BackForwardInstrument:  HAIRS 

Instrument details
Acronym HAIRS
Full name High Accuracy Inter-satellite Ranging System
Purpose Solid Earth - Observation of the gravity field along the orbit
Short description Two-frequency ranging, in K-band (24 GHz) and Ka-band (32 GHz)
Background New development
Scanning Technique N/A
Resolution N/A
Coverage / Cycle N/A
Mass Power Data Rate


Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2002 to 2026
Last update: 2023-02-10
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
  • Other payload component
  • Gravity sensing system
WIGOS Subcomponents
  • Subcomponent 1
  • Gravimetry missions
  • Gravitometry sensing system
Mission objectives
Primary mission objectives
  • Gravity field
  • Gravity gradients
  • Ground water
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
Geoid3 - highHighly indirect.Multi-satellite system to reconstruct the Earth's gravity field, hence the geoid
Gravity field*1 - primaryAssimilation in gravity model needed.Multi-satellite system to reconstruct the Earth's gravity field
Gravity gradients*1 - primaryAssimilation in gravity model needed.Satellite-to-satellite tracking system to reconstruct the Earth's gravity field