The Unique Role of Jason-2 Geodetic Mission for high Resolution Gravity Field Modelling

Abstract:

Resolution of current global altimetric gravity models is around 12 km resolving 6km wavelength features and for many years it has been difficult to improve the resolution further in a systematic way. The Geodetic Mission of Jason-2, which was carried out as a part of its Extension-of-Life mission, was the first geodetic mission planned to provide ground-tracks with a systematic spacing of 4 km after 2 years and 2 km after 4 years and in this way increase the spatial resolution of global altimetric gravity fields. Despite the fact, that the satellite ceased operation in October, 2019 after 2 years of Geodetic Mission it still provided a fantastic dataset for gravity recovery. We highlight the improvement to the gravity field which could be derived from the 2 years GM.

When the Extension-of-Life phase is conducted, the satellite is old and particularly Jason-2 suffered from several safe-holds and instrument outages during the GM. Here, we try to quantify the effect of safe-holds on marine gravity and discuss suitable approaches advising future GM like Jason-3. We evaluate the importance of attempting to “rewind” the mission to recover missing tracks as well as the possibility to continue an existing GM by interleaving satellites in the same orbital plane. The latter idea would allow to continue the already 2-years Jason-2 GM rather than starting all over with a new GM.