Airborne gradiometry in coastal areas – GREMLIT

Knowing the gravity field and the geoid in coastal areas is a challenge of primary importance, in order to comprehend the coastal environment and its dynamics, for instance for studying the coastal currents from altimetric measurements, for the determination of the geodetic and hydrographic references, for the exploitation of natural ressources and for passive navigation. For that aim, it is necessary to homogeneize and densify the gravimetric coverage in the whole land-sea transition area, given the heterogeneity of the present coverage and the lask of land-sea continuity.

In this context, the objective of this project is to study the interest of airborne planar gradiometry, as a complement to the existing surface gravity data (on land and at sea) and to the GOCE satellite gradiometry data, for the determination of the gravity field and the understanding of the coastal environment. This projects aims at determining the conditions to be fulfilled by 1) a planar electrostatic gradiometer based on the electrostatic accelerometers from the CHAMP, GRACE and GOCE missions, taking into account the precision on the positioning and attitude control of the plane, and 2) the gradiometer decoupling platform that allows to separate the gradiometric measurement from the carrier noise and is a key element of the system. This project will thus allow us to conclude on the feasability of such system and its scientific interest.

This project is aimed to support an ONERA PhD thesis for which an application for complementary funding is being submitted to DGA.