User's Guide

NAVSPASUR

Process ephemeris data.

Function:

Reformat the user specified ephemeris data and write it to a standard ephemeris data file. Equatorial crossing information can also be calculated and displayed.

Parameters:

SATID
Satellite number


  = 15427: NOAA-09
  = 16969: NOAA-10
  = 19531: NOAA-11
  = 21263: NOAA-12
  = 23455: NOAA-14
  = 25338: NOAA-15
  = 26536: NOAA-16
  = 27453: NOAA-17
  = 28654: NOAA-18
  = 33591: NOAA-19
  = 29499: METOP-2 

ORBIT
Orbit number. The satellite orbit number (e.g., 12181)

MEANAN
Mean anomaly. Entering "21966907" signifies .21966907 revolutions.

MEANMO
Mean motion. Entering "82840512" signifies .82840512 radians/herg.

ODECAY
Orbital decay. Entering "00060" signifies .0006 1.E-5 radians/herg squared.

ECCENT
Eccentricity. Entering "00121013" signifies a value of .00121013

ARGPER
Argument of perigee. Entering "97265103" signifies a value of .97265103 revolutions.

LONGASC
Longitude of ascending node. Entering "59806393" signifies a value of .59806393 revolutions.

INCLINE
Inclination. Entering "27503749" signifies a value of .27503749 revolutions.

EPDATE
Date of epoch. Epoch is at 00:00:00 GMT. Enter using the format "YYMMDD".

PRINT(--)
Output destination. This output contains the equatorial crossing, the time of ascending node, and the orbit number for each of the orbits.


  = --:        No report.  No equatorial crossing
               report will be generated.
  = TERM:      Terminal.  Output is sent to the
               user's terminal.
  = LP:        Line printer.  Output is sent to the
               printer defined by $PRINTER.
  = Filename:  User-supplied filename.  Output is
               sent to the user-supplied file with
               the extension .prt.

Example:

    LAS> NAVSPASUR SATID=16969 ORBIT=12181 MEANAN=21966907 MEANMO=82840512 ODECAY=00060 ECCENT=00121013 ARGPER=97265103 LONGASC=59806393 INCLINE=27503749 EPDATE=910205

    The above input parameters are used to update the ephemeris data file "16969.dat" in ADAPSTABLES. The equatorial crossing information will not be calculated.

Description/Algorithm:

The user-specified ephemeris information is formatted and written to a standard ephemeris data file. This data file is composed of ephemeris data records which are sixty-nine characters long. The name of the appropriate ephemeris data file consists of the satellite ID number with a ";dat" suffix, and resides in the ADAPSTABLES directory. If the information already exists within the appropriate file, the file will not be updated. Equatorial crossing information may be computed and printed to a device specified by the user.

Nonfatal Error Messages:

  1. [put_navsp-dup] Duplicate record found on date <xxxx> in file <xxxx>

    A duplicate record was found in the ephemeris data file, the duplicate record is ignored.

Fatal Error Messages:

  1. [navspasur-fatal] Fatal error encountered

    A fatal error was encountered. A more descriptive message immediately precedes this message.

  2. [navspasur-outopn] Error opening output file

    Check the permissions of the path and file to be opened.

  3. [put_navsp-inread] Error reading input file

    Check the permissions of the path and file to be read.

  4. [put_navsp-inseek] Error seeking input file

    Check the permissions of the path and file.

  5. [put_navsp-write] Error writing data to file

    Check the permissions of the path and file in which the writing is being attempted.

  6. [put_navsp-locf] Error locating file

    The specified file does not exist or does not have the proper file permissions set.

User Notes:

  1. The ephemeris data files updated by NAVSPASUR are located in ADAPSTABLES and have names consisting of the satellite ID number with a ";dat" suffix (e.g., "15427;dat").

  2. A related module is SATRACK. SATRACK is used to update the same ephemeris data files that NAVSPASUR updates. SATRACK reads its input from a file, whereas NAVSPASUR retrieves its input from the user.

  3. Some of the input parameters refer to a "revolution" which is equal to 2 PI radians. Also, some of the input parameters refer to "radians/herg" where 1 herg equals 806.81359 seconds.