Preface ......................................................... x
Acknowledgements .............................................. xii
1 Introduction ................................................. 1
1.1 Key concepts ............................................ 4
2 Remote sensing basics ........................................ 6
2.1 Electromagnetic waves ................................... 6
2.2 The electromagnetic spectrum ............................ 8
2.3 Reflectance and radiance ................................ 8
2.4 Atmospheric effects .................................... 11
2.5 Multispectral feature recognition ...................... 13
2.6 Resolution requirements ................................ 14
2.7 Key concepts ........................................... 16
3 Remote sensors and systems .................................. 18
3.1 Introduction ........................................... 18
3.2 Remote sensors ......................................... 19
3.2.1 Multispectral satellite sensors ................. 19
3.2.2 Digital aerial cameras .......................... 20
3.2.3 Thermal infrared sensors ........................ 22
3.2.4 Radar and microwave radiometers ................. 23
3.2.5 Laser profilers ................................. 26
3.3 Remote sensing platforms ............................... 26
3.3.1 Airborne platforms .............................. 27
3.3.2 Medium-resolution satellites .................... 28
3.3.3 High-resolution satellites ...................... 30
3.3.4 Global observation satellites ................... 32
3.4 The NASA Earth observing system ........................ 33
3.5 Global Earth observation systems ....................... 34
3.5.1 Global Climate Observing System ................. 34
3.5.2 Global Earth Observation System of Systems ...... 34
3.5.3 Integrated Ocean Observing System ............... 35
3.6 Existing image archives ................................ 36
3.7 Key concepts ........................................... 38
4 Digital image analysis ...................................... 40
4.1 Image data format ...................................... 40
4.2 Image pre-processing ................................... 41
4.3 Image enhancement and interpretation ................... 42
4.4 Image classification ................................... 44
4.5 Image band selection ................................... 48
4.6 Error assessment ....................................... 49
4.7 Time-series analysis and change detection .............. 50
4.8 Field sampling using GPS ............................... 56
4.9 Use of Geographic Information Systems .................. 58
4.10 Key concepts ........................................... 62
5 Monitoring changes in global vegetation cover ............... 63
5.1 EM spectrum of vegetation .............................. 63
5.2 Vegetation indices ..................................... 64
5.3 Biophysical properties and processes of vegetation ..... 68
5.4 Classification systems ................................. 71
5.5 Global vegetation and land cover mapping programmes .... 73
5.5.1 NASA Pathfinder global monitoring project ....... 74
5.5.2 International geosphere-biosphere program ....... 75
5.5.3 Application of new satellites and radar ......... 76
5.6 Remote sensing of vegetation as a monitor for global
change ................................................. 77
CASE STUDY: Desertification in the African Sahel ....... 77
CASE STUDY: Deforestation of Amazonia .................. 80
5.7 Remote sensing of wetlands change ...................... 82
5.8 Fire detection ......................................... 87
5.9 Key concepts ........................................... 89
6 Remote sensing of urban environments ........................ 91
6.1 Urbanization ........................................... 91
6.2 Urban remote sensing ................................... 93
6.2.1 Three-dimensional urban model generation ........ 98
6.2.2 Stereo imaging .................................. 98
6.2.3 LiDAR ........................................... 99
6.2.4 Synthetic Aperture Radar (SAR) ................. 100
6.3 Microwave sensing of subsidence ....................... 104
6.4 Textural metrics ...................................... 108
6.5 Monitoring city growth ................................ 111
6.6 Assessing the ecology of cities ....................... 113
6.7 Urban climatology ..................................... 114
6.8 Air quality and air pollution ......................... 116
6.9 Climate change as a threat to urbanization ............ 120
6.10 Key concepts .......................................... 121
7 Surface and ground water resources ......................... 122
7.1 Remote sensing of inland water quality ................ 124
7.2 Remote sensing sediment load and pollution of inland
waters ................................................ 126
7.3 Remote sensing non-coastal flooding ................... 129
7.4 Bathymetry of inland waters ........................... 131
7.5 Mapping watersheds at the regional scale .............. 132
7.6 Remote sensing of land surface moisture ............... 135
7.7 Remote sensing of groundwater ......................... 137
7.8 Key concepts .......................................... 140
8 Coral reefs, carbon and climate ............................ 142
8.1 Introduction .......................................... 142
8.2 The status of the world's reefs ....................... 145
8.3 Remote sensing of coral reefs ......................... 146
8.4 Light, corals and water ............................... 148
