BackForwardInstrument:  EGG 

Instrument details
Acronym EGG
Full name 3-Axis Electrostatic Gravity Gradiometer
Purpose Observation of the Earth’s gravity field along the orbit
Short description Three pair of 3-axis accelerometers specially assembled to measure the gravity-gradient tensor
Background New development
Scanning Technique N/A
Resolution N/A
Coverage / Cycle N/A
Mass 150 kg Power 75 W Data Rate


Providing Agency ESA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2009 to 2013
Last update: 2023-02-08
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.Accelerometer to reconstruct the Earth's gravity field, hence the geoid
Gravity field*2 - very highAssimilation in gravity model needed.Accelerometer to reconstruct the Earth's gravity field
Gravity gradients*3 - highAssimilation in gravity model needed.Accelerometer/gradiometer to reconstruct the Earth's gravity field
Atmospheric density5 - marginalNo specific limitation.Accelerometer/gradiometer. Atmospheric density measured as one of the perturbations of accelerometer records due to atmospheric drag