ConstellationList Application

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Description

ConstellationList provides lists of the GPS SV PRN ID active/inactive on a given day. In particular, ConstellationList provides a means of determining which SVs are members of the "Base 24" constellation and which are not. This is usually of no interest to the general user, but is important in cases where programs are evaluating GPS performance against a defined standard such at the Standard Positioning Service (SPS) Performance Standard (PS) which defines GPS performance in terms of the "official" constellation as opposed to the superset which is normally available. The results are provided as a text list of comma separated values on a a single line, suitable for piping into another process.

The complication in this process is that the information regarding the orbit plane/slot of each SV is not available from the broadcast message. It must be obtain "external to the system". Once source of such information is the USCG Navigation Center website which store the Operational Advisories. These advisories provide the relationship between SVs and plane/slot assignments. ConstellationList is programmed to read the advisories as an input format, as long as the format of the advisories does not change.

As an alternative to the Operational Advisories, ARL:UT has prepared files of the assignments for specific years as comma separated value files. Each line in these files represents the status on a given day and includes the mapping between the PRN IDs and the NAVSTAR numbers. These files have been hand-checked and are available in the GPSTk repository as Slot2007.csv and Slot2008.csv.

Command Summary

Required Arguments:
Short Arg. Long Arg. Description
-i --input-file=<arg> The name of the Constellation Definition file(s) to read.
-y --year=<arg> Year of interest.
-j --day-of-year=<arg> Day of year.

Optional Arguments:
-d --debug Increase debug level.
-v --verbose Increase verbosity.
-h --help Print help usage.
-O -OpsAd Assume input file is Op Advisory format (CSV is default).
-b -Base24 List PRNs in Base 24 Constellation.
-x --excessSVs List PRNs in use, but in excess of the Base 24 Constellation.
-n --notBase24 List PRNs NOT used in Base 24 Constellation.
-s --SVN Output Output SVN in place of PRN (not valid for -O).

Usage examples

>ConstellationList -iSlot2008.csv -tC -y2008 -j001 -b
2, 3, 4, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 27, 28, 30, 31
>ConstellationList -iSlot2008.csv -tC -y2008 -j001 -n
1, 5, 7, 24, 25, 26, 29, 32
>ConstellationList -iSlot2008.csv -tC -y2008 -j001 -n
1, 5, 24, 25, 26
>ConstellationList -iSlot2008.csv -tC -y2008 -j001 -b -s
61, 33, 34, 36, 38, 39, 40, 46, 58, 43, 41, 55, 56, 53, 54, 59, 51, 45, 47, 60, 27, 44, 30, 52

Platforms Supported

This application has been successfully used in Linux. This application successfully builds under these environments: linux-x86, linux-x86_64, solaris-ppc, Windows/.net2005, MacOS/X-Code.

-- NicoleQuindara - 05 Aug 2011
Topic revision: r5 - 08 Aug 2011, NicoleQuindara
 

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