8.4.1 Light and the water surface .................... 148
8.4.2 Light and the water body ....................... 152
8.4.3 Reflectance models for optically shallow
waters ......................................... 154
8.4.4 Reflectance signatures of reef substrata ....... 156
8.5 Passive optical sensing ............................... 159
8.6 Sensor-down versus reef-up sensing .................... 164
8.7 Spectral unmixing ..................................... 165
8.8 Image-derived bathymetry .............................. 167
8.9 LiDAR ................................................. 168
8.10 Sonar ................................................. 170
8.11 Sub-bottom acoustic profiling ......................... 174
8.12 Radar applications .................................... 177
8.13 Class assemblages and the minimum mapping unit ........ 178
8.14 Change detection ...................................... 180
8.15 Key concepts .......................................... 183
9 Coastal impact of storm surges and sea level rise .......... 184
9.1 Predicting and monitoring coastal flooding ............ 186
9.2 Coastal currents and waves ............................ 191
9.3 Mapping beach topography .............................. 193
9.4 LiDAR bathymetry ...................................... 196
CASE STUDY: LiDAR application to modelling sea level rise
at the Blackwater National Wildlife Refuge ................. 200
9.5 Key concepts .......................................... 202
10 Observing the oceans ....................................... 204
10.1 Introduction .......................................... 204
10.2 Ocean colour, chlorophyll and productivity ............ 205
10.3 Hazardous algal blooms and other pollutants ........... 210
10.4 Sea surface temperature ............................... 213
CASE STUDY: Upwelling and El Niño ..................... 217
10.5 Ocean salinity ........................................ 220
10.6 Physical ocean features ............................... 223
10.6.1 Sea surface elevation and ocean currents ....... 224
10.6.2 Sea surface winds .............................. 229
10.6.3 Ocean waves .................................... 231
10.6.4 Oil slicks and other surface features .......... 232
10.6.1 Ocean observing Systems ........................ 236
10.8 Marine GIS ............................................ 237
10.9 Key concepts .......................................... 239
11 Monitoring Earth's atmosphere .............................. 241
11.1 The status of Earth's atmosphere ...................... 241
11.2 Atmospheric remote sensing ............................ 243
11.3 The 'A-Train' satellite constellation ................. 244
11.3.1 Dancing on the A-Train ......................... 246
11.4 Remote sensing atmospheric temperature ................ 246
11.5 Atmospheric remote sensing of ozone ................... 249
11.6 Atmospheric remote sensing of carbon dioxide .......... 252
11.7 Remote sensing atmospheric dust ....................... 258
CASE STUDY: Spaceborne monitoring of African dust
events ................................................ 259
11.8 Clouds ................................................ 262
11.9 Forecasting Earth's atmosphere ........................ 263
11.10 Atmospheric models and reality ....................... 263
11.11 Hurricanes ........................................... 265
CASE STUDY: Hurricane Katrina.......................... 267
11.12 Key concepts ......................................... 270
12 Observing the cryosphere ................................... 272
12.1 Introduction .......................................... 272
12.2 The history and status of the polar ice sheets ........ 272
12.3 Ice and sea level ..................................... 274
12.4 Ice and climate ....................................... 275
12.5 Present ice loss in context ........................... 277
12.6 Remote sensing of the Earth's ice sheets .............. 278
12.6.1 Passive optical and thermal remote sensing ..... 278
12.6.2 Passive microwave remote sensing ............... 279
12.6.3 Active microwave remote sensing ................ 281
12.6.4 Active optical remote sensing - ICESat ......... 284
12.7 Ice sheet mass balance ................................ 287
CASE STUDY: Disintegration of the Larsen and Wilkins
ice shelves ........................................... 288
12.8 Remote sensing permafrost ............................. 290
12.9 Key concepts .......................................... 294
13 Effective communication of global change information
using remote sensing ....................................... 296
13.1 Global environmental change as an interdisciplinary
issue ................................................. 297
13.2 Effective communication through accessibility of
data .................................................. 299
14 Looking ahead: future developments ......................... 303
14.1 Emerging technologies ................................. 303
14.1.1 Fusion in remote sensing ....................... 303
14.1.2 Hyper-spatial satellites ....................... 304
14.1.3 Hyperspectral hyper-spatial satellites ......... 306
14.2 The near future ....................................... 307
14.3 The more distant future ............................... 310
14.4 Advanced image analysis techniques .................... 310
14.5 Looking ahead at a changing Earth ..................... 311
References ................................................. 316
Index ......................................................... 361
This book has a companion website: www.wiley.com/go/purkis/remote
|