GLIMS: Global Land Ice Measurements from Space

Monitoring the World's Changing Glaciers

Summary of Glacier Remote-Sensing Instrument Characteristics

ASTER
Adanced Spaceborne Thermal Emission and reflection Radiometer

Date of launch:	July 1999
Total number of nadir-looking bands:	14
Swath width:	60 km
Stereo capability:	Yes, in 760-860 nm VNIR band 3 (along-track; 53 second time separation between pairs)
Cross-track pointing capability:	Yes

Bands	Wavlength coverage (nm)	Spatial resolution (m)	Cross-track pointing (km)	Quantization (bits)
VNIR 1-3	520-860	15	+/- 24 deg (318 km)	8
SWIR 4-9	1600-2430	30	+/-8.55 deg (116 km)	8
TIR 10-14	8475-11650	90	+/-8.55 deg (116 km)	12

Landsat 4, 5 (Thematic Mapper)

Period of TM operations, Landsat 4:	July 1982-August 1993
Period of TM operations, Landsat 5:	March 1983-present
Total number of nadir-looking bands:	7
Swath width:	185 km
Stereo capability:	No
Cross-track pointing capability:	No

Bands	Wavlength coverage (nm)	Spatial resolution (m)	Quantization (bits)
VNIR 1-4	450-900	30	8
SWIR 5,7	1550-2350	30	8
TIR 6	10400-12500	120	8(?)

Landsat 7 (Enhanced Thematic Mapper Plus)

Date of launch:	April 1999
Total number of nadir-looking bands:	8
Swath width:	183 km
Stereo capability:	No
Cross-track pointing capability:	No

Bands	Wavlength coverage (nm)	Spatial resolution (m)	Quantization (bits)
VNIR 1-4	450-900	30	best 8 of 9 bits
SWIR 5,7	1550-2350	30	best 8 of 9 bits
TIR 6	10400-12500	120	best 8 of 9 bits
Panchromatic	520-900	15	best 8 of 9 bits

RADARSAT

Date of launch:	November 1995

SAR (Synthetic Aperture Radar) characteristics
Frequency / Wavelength	5.3GHz/C-band 5.6 cm
RF Bandwidth	11.6, 17.3 or 30.0 Mhz
Transmitter Power (peak)	5 kW
Transmitter Power (average)	300 W
Maximum Data Rate	85 Mb/s (recorded) - 105 Mb/s (R/T)
Antenna Size	15m x 1.5m
Antenna Polarization	HH

Imaging Mode	Resolution¹ Range x azimuth (km)	# Looks²	Scene Width (km)	Incidence Angle³, (°)
Standard	25 x 28	4	100	20-49
Wide 1	48-30 x 28	4	165	20-31
Wide 2	32-25 x 28	4	150	31-39
Fine res	11-9 x 9	1	45	37-48
ScanSAR narrow	50 x 50	2-4	305	20-40
ScanSAR wide	100 x 100	4-8	510	20-49
extended (H)	22-19 x 28	4	75	50-60
extended (L)	63-28 x 28	4	170	10-23

¹ Nominal; ground range resolution varies with range
² Nominal; range- and processor-dependent
³ Incidence angle depends on sub-mode

GLAS
Geoscience Laser Altimeter System

Date of launch:	July 2001

This EOS instrument, to ride on the ICESat platform, is a Laser Altimeter (non-imaging), which has a nadir-pointing Nd:YAG laser pulsed at 40 Hz. Each laser beam makes a 70 m spot on the ground; these spots are separated by 170 m. Cross-track resolution ranges from 15 km at the equator to 2.5 km at 80 degrees latitude. The instrument will run continuously.

By measuring the round-trip time for the laser pulses, and by accurately knowing the position of the ICESat platfrom via the on-board GPS receivers, topography will be accurately determined. The main application is ice-sheet topography.