BackForwardInstrument:  AltiKa 

Instrument details
Acronym AltiKa
Full name Ka-band Altimeter
Purpose Ocean topography, significant wave height, wind speed on sea surface; specific to sea-surface height
Short description Single frequency in the Ka-band (35.75 GHz) with built-in dual-frequency radiometer (23.8 and 36.5 GHz)
Background New development
Scanning Technique Nadir-only viewing, continuous sampling along track
Resolution 10 km
Coverage / Cycle Global coverage in 35 days (repeat cycle), 30 km average spacing
Mass 40 kg Power 85 W Data Rate 43 kbps


Providing Agency CNES
Instrument Maturity Demonstrated by simulations
Utilization Period: 2013 to 2024
Last update: 2021-06-15
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
  • Subcomponent 1
  • Wide-swath radar altimeters, and high altitude, inclined, high-precision orbit altimeters
  • Conventional radar altimeter
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)3 - highAlong-track only.Single-frequency Ka-band radar altimeter
Geoid*2 - very highLong time series needed.. Along-track only.Geoid derived from multi-temporal analysis of radar altimetry data
Gravity field4 - fairPartial information (geoid).. Along-track only.Gravity field derived from multi-temporal analysis of radar altimetry data
Ocean dynamic topography*3 - highLong time for mapping.. Along-track only.Single-frequency Ka-band radar altimeter
Significant wave height*2 - very highAlong-track only.Ka-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
Ice sheet topography3 - highInfrequent coverage.. Along-track only.Ka-band radar altimeter