Geostatistical evaluation of satellite radar altimetry for high-resolution mapping of Lambert Glacier, Antarctica

摘要: The potential of satellite radar altimetry for high-resolution mapping Antarctic ice streams is evaluated, using retracked and slope-corrected data from the Lambert Glacier Amery Ice Shelf area, East Antarctica, acquired by Geosat during Exact Repeat Mission (ERM), 1986-89. map area includes lower north 72.18 deg S, southern Shelf, grounded inland sheet on both sides. ERM found to provide substantially more complete coverage than 1978 Seasat altimetry, due improved tracking. Variogram methods are used estimate noise levels in as a function position throughout area. spatial structure quantified constructing experimental variograms grounding zone Glacier, which chiefly interest this topographically complex region. Kriging employed invert along-track height measurements onto fine-scale 3 km grid. unsmoothed yields spatially continuous maps showing main topographic features upper adjacent sheet. probable line identified break slope at ice/floating transition. approximate standard error kriged inferred levels.