Detecting ice-sheet topography with AVHRR, RESURS-01, and landsat TM imagery

The ability of different visible-band satellite imagers to detect subtle ic e-sheet topographic features is examined by both qualitative and quantitati ve comparisons. The AVHRR 10-bit sensor is shown to have the best radiometr ic resolution, but its poorer spatial resolution limits this sensor's abili ty to discriminate smaller scale topography. RESURS-01 is a less-well known 8-bit sensor, but this instrument's higher noise and poorer radiometric re solution restrict its utility for ice-sheet research. Landsat TM applies 8- bit quantization over a narrower radiometric range, causing it to saturate for some conditions. This limitation allows TM to achieve a radiometric res olution half that of AVHRR while retaining a much higher spatial resolution . No SPOT imagery was compared, but the sensor is shown to have less radiom etric resolution than TM. However SPOT has better spatial resolution and is less likely to saturate.