Marine Gravity from the first two cycles of the Jason-2 LRO extension of Life mission

Ole Baltazar Andersen (Dr, Denmark)

CoAuthors

Adili Abulatitijiang (DTU Space, Denmark)

Event: 2019 Ocean Surface Topography Science Team Meeting

Session: The Geoid, Mean Sea Surfaces and Mean Dynamic Topography

Presentation type: Type Oral

In July 2017 Jason-2 was put in a End-of-Life orbit the so-called GM/LRO orbits. The design of the orbit was such that after approximately 2 cycles or a little more than 2 years complete coverage with a equal track spacing of 4 km across track would be achieved to the huge benefit of marine geodesy. The optimal Jason-2 LRO orbit was chosen to be 27 km lower than the nominal orbit and designed to have a fallback geodetic sub-cycle of approximately 145 days. This sub-cycle was selected as a "coarse geodetic grid", i.e. as a safety net if full geodetic cycles cannot be completed. The strategy was inherited from Jason-1 EoL trying to optimize all sub-cycles to make it valuable to oceanography as well (shorter ones for sea-state and mesoscale, and longer ones for geodesy).
The first GM/LRO cycle was completed in summer of 2018. During the first cycle safe-hold modes created a number of small set of 8-km gaps that are sometimes next to the ongoing and incomplete 145-day sub-cycle. Approximately 13% of the data have been lost to safe hold modes.
During the second GM/LRO cycle (presently incomplete), a longer safehold of several month was encountered during the spring of 2019 and after the restart of the instrument in May 2019, it has been decided to revind the Gm to fill in this long safehold-gap before continue into the third cycle.
In this presentation the first two cycles of Jason-2 GM/LRO data and the importance of these for marine gravity field modelling. The Jason-2 waveforms should be superior to the Jason-1 waveforms and we analyse the effect on this for gravity field modelling.

 

Oral presentation show times:

Room Start Date End Date
The Monroe Hub Thu, Oct 24 2019,09:00 Thu, Oct 24 2019,09:15
Ole Baltazar Andersen
Dr
Denmark
oa@space.dtu.dk