User's Guide

UPNAV

Process and disseminate navspasur and time correction data.

Function:

Process and disseminate navspasur and time correction data in a production environment.

Parameters:

LOGFILE(--)
Log file. Name of the log file to write all processing messages to. If defaulted, the file "upnav;log" in the ADAPSLOG directory will be used.

Example:

    LAS> UPNAV LOGFILE=[logdir]upnavlog

    UPNAV will process the ephemeris NAVSPASUR files, if any exist. If any were processed, the resultant ephemeris tables will be propagated to all supported systems. Also, the time correction tables will be propagated to all supported systems. Processing messages and errors will be written to "[logdir]upnavlog;log".

Description/Algorithm:

UPNAV searches for and processes the acquired ephemeris NAVSPASUR files. Satrack is called to update the ephemeris data files. The ephemeris data files are propagated to all of the other supported systems. Once processed, UPNAV renames the files to have a "done" suffix. For example, "s4941001_0414.nav" is renamed to "s4941001_0414.done". Files with the "done" suffix are removed from the system after they are 3 days old. UPNAV also propagates the time correction tables to all of the other supported systems.

Nonfatal Error Messages:

  1. [upnav-findf] No files found to process

    No NAVSPASUR files were acquired since the last time UPNAV executed.

Fatal Error Messages:

  1. [upnav-fatal] Fatal error encountered

    A fatal error was encountered, processing is terminated. Refer to the preceding specific error message to determine what action to take.

  2. [upnav-stfail] Error calling SATRACK process

    An error occurred while executing SATRACK. Refer to the specific SATRACK error messages.

  3. [upnav-rnfail] Error renamimg file to .done

    An error occurred renaming the NAVSPASUR file to signify that it has been processed. Check the file permission on the NAVSPASUR file.

  4. [upnav-prfail] Error propagating ephemeris data

    An error occurred sending ephemeris data to the appropriate systems. Ensure the systems are operational.

  5. [upnav-tcfail] Error propagating time correction data

    An error occurred sending time correction data to the appropriate systems. Ensure the systems are operational.

  6. [upnav-clfail] Error cleaning up old files

    An error occurred deleting old NAVSPASUR files. Check the file permission on these files.

  7. [upnav-file] Error finding ephemeris file

    The navspasur ephemeris files could not be found. If the error persists, contact the system administrator.

User Notes:

    1. A description of how the ephemeris data file is made available for UPNAV processing follows:

    The ephemeris data used in AVHRR data processing is obtained daily from the electronic bulletin board of the Naval Space Surveillance Center (NAVSPASUR) in Dahlgren, Virginia. A script on a PC in the ADP Support Section at the EROS Data Center (EDC) executes at approximately 07:15 each morning. This script establishes an electronic connection to the PC at NAVSPASUR and uses KERMIT to download the ephemeris data to the PC at EDC. This ephemeris data is then copied to a PCNFS mounted disk on the SGS4. A script on the EDC SGS4 computer system executes each morning at approximately 09:00. This script appends a date stamp and "nav" suffix to the name of the file. For example, "s4941001" might be renamed to "s4941001_0414.nav". This renaming technique allows each day's ephemeris data to have a unique name which prevents it from being overwritten by subsequent acquisitions. This script resides in the directory /usr/local/bin and is called mv_efemeris.

  1. The shell script upnav.csh does remote copies to target systems with the defined directory structure on the target system to be "ADAPSTABLES". For this reason, the ADAPSTABLES variable must be defined on the target system even when being accessed remotely. Since remote commands ("rcp" in this case) execute the users ".cshrc" file but not the users ".login" file, the ".cshrc" file must initialize the ADAPS environment. The following lines are recommended within the users ".cshrc" file:

        if ((-r /etc/login) && (! $?EDCSOFT)) then
    	source /etc/login
    	eval `$masterlog response comfile LAS70D`
    	unset response
    	unset comfile
        endif