NSSDCA ID: PSRI-00014
Availability: Archived at NSSDC, accessible from elsewhere
This description was generated automatically using input from the Planetary Data System.
Products include all X-, S-, and Ka-band RSS ring occultations completed before the loss of the Cassini UltraStable Oscillator (USO) in late 2011. The 'TAU' files contain calibrated optical depth and phase shift profiles of Saturn's rings reconstructed from the diffraction-limited measurements. The frequency/phase measurements reference is the Cassini UltraStable Oscillator (USO). The reconstruction is carried out using algorithms described at length in MAROUFETAL1986. Practical implementation steps are provided in an included documentation file, archived_rss_ring_profiles_2018.pdf. Each occultation consists of several companion products . These include one or more reconstructed profiles (TAU) files for the same occultation but at different resolutions, and two which provide geometry and calibration data. The latter two have file names constructed from the same root as this file with the field for radial resolution removed and the 'TAU' replaced by either 'GEO' (geometry) or 'CAL' (carrier frequency and power calibration). For some resolutions, diffraction-limited profiles (DLP) files are also included. In such cases, the DLP file name lists the DLP resolution and 'TAU' is replaced by 'DLP.' Both 1 km (or best achievable resolution per experimental conditions) and 10 km resolution reconstructed profiles (TAU) files are included. We define spatial resolution as the shortest resolvable wavelength in a reconstructed profile. The definition is convenient for characterization of multiple resolution profiles generated from a reference reconstructed profile of resolution much finer than 1 km (when experimental conditions allows). The shortest resolvable wavelength is the inverse of the highest spatial frequency preserved in the data and is determined by the bandwidth of the lowpass filter applied at the end of the data processing chain. The archived 1 km resolution profile is identical to one reconstructed directly from the archived 0.5 km resolution diffraction-limited data processed to achieve 0.75 km 'processing resolution', where the latter is defined by Eq. 19 of MAROUFETAL1986.
As discussed in MAROUFETAL1986, actual reconstructed profile resolution can be impacted by several factors including stability of the reference oscillator. The latter is usually characterized by the Allan deviation/variance. Typical values of the Cassini USO Allan deviation is 2E-13 over 1s and 1E-13 over 10-100s. The USO Allan deviation changed little over the USO lifetime. Cassini USO stability does not measurably impact reconstruction resolution down to the meters range. Details of the processing are given in Marouf et al., 1986.
Version 1 - RSS occultations 2005 - 2008. - X Band only - post diffraction correction, radial profiles at 1 and 10 km sampling. Version 2 - includes reprocessed versions of the material contained in the earlier version, plus all subsequent RSS occultations obtained prior to the loss of the Cassini UltraStable Oscillator (USO) in late 2011. - includes 'DLP' files for each observation which contain higher resolution calibrated but diffraction-limited optical depth and phase shift profiles of Saturn's rings, that is, calibrated profiles before reconstruction to remove diffraction effects. - Version 2 contains K, S, and X band data.
For questions concerning this data set contact: Mitch Gordon PDS Rings Node SETI Institute 189 Bernardo Mountain View, CA 94043 Phone: 276-393-8822 Email: mgordon@seti.org Prof. Essam Marouf, Electrical Engineering Department, San Jose State University, San Jose, CA 95192-0084; Phone: (408) 924-3969; Email: essam.marouf@sjsu.edu.
These data are available on-line from the Planetary Data System (PDS) at:
https://pds-rings.seti.org/holdings/volumes/CORSS_8xxx/CORSS_8001/
Questions and comments about this data collection can be directed to: Dr. Edwin V. Bell, II
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Arvydas J. Kliore | Data Provider | NASA Jet Propulsion Laboratory | arvydas.j.kliore@nasa.gov |
Dr. Mitchell K. Gordon | General Contact | m.k.gordon@qmw.ac.uk |