NSSDCA ID: PSPG-00887
Availability: At NSSDC, Ready for Electronic Access
This description was generated automatically using input from the Planetary Data System.
This data set contains 243 Archival Tracking Data Files (ATDFs) and 6 Orbit Data Files (ODFs) from the MAGELLAN mission to Venus. The ATDFs were collected at Earth stations of the NASA Deep Space Network (DSN) from May 1989 (as MAGELLAN began its cruise to Venus) until October 1994 (after the MAGELLAN 'termination experiment'). ODF coverage is only from April 1992 to end of mission; ODFs were reconstructed from NAVIO files (an in-house format at the NASA Jet Propulsion Laboratory, JPL). The data have been used to derive spherical harmonic models of the Venus gravity field [KONOPLIVETAL1999][KONOPLIV&SJOGREN1996]. The models can be obtained from the NASA Planetary Data System (PDS), where they are part of data set MGN-V-RSS-5-GRAVITY-L2-V1.0. Parameters ========== ATDFs and ODFs contain measurements of range between the Earth station and MAGELLAN spacecraft, Doppler shift of the carrier frequency, carrier signal strength, and ground station azimuth and elevation angles. They also contain many ground station configuration parameters. The ODF is an edited and compressed (time integration) version of the ATDF. The ODFs in this archive are aggregations covering about one year each (1992, 1993, and 1994). Processing ========== ATDF data were collected using one or more DSN closed-loop receivers, which reported frequency and amplitude of the MAGELLAN carrier signal at a rate (typically) of 10 times per second. When a coded (ranging) subcarrier was used, a correlator estimated round-trip time between Earth and spacecraft, which can be interpreted as two-way distance. The file of measured values was screened manually, and 'bad' measurements were removed. There has been no other ATDF processing. ODF files are usually derived from one or more ATDFs. The MAGELLAN ODFs were reconstructed from NAVIO files (an internal JPL format). In addition to being edited versions of ATDFs, these ODFs contain averaged values of observation parameters -- both 2- and 10-second averages are available (in separate files). Data ==== The archive comprises 243 ATDFs, 6 ODFs, and supporting documentation on the structure and content of the ATDF and ODF. Ancillary Data ============== Also included in the data set are four data types that may be used to calibrate the radio tracking measurements. Angular Momentum Desaturation (AMD) files -- also known as Small Forces Files -- are included in the AMD directory. Media calibration files for ionospheric and tropospheric effects are in the ION and TRO directories, respectively. Local weather conditions at the NASA DSN complexes are stored in the WEA directory. Coordinate System ================= The radio data are not strongly dependent on coordinate systems. Ground antenna azimuth and elevation are in an unknown local frame; but it is the range and Doppler measurements which are most important and those are independent of the coordinate system chosen. Software ======== No software is included with this archive. Media/Format ============ This archival data set were delivered to the PDS Geosciences (GEO) Node on three DVD+R discs. They will be distributed electronically.
These data are available on-line from the Planetary Data System (PDS) at:
http://pds-geosciences.wustl.edu/mgn/mgn-v-rss-1-tracking-v1/MG_2601/
Questions and comments about this data collection can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Jon M. Jenkins | Data Provider | NASA Ames Research Center | jjenkins@mail.arc.nasa.gov |
Dr. Richard A. Simpson | General Contact | Stanford University | rsimpson@magellan.stanford.edu |