Weighted station selection (SELSTA)

This procedure is used to select a sub-file from a set of normal equation files for use in a subsequent weighted station adjustment. The file is used as a constraint for a network which derives its control from the previously adjusted framework. For example the primary network can be used to control a city network. The portion of the primary network that affects the city network is abstracted from the primary files as a weighted station file and used as constraint for the city network.

The user is asked to select a subset of stations. These pairs are selected as

1. Within a radius with center as a station or an input coordinate
2. Within a window as defined by a series of vertices
3. Selected stations
4. A combination of the above

The program reports the number of stations and requests either to continue with the computation, quit or repeat the selection process.

The user is queried for a filename with which to store the resultant weighted station adjustment file. A CR will delete the file.

 Example.

 
 cd /data/sudbury      <-- Go to data directory
 SELSTA                <-- Execute the procedure
                        The user is queried for options
                        as described above.

Batch processing (VAX)

For batch processing the user must save the sequence of requests in a file which is entered as a parameter on the submit command.

The file might look like this on the sub-directory (without comments!!)

 W                <-- Select the stations by a window
 45,90            <-- Enter vertice
 46.2033,91.21444 <-- Enter vertice (dd.mmsss)
 999,999          <-- End vertices
 Q                <-- Continue with computations
 S                <-- Save the station adjustment file
 

The user enters the parameters in the batch procedure

        SUBMIT/PARAMETER=(DATA.SUDBURY,par,SAVSTA)/NOPRINT GHOST$CMND:SELSTA

 where DATA.SUDBURY is the sub-directory for the files.
       par          is the parameter file
       SAVSTA       is the filename for the station
                       adjustment file 

      ' Window           [W]',selw
      ' Radius           [R]',selr
        '  Enter radius for selecting stations (kil)'
        ' Enter center for radius',radius
       
      ' Select station    [S]'
      ' Select coordinate [C]'
       ' Menu          [CR][M]'
      ' Station number   [S]',sels
        ' Station number     [N]'
        ' Choose from list   [C]'
                 ' Next station        [C/R]'
                 ' Menu                  [M]'
                 ' Finished selection    [F]'
         ' File of stations   [F]'
            ' Select a file of station numbers '
            ' Number in column 1-9'
      
 
     ' Weighted Station adjustment '
      ' Found ',npos,' unknowns'
      ' '
      ' Repeat selection                [R]'
      ' Write WSA to code 97 ONLY       [W]'
      ' Write WSA and covariance       [CR]'