CHAPTERS
Satellite Microwave Radar Observations of Antarctic Sea Ice
M.R. DRINKWATER
Contents
8.1 Introduction...................................................................................... 146
8.2 Obtaining Spaceborne Radar Data in Antarctica..................................... 147
8.2.1 Antarctic SAR Data................. ................................... ....................... 147
8.2.1.1 ERS-l and ERS-2 SAR...................................................................... 147
8.2.1.2 J-ERS-l SAR .................................................................................. 147
8.2.1.3 RADARSAT SAR ............................................................................ 148
8.2.1.4 ERS SAR Backscatter Calibration Accuracy........................................ 148
8.2.2 Antarctic SAR Receiving Stations....................................................... 149
8.2.3 Scatterometer Imaging........................ ......... .... ....... .... ....... ....... ........ 150
8.3 Sampling Issues.................................................................................. 150
8.3.1 Temporal and Spatial Coverage.... .................... ...................... ............. 150
8.3.2 Filling the Gaps................................................................................
151
8.4 Ice Classification Issues ......................... ............... .............. ........... ......
151
8.4.1 Backscatter Characteristics of Antarctic Ice.......................... ................ 152
841.1 Shipborne Scatterometer Signatures .......... ....................................... 152
8.4.1.2 Regional Winter C-band Backscatter Variability.......... ....................... 157
8.4.1.3 Snapshot Signature Summary.......................................................... 161
8.4.2 The Future of Ice Classification.......................................................... 163
8.4.2.1 Scatterometer Ice Classification....................................................... 163
842.2 Multichannel and Multisensor Data Fusion....................................... 165
8.5 Antarctic Sea Ice Dynamics.................................................................. 165
8.5.1 Length Scales of Antarctic Sea-Ice Drift ............................................... 165
8.5.1.1 Coastal Regime .... ......................... .................... .................... ......... 166
8.5.1.2 Central Basin................................................................................. 166
8.5.2 Motion Spectra and Temporal Covariance with Wind.. ................ .......... 167
8.5.2.1 Buoys Under Relatively Free Drift........................ .............. ............... 167
8.5.2.2 Coastal Shallow Water Buoy Drift.......................... ........................... 169
8.5.3 Large-Scale Sea-Ice Tracking Using Visible Wavelength Data .................. 170
8.5.4 Small-Scale Sea-Ice Tracking from SAR............................................... 171
8.5.4.1 Perennial Ice Drift.......................................................................... 172
8.5.4.2 Seasonal Ice Drift................................ ............. ....... ......... .............. 173
8.5.4.3 Sea-Ice Deformation....................................................................... 175
Analysis of SAR Data of the Polar Oceans
Edited by C. Tsatsoulis and R. Kwok
© Springer-Verlag Berlin Heidelberg 1998
Satellite Microwave Radar Observations of Antarctic Sea Ice
M.R. DRINKWATER
Contents
8.1 Introduction...................................................................................... 146
8.2 Obtaining Spaceborne Radar Data in Antarctica..................................... 147
8.2.1 Antarctic SAR Data................. ................................... ....................... 147
8.2.1.1 ERS-l and ERS-2 SAR...................................................................... 147
8.2.1.2 J-ERS-l SAR .................................................................................. 147
8.2.1.3 RADARSAT SAR ............................................................................ 148
8.2.1.4 ERS SAR Backscatter Calibration Accuracy........................................ 148
8.2.2 Antarctic SAR Receiving Stations....................................................... 149
8.2.3 Scatterometer Imaging........................ ......... .... ....... .... ....... ....... ........ 150
8.3 Sampling Issues.................................................................................. 150
8.3.1 Temporal and Spatial Coverage.... .................... ...................... ............. 150
8.3.2 Filling the Gaps................................................................................
151
8.4 Ice Classification Issues ......................... ............... .............. ........... ......
151
8.4.1 Backscatter Characteristics of Antarctic Ice.......................... ................ 152
841.1 Shipborne Scatterometer Signatures .......... ....................................... 152
8.4.1.2 Regional Winter C-band Backscatter Variability.......... ....................... 157
8.4.1.3 Snapshot Signature Summary.......................................................... 161
8.4.2 The Future of Ice Classification.......................................................... 163
8.4.2.1 Scatterometer Ice Classification....................................................... 163
842.2 Multichannel and Multisensor Data Fusion....................................... 165
8.5 Antarctic Sea Ice Dynamics.................................................................. 165
8.5.1 Length Scales of Antarctic Sea-Ice Drift ............................................... 165
8.5.1.1 Coastal Regime .... ......................... .................... .................... ......... 166
8.5.1.2 Central Basin................................................................................. 166
8.5.2 Motion Spectra and Temporal Covariance with Wind.. ................ .......... 167
8.5.2.1 Buoys Under Relatively Free Drift........................ .............. ............... 167
8.5.2.2 Coastal Shallow Water Buoy Drift.......................... ........................... 169
8.5.3 Large-Scale Sea-Ice Tracking Using Visible Wavelength Data .................. 170
8.5.4 Small-Scale Sea-Ice Tracking from SAR............................................... 171
8.5.4.1 Perennial Ice Drift.......................................................................... 172
8.5.4.2 Seasonal Ice Drift................................ ............. ....... ......... .............. 173
8.5.4.3 Sea-Ice Deformation....................................................................... 175
Analysis of SAR Data of the Polar Oceans
Edited by C. Tsatsoulis and R. Kwok
© Springer-Verlag Berlin Heidelberg 1998