Instrument Information
IDENTIFIER urn:nasa:pds:context:instrument:rss.co::2.1
NAME RADIO SCIENCE SUBSYSTEM
TYPE
DESCRIPTION The Cassini Radio Science instrument included elements on both the spacecraft and the ground. The spacecraft element (covered by this context product) was further distributed among several subsystems on the Orbiter, while the ground element included NASA Deep Space Network (DSN) complexes in California, Australia, and Spain and occasional support from other ground stations such as antennas of the European Space Agency tracking network. The Radio Science 'instrument' operated in two fundamental modes. For 'two-way' measurements, the 'uplink' signal from the ground could be a single carrier at either X-band (7.2 GHz) or Ka-band (34 GHz); or both carriers could be transmitted at the same time. The spacecraft radio equipment then acted as a repeater, collecting the carrier signal with the spacecraft High Gain Antenna (HGA) and transforming it to one or more 'downlink' frequencies (2.3 GHz, 8.4 GHz, or 32 GHz) by elements in the Radio Frequency Subsystem (RFS) and Radio Frequency Instrument Subsystem (RFIS). For 'one-way' measurements, the signal source was on board the Cassini Orbiter; the output from an Ultrastable Oscillator (USO) was transformed to downlinks at 2.3, 8.4, or 32 GHz. The downlink signals were amplified and radiated through the HGA toward Earth. After passing through the medium of interest (e.g., plasma, rings, a neutral atmosphere or gravitationally curved space), the perturbed signal was collected by a ground antenna, amplified, down-converted, and recorded for later analysis.
MODEL IDENTIFIER
NAIF INSTRUMENT IDENTIFIER
SERIAL NUMBER not applicable
REFERENCES Asmar, S. W., N. A. Renzetti, The Deep Space Network as an Instrument for Radio Science Research, JPL Publication 80-93, Rev. 1, April 15, 1993.

Deep Space Mission Systems, Tracking and Navigation Service, Requirements and Design, DSMS No. 821-104, Rev. B, JPL D-17235, Jet Propulsion Laboratory, Pasadena, CA, 2003.

Deep Space Mission Systems, Radio Science Service, Requirements and Design, DSMS No. 821-110, Rev. A, JPL D-17241, Jet Propulsion Laboratory, Pasadena, CA, 2001.

Deep Space Mission System/Cassini Project Network Operations Plan, JPL Document DSN 871-011, March 2003.

Kliore, A.J., J.D. Anderson, J.W. Armstrong, S.W. Asmar, C.L. Hamilton, N.J. Rappaport, H.D. Wahlquist, R. Ambrosini, F.M. Flasar, R.G. French, L. Iess, E.A. Marouf, and A.F. Nagy, Cassini Radio Science, Space Science Reviews, 115, 1, 1-70, November 2004.