BackForwardInstrument:  SSTI 

Instrument details
Acronym SSTI
Full name Satellite-to-Satellite Tracking System
Purpose Solid Earth - Observation of the Earth’s gravity field along the orbit
Short description A Lagrange receiver capable of simultaneous tracking of up to 12 GPS satellites, for very accurate positioning
Background New development
Scanning Technique N/A
Resolution N/A
Coverage / Cycle N/A
Mass 6.1 kg Power 35 W Data Rate


Providing Agency ESA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2009 to 2013
Last update: 2022-07-25
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
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