Changes between Version 8 and Version 9 of Processing/Applanix


Ignore:
Timestamp:
Sep 19, 2007 1:10:37 PM (12 years ago)
Author:
mggr
Comment:

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  • Processing/Applanix

    v8 v9  
    3434== UK Rinex base stations ==
    3535
     36For the UK Rinex stations, the position is provided as Earth-centered Cartesian coordinates (XYZ) in the ETRS89 datum (directly compatible with WGS-84, just more exacting).  As they're compatible, these coordinates just need to be converted to WGS-84 lat/longs for POSGPS.  If we were coming from or going to a different datum/coordinate system (e.g. OS National Grid), we would need to do a coordinate transformation rather than conversion - this is complicated!
     37
    3638For the O/S UK GPS network (Rinex format files), the .07o file has a header like this:
    3739{{{
     
    5860
    5961The `APPROX POSITION XYZ` is the precise ETRS89 X,Y,Z location (see COMMENT sections to confirm this it says it's precise).  This must be converted to a WGS-84 lat/long:
    60  1. Go to http://gps.ordnancesurvey.co.uk/etrs89geo_natgrid.asp
    61  1. Click the pretty pink 'ETRS89 xyz' button
    62  1. Enter the coordinates from the `APPROX POSITION` field in the .07o file
    63  1. Convert to National Grid
    64  1. In POSGPS, enter these grid coordinates (using Grid: British Grid)
    65 
    66 WRONG!  need to convert, not transform. saving for tonight
     62 1. Go to http://www.ordnancesurvey.co.uk/oswebsite/gps/information/coordinatesystemsinfo/gpsspreadsheet.html and get the coordinate conversion spreadsheet
     63 1. Enter the coordinates from the `APPROX POSITION` field in the .07o file into the XYZ fields on the Enter Coords here sheet, clearing the other fields
     64 1. Check the constants are set for WGS-84
     65 1. Take the lat/long/ellipsoidal height from the ''XYZ to lat,long,H'' sheet and enter into POSGPS (you may want to save these as a favourite too)
    6766
    6867-----------