Soundings of Titan's atmosphere by Cassini using the two-way radio occultation technique
Abstract
In December 2011 the Ultra Stable Oscillator aboard Cassini failed, and all subsequent radio occultations have been done using the two-way technique. The two-way technique uses a highly stable frequency reference on the ground rather than the on board USO. A pure X band tone is transmitted to the spacecraft, and that uplink signal as Cassini receives it is used as the frequency reference for the three returned S, X, and Ka band tones transmitted by the spacecraft. On May 17 and June 18 of 2014 two occultations of Cassini by Titan occured, during targeted Titan encounters T101 and T102, and were done using the two-way technique for the first time for Titan occultations. We present the four soundings of Titan's atmosphere obtained from the resulting data using the two way numerical inversion technique described in Schinder et al., Radio Science 50, 712. The ingress occultation on T101 occured at 66 N latitude and egress is at 46 S. On T102, ingress occured at 63 N and 66 S latitude. We will also place these results in context with the earlier Titan occultations (Schinder et al., Icarus 215, 460; Schinder et al., Icarus 221, 1020) done in one way mode.
- Publication:
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AAS/Division for Planetary Sciences Meeting Abstracts #47
- Pub Date:
- November 2015
- Bibcode:
- 2015DPS....4731007S