Performance of the TGRS Radio Occultation Instrument

In June of 2019, a complement of TGRS (TriG GNSS Receiver System) radio occultation (RO) instruments were launched into low Earth orbit aboard six COSMIC-2 satellites. Each TGRS is tasked with providing low latency observations of the ionosphere and atmosphere using multiple antennas to observe GPS and GLONASS satellites as they rise above the Earth’s limb and set on the opposite side. This combination of 2 GNSS constellations and views of the forward and aft directions along the spacecraft velocity vector allows for approximately 1000 vertical profiles of the ionosphere and atmosphere each day from each TGRS.

TGRS has many improvements over the RO instrument deployed for COSMIC-1. A few of these are an oscillator with excellent short term stability, fully open-loop phase processing of RO data and a high-gain, digitally steered antenna array. In this talk, we will show some results from the six TGRS instruments on COSMIC-2 and describe how well the TGRS performance matches its requirements for the mission based on data taken in the first months of operation.