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RT-STPS Notes
Some notes on RT-STPS to be used in future.
Aggregated notes on RT-STPS for future notes;
From http://directreadout.gsfc.nasa.gov/index.cfm?section=portal%20info&page=faqs_subject&topic=RT-STPS
| 06-Mar-03 Please explain the default filename format produced by the Sorcerer node? |
| Files containing a PDS have names that consist of 40 ASCII characters, defined as follows: Character 1 = "P" for a PDS. Characters 2 - 8 refer to the first APID in the data set. The first 3 characters are the 3-digit spacecraft ID number (= "042" for Terra, "154" for Aqua). The second four characters are the 4-digit application ID number (= "0064" FOR MODIS). Both numbers are right justified, and left filled with zeroes as necessary. Characters 9 - 15 give the SCID and APID for the second APID in the data set. If data set does not contain a second APID, then these 7 characters are set to "AAAAAAA". Characters 16 - 22 give the SCID and APID for the third APID in the data set. If data set does not contain a third APID, then these 7 characters are set to "AAAAAAA". Characters 23 - 33 give the GMT/ZULU time of EDS/PDS creation (i.e. receipt of the signal at the ground), in YYYYDDDHHMM format, where YYYY = year, DDD = day number of year, HH = hours, MM = seconds Character 34 is a numeric identifier, ranging from "0" to "9". It is a one-up, wrap around, data set counter. Characters 35 and 36 refer to the file number. Every PDS resides in two or more files. The first file (file number "00") always stores the construction record by itself. The one or more time-ordered files thereafter sequentially store the SDUs (file numbers "01" through "99"). Characters 37 - 40 = ".PDS" for a PDS. |
| 06-Mar-03 Where can I find documentation on the MODIS L0 format that is output from the RT-STPS? |
| The
MODIS Level 0 format is defined in section 8 of the January 23, 1998
ICD between EDOS and EGS. This is not specificly a MODIS document, but
generally applies to all application IDs. A "production data set" (or PDS) consists of two or more files. The first file is called the construction record and can be considered a binary shipping letter. The ICD will break down its format. The remaining files are a succession of data files containing back-to-back packets. Usually there is only one data file, but the spec says it is not required. A PDS can contain packets from up to 3 different application IDs. In practice though, a PDS will have only one appid and only one data file. The packets in the MODIS data file have no additional headers or trailers; they are pure back-to-back packets. However, some other applications may create PDS files that do have annotation (usually frame times). The RT-STPS code does not do this. The ICD is available on-line under "Mission Support: Terra" at http://directreadout.gsfc.nasa.gov/documents/satellite_gen/cdrlb301.pdf . Detailed information about the MODIS Level 0 format specifically can be found in Appendix C of the MODIS Users' Guide. This document is also available on-line under "Mission Support: Terra" at http://directreadout.gsfc.nasa.gov/documents/satellite_gen/MODIS_UG.pdf . |
See also,
http://directreadout.gsfc.nasa.gov/
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