SC 2.3: Satellite Gravity Missions

Chair: Frank Flechtner (Germany)
Vice-Chair: Matthias Weigelt (Germany)

Terms of Reference

The successful launches of the German CHAMP (2000), the US/German GRACE (2002), the ESA GOCE (2009) and US/German GRACE-FO (2018) missions have led to a revolution in global gravity field mapping by space-borne observation techniques. These missions are the only measurement systems which can directly observe mass distribution and mass transport in the Earth system based on proven new concepts and technologies, such as high-low satellite-to-satellite tracking (SST) using the GPS constellation, low-low SST based on micro-wave and laser ranging, and satellite gravity gradiometry (SGG), as well as space-borne accelerometry. GRACE has produced 15+ years consistent long- to medium-wavelength global gravity field models and its temporal changes till June 2017 which are extended since May 2018 by GRACE-FO data. GOCE provided high- accuracy and high-resolution static gravity field models. In combination with complementary gravity field information from terrestrial data and satellite altimetry, an even higher spatial resolution can be achieved. Consequently, these satellite missions provide valuable contributions to many geoscientific application fields, such as geodesy, hydrology, oceanography, glaciology, and solid Earth physics.

Objectives

The focus of SC 2.3 will be to promote and stimulate the following activities:

• providing the scientific environment for the development of the next generation of static and temporal gravity field solutions based on observations from the satellite gravity missions CHAMP, GRACE, GOCE, and GRACE-FO, as well as optimum combination with complementary data types (SLR, terrestrial and air-borne data, satellite altimetry, etc.),
• developing alternative methods and new approaches for global gravity field processing with special emphasis on functional and stochastic models and optimum data combination,
• fostering the exchange of knowledge and data among processing entities,
• communication and interfacing with gravity field model user communities (climatology, oceanography/altimetry, glaciology, solid Earth physics, geodesy, ...) as well as relevant IAG organizations such as the GGOS Committee on Satellite and Space Missions and the GGOS Bureau of Products and Standards,
• identification, investigation and definition of enabling technologies for future gravity field missions such as observation types, technologies or mission architectures, and
• triggering new gravity field mission proposals and supporting their implementation

Program of Activities 

The sub-commission will establish, if necessary, Working Groups on relevant topics. The Steering Committee will work closely with members and other IAG commissions and sub-commissions to obtain mutual goals. Also it will promote and jointly sponsor special sessions at IAG Symposia and other workshop/conferences.