BackForwardInstrument:  GLAS 

Instrument details
Acronym GLAS
Full name Geoscience Laser Altimeter System
Purpose Polar ice sheet thickness and topography.  Also cloud top height and aerosol
Short description Two-wavelength lidar (532 and 1064 nm). A Stellar Reference System (SRS) that includes a star tracker and a Laser Reference System (LRS) provide accurate positioning and co-referencing of the pulses at the two wavelengths.
Background New development
Scanning Technique Nadir-only viewing, sampling at 170 m intervals along track, near continuous profiling
Resolution Horizontal: 66 m IFOV sampled at 170 m intervals along track.  Vertical: 10 cm surface, 200 m cloud top
Coverage / Cycle Global coverage in 91 d (orbit repeat cycle, with 8d and 33d sub-cycles) leaving cross-track 2.5 km gaps at 80° latitude, 15 km at equator
Mass 298 kg Power 300 W Data Rate 450 bps

 

Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2003 to 2010
Last update: 2017-03-31
Detailed characteristics
Satellites this instrument is flying on

Note: a red tag indicates satellites no longer operational, a green tag indicates operational satellites, a blue tag indicates future satellites

Instrument classification
  • Earth observation instrument
  • Active and radio-occultation sensor
  • Lidar (Doppler lidar, backscatter lidar, lidar Dial, lidar altimeter)
WIGOS Subcomponents
  • Subcomponent 2
  • Lidar (single wavelength) (in addition to radar missions mentioned in Component 1)
  • Lidar (Altimeter - for surface)
Mission objectives
Primary mission objectives
  • Coastal sea level (tide)
  • Geoid
  • Gravity field
  • Ice sheet topography
  • Ocean dynamic topography
  • Sea-ice elevation
  • Sea-ice thickness
Evaluation of Measurements