User's Guide

NORAD

Calculate satellite information for the Antenna Control Unit.

Function:

Information from two-line NORAD data is used to generate a file containing formatted satellite information. This file will be transferred to the Antenna Control Unit (ACU) for satellite tracking.

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

EPOCHYR
Epoch year (Last 2 digits of year).

EPOCHDY
Epoch day (Julian day).

EPOCHFD
Epoch fractional day (Decimal point assumed).

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

RTASCEN
Right ascension of the ascending node.

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

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

MEANAN
Mean anomaly. Entering "21966907" signifies a value of .21966907 revolutions.

MEANMO
Mean motion. Entering "82840512" signifies a value of .82840512 radians/herg.

PRINT(TERM)
Output destination. This output contains the input NORAD parameters (satellite data), the output orbital parameters, and the calculated Antenna Control Unit string.


  = 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> NORAD SATID=15427 EPOCHYR=91 EPOCHDY=129 EPOCHFD=02874389 INCLINE=56402 RTASCEN=833494 ECCENT=0012654 ARGPAR=426871 MEANAN=3175986 MEANMO=14121273 PRINT=LP

    The above input parameters are used to calculate the orbital radius, the orbital inclination, the nodal period, the ascending node, the nodal time, and the nodal time correction. A report will be written to the line printer containing this information, the input parameters, and a string which can be used as input to the ACU.

Description/Algorithm:

NORAD generates a file of satellite information to be transferred to the ACU.

The user-specified parameters are retrieved and calculations are made using this information to derive values relating to the nodal period and the orbital radius. The nodal time is calculated from the epoch fractional day. A string to be used by the ACU is also generated. This output is sent to a user-specified file, the line printer, or the terminal.

Nonfatal Error Messages:

    None.

Fatal Error Messages:

  1. [norad-fatal] Fatal error encountered

    A fatal error was encountered. A more descriptive message was displayed immediately preceding this message.

  2. [norad-outopn] Error opening output file

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

User Notes:

  1. A related module is SATRACK. SATRACK is used to generate Antenna Control Unit information much like NORAD. NORAD retrieves user-specified parameters for input data, whereas SATRACK reads input data from a file.

  2. 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.