Specific Action Gravimetry Resif

Since March 2022, the gravimetry activities have been reorganized within the Specific Action Gravimetry Resif, regrouping the two previous actions (permanent gravimetric network and mobile gravimetric park), with the aim of managing all the activities of the domain within a single office.

The Action relies on the PGrav National Instrument Park, which offers scientific teams a set of means of measurements and services for studies of the gravity field and is based on the following three issues: temporal monitoring; metrology; referencial & imaging.

PGrav Instrumental Park

PGrav is composed of absolute and relative gravimeters of different classes and different technologies allowing to cover a wide range of applications. These different sensors allow to measure, with a precision ranging from a few 10^-8 g to a few 10^-11 g, the spatial or temporal variations of gravity. They are used in laboratories for characterization, calibration, instrumental monitoring or comparison purposes and also for permanent or semi-permanent measurements. Most of them are then implemented in the field for reconnaissance surveys and network establishment. These instruments contribute to characterize and quantify mass or density variations occurring in the vicinity of the Earth’s surface or within the Earth.

Complemented by other gravimetric measurement means available in France from various organizations or from other projects (EQUIPEX, CPER, etc.), the Specific Action Gravimetry Résif contributes today to consolidate a first class national gravimetric infrastructure built over several decades and allowing to answer to many applications of fundamental or applied research in geodesy, geophysics, geology, hydrology, oceanography or metrology.

Gravimeters of the PGrav park:

• 5 absolutes: 2 “corner cube” and 3 “cold atoms” sensors
• 6 relatives spring field sensors
• 4 relatives superconducting observatory sensors

The instruments of the PGrav park are at the disposal of the national scientific community, within the limit of their availability. Their use is governed by the national instrument charter and the PGrav charter. Requests to borrow instruments can only be made via the online form.

Download

Charter for the use of the instruments of the national gravimetric park PGrav

Access to the loan request form

The management of the instrumental park is ensured by the CNRS-INSU Direction Technique tool. Borrowers have access via a user account (the login is: “user” and the password is also: “user”), which allows them to consult the instrument use schedule, updated according to the accepted loans.

Access to the park management tool

Objectives

The main objectives of the Action are to :

• federate the French community around the national means of measurement in gravimetry, absolute and relative, continuous and repeated;
• maintain and make available to the scientific community a reliable, metrological, traceable and modern instrumentation, answering the needs of the users and to exchange expertise in acquisition, processing and exploitation of gravity measurements;
• upport the research and development activities in the field of the measurement of the terrestrial gravity field (including the realization of campaigns or observation networks and the development or the validation of new generation sensors);
• insert and valorize the work carried out by the community of users, both within the framework of the national infrastructures, but also within the framework of the strategies of gravimetric observation promoted by the international organizations (in particular: International Association of Geodesy (IAG) and Consultative Committee for Mass and Associated Quantities of the International Committee for Weights and Measures (CIPM-CCM));
• maintain the reference network of absolute repeated measurements RésRéf and to contribute to the continuous monitoring of the temporal variations of gravity carried out from a set of permanent Observatories hosting superconducting gravimeters. These last activities, added to the contribution to the scientific services of the IAG including the International Gravimetric Bureau (BGI) and the International Geodynamics and Earth Tides Service (IGETS), constitute the SNO Gravimetry.