atmospheric transmittance 338

12.2 Target contrast 340

12.3 Contrast transmittance 340

12.4 Range predictions 342

12.5 References 345

APPENDIX 347

f-number 347

INDEX 349