This bundle contains open-loop radio receiver data collected at the Canberra (Australia) 64-m antenna of the NASA Deep Space Network (DSS-43) during the Voyager 1 ingress radio occultation at Saturn on day 1980-318. The data include samples from receiver outputs at S-band (13 cm wavelength) and X-band (3.6 cm) in right-circular polarization. Also included are test measurements collected within a few hours of the Saturn observations. The data supported investigations of Saturn's neutral atmosphere and ionosphere. 13 original data tapes -- known as Original Data Records (ODRs) -- were delivered to the Voyager Radio Science Team in a format that (today) is unknown. This format has similarities to the formats used for the Voyager 1 and 2 encounters at Jupiter the previous year and the Voyager 1 egress occultation at Saturn captured at DSS-63 just a few hours later. Although there are differences with these similar formats, the time and sample data appear to be understood correctly and the data may be suitable for new science analysis. Each original tape forms the basis for a PDS4 product in the bundle. The binary file is the first part of the product. The binary data have been converted to ASCII for easier reading. There is one ASCII table with record header data (to the extent that can be understood from the limited documentation) and two ASCII files with the receiver samples -- one with S-band samples and the other with X-band samples. These are the second, third, and fourth parts of each PDS4 product. Each product also includes a detached PDS4 label file written in XML and a small ASCII file with terse titles for the fields in the header table. For example, the neutral atmospheric occultation began during binary tape VA625. The components of its corresponding product in this archive are: vg1s_43mr_1980318t030501.xml (PDS4 label) va625a.odr (original binary file) vg1s_43mr_1980318t030501.tab (ASCII record headers) vg1s_43mr_1980318t030501.txt (ASCII header titles) vg1s_43sr_1980318t030501.tab (S-band receiver samples) vg1s_43xr_1980318t030501.tab (X-band receiver samples) In one case, a record could not be read from the ODR tape that was delivered to the Voyager Radio Science Team. A replacement record has been substituted as part of the archiving task. Field 6 in the binary replacement record (Field 3 in the ASCII header record) has been set to '2', and the corresponding receiver output samples have been set to '127'. In the files of ASCII samples, all sample values have been reduced by 127 so that the samples are distributed approximately uniformly around zero. Each ODR has been processed to give a pair of 'browse' summary plots, each with a histogram of data sample values, a plot of average sample power versus time, and a plot of time-averaged power spectra. The pair of browse summary plots has been combined with a PDS4 label to create a single PDS4 data product. There are 13 browse products -- one for each ODR product. Also included in the bundle are reconstructions of the spacecraft trajectory and spacecraft high-gain antenna pointing, which was offset during the Saturn atmospheric occultation to compensate for refraction. Estimated frequencies of the spacecraft ultrastable oscillator (USO) are also included. The document collection includes a description of the Voyager mission, a Software Interface Specification (SIS) for the archive bundle, and a description of the high-gain antenna pointing reconstruction procedure. Documentation of the binary formats in the ODR (to the extent that can be inferred from other documentation and from examination of the binary files themselves) is included in the SIS. Note: This information is provided in the bundle's readme.txt
The complete peer review bundle (voyager1_rss_saturn_raw43.tar.gz) is online here. Also provided are the checksum manifest and validation report; these latter two files are primarily for reviewers concerned with PDS4-compliance (see instructions below).
Reviewers should begin by reading the readme.txt file (top level of the bundle). The Software Interface Specification (SIS) is included in the document collection and provides detailed descriptions of the archive bundle.
The directory structure of the PDS4 bundle is illustrated below:
Here are guidelines and some information to help you produce an effective review with a reasonable level of effort.
All reviewers must address two general areas:While it is not realistic for you to analyze every data file, please check enough to convince yourself of the quality and consistency of the data and of any errors that you encounter.
Please also evaluate the documentation provided in individual table labels, and referenced journal articles. Much of the information contained in the referenced articles is not duplicated in the data sets.
Questions for reviewers to address are:
In addition to an overall recommendation, the RMS Node will compile a list of liens in the archive design or sample products/bundle. The liens must be resolved before the associated data set can be archived.
Summary:
43 product(s)
0 error(s)
5 warning(s)
Product Validation Summary:
43 product(s) passed
0 product(s) failed
0 product(s) skipped
43 product(s) total
Referential Integrity Check Summary:
43 check(s) passed
0 check(s) failed
0 check(s) skipped
43 check(s) total
Message Types:
5 warning.label.context_ref_mismatch
warning.label.context_ref_mismatch
Value: 'Equipment' Expected one of: '[Spacecraft]'
These refer to Voyager 1 being described as 'Equipment' rather than 'Spacecraft'. This is because Voyager 1 is the 'target' of spacecraft engineering 'observations'. That is, the onboard engineering system is monitoring the status of the spacecraft. So, even though Voyager 1 is participating in observations of Saturn, the engineering system doesn't know that; its target is the spacecraft itself.
RMS is submitting an SCR to discuss dual use context products for discussion within DDWG and CCB (in-prep).