Towards NGGM: Laser Tracking Instrument for the Next Generation of Gravity Missions

authored by
Kolja Nicklaus, Kai Voss, Anne Feiri, Marina Kaufer, Christian Dahl, Mark Herding, Bailey Allen Curzadd, Andreas Baatzsch, Johanna Flock, Markus Weller, Vitali Müller, Gerhard Heinzel, Malte Misfeldt, Juan Jose Esteban Delgado

The precise tracking of distance variations between two satellites in low Earth orbit can provide key data for the understanding of the Earth’s system, specifically on seasonal and sub-seasonal water cycles and their impact on water levels. Measured distance variations, caused by local variations in gravitational field, serve as inputs to complex gravity models with which the movement of water on the globe can be identified. Satellite missions GOCE (2009–2013) and GRACE (2002–2017) delivered a significant improvement to our understanding of spatial and temporal gravity variations. Since 2018, GRACE Follow-On has been providing data continuity and features for the first time through the use of a laser interferometer as the technology demonstrator, in addition to a microwave ranging system as the main instrument. The laser interferometer provides an orders-of-magnitude lower measurement noise, and thereby could enable a significant improvement in the measurement of geoids if combined with suitable improvements in auxiliary instrumentation and Earth system modelling. In order to exploit the improved ranging performance, the ESA is investigating the design of a ‘Next Generation Gravity Mission’, consisting of two pairs of satellites with laser interferometers, improved accelerometers and improved platform performance. In this paper, we present the current design of the laser interferometer developed by us, the development status of the individual instrument units and the options available.

PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
Institute of Gravitation Physics
CRC 1464: Relativistic and Quantum-Based Geodesy (TerraQ)
External Organisation(s)
Max Planck Institute for Gravitational Physics (Albert Einstein Institute)
SpaceTech GmbH Immenstaad (STI)
Remote sensing
Publication date
Publication status
Peer reviewed
ASJC Scopus subject areas
Earth and Planetary Sciences(all)
Electronic version(s) (Access: Open)