NSSDCA ID: PSFP-00662
Availability: Archived at NSSDC, accessible from elsewhere
This description was generated automatically using input from the Planetary Data System.
This data set contains raw and partially processed data from observations of Magellan radio transmissions while the signal was passing through the solar corona. Scintillations on the signal can be related to structure and motion of the coronal material [WOO1993]; polarization of the signal can be used to infer magnetic field within the plasma. Data were acquired using stations of the NASA Deep Space Network (DSN). The Magellan spacecraft transmitted signals that were 100 percent linearly polarized at 13 cm and right-elliptically polarized at 3.6 cm. During summer 1992, when Magellan was in solar superior conjunction, the spacecraft came within 0.6 solar radii of the Sun's center when viewed from Earth. Included in this data set are over 1000 files of raw samples acquired using DSN open-loop receivers and recorders, often in two orthogonal circular polarizations at both wavelengths. The data set spans several months, centered on the superior conjunction date of 1992-06-13. Parameters ========== Each open-loop data file (data type ODR) contains a header followed by several thousand 8-bit sample values from 1-4 receiver output channels. The header gives the time of the first sample, the antenna through which the data were collected, channel assignments, the local oscillator frequency of the receiver, rms values of each receiver output, status and condition flags, and other data useful for interpreting the receiver samples. The samples were obtained coherently from one or more of the following receiving systems: X-RCP 3.6-cm right circularly polarized S-RCP 13-cm right circularly polarized X-LCP 3.6-cm left circularly polarized S-LCP 13-cm left circularly polarized Each 8-bit sample represents the band-limited voltage output of one of the receivers above; individual samples were written to the data file, usually in the order given above. Samples could be collected at rates varying from 100 to 50000 per second from each receiver. The number of samples in each record varied depending on the sampling rate and number of channels being collected. Processing ========== Samples from parallel analog-to-digital converters were stored in buffers until the correct number had been accumulated. Header information was accumulated separately. When the sample buffer was filled, the samples were combined with the header data and the record was written to tape. RMS values of receiver outputs were included in the header. There was no other processing of the data. Data ==== ODR files have names of the form ydddhhmm.ODR where y is the least significant digit of the year, ddd is the 3-digit dayof-year, hh is the hour, and mm is the minute on which data acquisition began. Each ODR file is accompanied by a detached PDS label with name ydddhhmm.LBL. Each label fully describes the format and content of the corresponding data file. There are 1035 ODR files in this data set. Ancillary Data ============== None. Coordinate System ================= Not applicable. Software ======== Software for parsing, reducing, and analyzing data such as these has been developed at the Jet Propulsion Laboratory, Stanford University, and elsewhere. Because parsing must be done at the bit level, its implementation may be very sensitive to platform and operating system. No parsing software has been written and tested on a variety of platforms, so none has been included with the archival data set. Users are referred to PDS labels for detailed information on file formats. Media/Format ============ The archival data set is written on DVD-R media. Each DVD-R volume conforms to ISO 9660 standards.
These data are available on-line from the Planetary Data System (PDS) at:
https://pds-ppi.igpp.ucla.edu/data/MGN-SS-RSS-1-ODR-OPENLOOP-SW-SCINT-V1.0/
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 |