The CSV station file holds a list of station codes, coordinates, and other information in a generic delimited text file format. The file is organised in named columns, and a format definition file specifies which column contain which data (ie which column holds the station code, which the coordinates, and so on.).
The station file is loaded into SNAP using a coordinate_file command, which include the CSV format options, in particular the option "format=dtf_file" which specifies the format definition file to be used.
The CSV options may also specify other options used in the format definition file, for example the coordinate system.
As an example, the format definition file "mdfc1.dtf" could contain:
FORMAT CSV HEADER=Y code @CODE name @ALTN coordinate_system $crdsys default "NZGD2000" height_type "ellipsoidal" longitude @ORDV2 latitude @ORDV1 height @ORDV3 classification Order CROD classification_columns MRKS MRKT EXMK
and the corresponding station file "survey_marks.csv" might contain:
CODE,MRKS,MRKT,EXMK,DISTRICT,CROD,ORDV1,ORDV2,ORDV3,NAME,ALTN,COMM BU34,COMM,PIN,Y,AK,2k4,-36.41330980,174.66985338,151.124,SM 6670 SO 62140,, C5MH,COMM,IT,Y,AK,2k5,-36.41132630,174.67215746,154.516,IT 6669 SO 62140,, C5MK,COMM,PIN,Y,AK,2k5,-36.40811060,174.67166544,140.672,SM 6667 SO 62138,, DLL1,COMM,IT,Y,AK,2k5,-36.08821930,174.58516524,53.222,IT V DP 121860,, DLLL,COMM,LP,Y,AK,2k5,-36.08268446,174.59231978,54.141,LP I SO 60868,, DMJN,COMM,LP,Y,AK,2k5,-36.08233021,174.58922847,47.868,LP IV SO 61281,, EH91,PEND,IT,N,AK,2k5,-36.41276352,174.66686644,149.662,IT 1 DP 402188,, EHJJ,PEND,IT,N,AK,2k5,-36.08235914,174.58640631,109.763,IT I DP 339335,, WHNG,COMM,OTHR,Y,AK,2k0,-35.80377146,174.31456670,172.815,Whangarei GPS,,
This would be loaded into SNAP with a command:
coordinate_file survey_marks.csv csv format=mdfc1