23.3.1 USER

[SIMULATE\]ARRAY USER Name

Select a User defined array of given Name. The array characteristics are given in a file named user-name.cfg (e.g. user-myarray.cfg for ARRAY USER myarray) in the current directory. The user-name.cfg file format is one of the following two:

 ! Comment:  Strict format for the 8 next lines
 ! RADIUS    = 50
 ! ALTITUDE  =   5056.8
 ! LONGITUDE =  -67.754929
 ! LATITUDE  =  -23.022886
 ! DIAMETER  =   7.0
 ! NBANT     =   12
 ! MODE      =  OBS
 ! Station Name, Lx, Ly, Lz, Diameter [Projected X,Y]
 S1 -94.3216443918 -9.40511363968 -534.35663 7.000000 528.683514053 -9.40511363968
 S2 -95.8628780895 -17.3837237689 -538.00854 7.000000 532.647319322 -17.3837237689
 N3 -98.0478617896 -10.2550947476 -543.18437 7.000000 538.265432235 -10.2550947476
 etc...

 ! Comment:  Strict format for the 8 next lines
 ! RADIUS    = 20000
 ! ALTITUDE  = 2124
 ! LONGITUDE =  -107.6183
 ! LATITUDE  =   34.0783
 ! DIAMETER  =  18
 ! NBANT     =    104
 ! MODE      = GEO
 ! Lx, Ly, Lz, Diam Ants, StationName [ Projected Baseline ]
     -1603217.405612380011    -5041103.852618369274     3555218.077263070736  18  c001
     -1602984.612757581752    -5041124.814699964598     3555293.476251701824  18  c002
     -1603110.687897497322    -5041182.198700777255     3555155.372975168284  18  c003
 etc...

where each line indicates a station name and coordinates. The two accepted format only differ in the MODE indicator that indicates how station coordinates are defined.

In MODE OBS ("OBServatory"), coordinates are relative to the array center specified by its longitude and latitude. In MODE GEO ("GEOcentric"), coordinates are relative to the earth center. Mode OBS is in general better suited for small arrays, while mode GEO is appropriate for large arrays, e.g. the VLA or the future ngVLA.

Besides the user-name.cfg file, user-name-c1.cfg, user-name-c2.cfg, etc... files specify the coordinates of the antennas in each of the named c1, c2 ... configurations of this user-defined array. These files have the same format as the user-name.cfg one, but only contain the relevant station coordinates. RADIUS indicates the array maximum radius for each configuration, just for display. ALTITUDE is in meters, LONGITUDE and LATITUDE are in Degrees. DIAMETER is the antenna diamater. NBANT, the number of antenna station pads, is unused.

See gag_data:user-aca.cfg gag_data:user-aca-c1.cfg and user-aca-c2.cfg for an example.