Projet MoVeGra

Project  “Mobile Underwater Vector Gravity Sensor” (MoVeGra)

The objective of MoVeGra is to mature the technology of a novel type of vector gravity sensor to be used on Autonomous Underwater Vehicles (AUV). This proposal is the follow-up of a larger project, GRAVIMOB, which developed and built the first prototype and tested it during a cruise (GRAVIMOB 2016, funded by the French Oceanographic Fleet-FOF).

the objectives of ANR research axis 01 as this new sensor will allow:

  • improving the knowledge of the crustal structure (porosity, alteration) and fluid circulation associated with hydrothermal vents, which impact the fluxes of diverse elements, and,
  • evaluating the economic potential of the mineral deposits associated with these environments.

The concept of GRAVIMOB is based on direct measurements of accelerations along three axes (De Saint Jean, 2008). The system is composed of six accelerometers mounted in two co-linear triads, integrated on a glass sphere, which also holds the data loggers and additional sensors (Figure 1). It is therefore a vector gravity meter allowing, after data processing, to determine the three components of the gravity acceleration.

GRAVIMOB sensor (left), sphere in a frame for AUV AsterX (centre), AUV AsterX (right) AUV AsterX @IFREMER

Main partners: LGO  ESGT (Le Mans)

Collaborations: IGN, SHOM, IFREMER
Prototype built by  MAPPEM Geophysics, funded by CPER Bretagne

Test cuise GRAVIMOB (NO Europe, AUV AsterX), May 2016, funded by FOF, Labex MER, LGO

Cruise evaluation (CNFH)

Cruise operational report

Cruise scientific report

Test cruise GRAVIMOB-2 (NO Europa, AUV) evaluated A+ by the French Coastal Fleet Committee (CNFC)

Cruise evaluation (CNFC)

Bibliography

Roussel, C., J. Verdun, J. Cali, M. Maia, and J. F. d’EU. “Integration of a strapdown gravimeter in an autonomous vehicle.” ISPRS – International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL– 5/W5 (April 9, 2015) : 199–206. doi :10.5194/isprsarchives-XL-5-W5-199-2015

Thèse (DGA): Roussel, C. Expérimentation d’un gravimètre mobile léger et novateur pour la mesure du champ de gravité en fond de mer, 2017 (https://tel.archives-ouvertes.fr/tel-01635884)

Element XR mass spectrometer

High Resolution Inductively Coupled Plasma Source Mass Spectrometer (HR-ICPMS) and 193 nm Compex Pro 102 Coherent Laser Ablation System

spectrométrie

X-Series 2 Mass Spectrometer

Quadrupole Mass Spectrometer Coupled with Induced Plasma (ICP-Q-MS)

TRITON mass spectrometer

Thermo-ionization Mass Spectrometer (MC TI-MS)

ULTIMA2

ULTIMA2 Optical Spectrometer