BackForwardInstrument:  NRA 

Instrument details
Acronym NRA
Full name NASA Radar Altimeter
Purpose Ocean topography, significant wave height, wind speed
Short description Two frequencies (5.3 and 13.6 GHz)
Background New development
Scanning Technique Nadir-only viewing, sampling at 30 km intervals along track
Resolution 30 km
Coverage / Cycle Global coverage in 1 month for 30 km average spacing, or in 10 days for 100 km average spacing
Mass 230 kg Power 237 W Data Rate 9.8 kbps

 

Providing Agency NASA
Instrument Maturity
Utilization Period: 1992 to 2005
Last update: 2013-02-15
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
  • Radar altimeter
WIGOS Subcomponents No WIGOS subcomponents have been defined.
Mission objectives
Primary mission objectives
  • Geoid
  • Ocean dynamic topography
  • Significant wave height
Evaluation of Measurements

The following list indicates which measurements can typically be retrieved from this category of instrument. To see a full Gap Analysis by Variable, click on the respective variable.

Note: table can be sorted by clicking on the column headers
Note: * Primary mission objective.
VariableRelevance for measuring this variableOperational limitationsExplanation
Coastal sea level (tide)2 - very highAlong-track only.Dual-frequency radar altimeter: Ku-band and supporting S-band or C-band to correct for ionospheric rotation
Geoid*1 - primaryLong time series needed.. Along-track only.Geoid derived from multi-temporal analysis of radar altimetry data. Typical orbit for geodetic use: 1336 km height, 66° inclination
Gravity field4 - fairPartial information (geoid).. Along-track only.Gravity field derived from multi-temporal analysis of radar altimetry data. Typical orbit for geodetic use: 1336 km height, 66° inclination
Ocean dynamic topography*2 - very highLong time for mapping.. Along-track only.Dual-freqency altimeter: Ku-band and supporting S-band or C-band to correct for ionospheric rotation
Significant wave height*2 - very highAlong-track only.Ku-band radar altimeter
Wind speed (near surface)5 - marginalOver sea only.. Along-track only.Radar altimeter. Wind speed estimated from the intensity of the backscattered signals
Ionospheric Vertical Total Electron Content (VTEC)4 - fairAlong-track only.Dual-frequency altimeter: Ku-band and supporting S-band or C-band to correct for ionospheric rotation