GEOTRANSFORMER

Basic Information

Name of Program

GEOTRANSFORMER

Version-Date

September 2015

Description-Date

September 2015

Catchwords

coordinate transformation
coordinate system
Gauss-Krueger
European Terrestrial Reference System 1989 (ETRS89)
world geodetic system 1984 (WGS84)
european datum 1950 (ED50)
Potsdam datum (Bessel 1841)
Krassovski ellipsoid
NTv2 method
GNTRANS-WSV
BETA2007
Rijksdriehoeksmeting (RD, coordinate system of the netherlands)
universal transverse mercator (UTM)
European petrol service group (EPSG)

Short Description of Functionality

This program transforms coordinates between different coordinate systems. Currently implemented coordinate systems are:

• Gauß-Krüger (stripe 2 to 5)
• spherical coordinates (longitude, latitude)
• Universal Transverse Mercator (UTM)
• Rijksdatum (Netherlands)
• local metric central projection

Currently implemented geodetic 7-parameter transformations:

• European Terrestrial Reference System 1989 (ETRS89)
• World Geodetic System 1984 (WGS84)
• European Datum 1950 (ED50)
• Federal Intstitute for cartography und geodesy, standard parameter
• Federal Intstitute for cartography und geodesy, latitudes >52,3 degrees N
• BAW C. Maushake,
• Krassovsky standard (Wikipedia)
• Krassovsky (WSA Stralsund)
• Federal Intstitute for cartography und geodesy, latitudes between 50,3 degrees N and 52,3 degrees N
• Federal Intstitute for cartography und geodesy, latitudes <50,3 Grad N

Additionally the NTv2 grid shift method is provided for datum transformation of DHDN90/STN to ETRS89 and back, based on GNTRANS-WSV or BETA2007.

Input-Files

1. triangulated mesh (file type TICAD,gitter05.dat/bin)
2. digitized polylines (file type digi.gkk) or
3. digitized polylines (file type insel.dat) or
4. polygon file (file type poly.dat) or
5. polygone file to protect edges of a grid (file type nodes.save) oder
6. plot frames (file type frames.dat, center and size, or
7. description of boundary cells (file type rgz.dat) or
8. ASCII triple data, file with soundings (file type geom.dat) or
9. time series at single station (file type boewrt.dat) or
10. position description (file type geopos.dat) or
11. triangulated UNTRIM-VC mesh (file type untrim_grid.dat, version Vincenzo Casulli) or
12. grid of the numerical method DELFT3D (file type delft3d.grd) or
13. triangulated UNTRIM-BAW mesh (file type untrim_grid.dat, BAW version) or
14. system file for specific locations (file type location_grid.dat) or
15. file IPDS to initialize models area wide (file type ipds.dat) or
16. world files which describe the georeference of an Image (typical file extensions are .pngw, .jpgw, .gifw) or
17. mesh of profiles (file type profil05.bin) .

Output-Files

1. triangulated mesh (file type TICAD,gitter05.dat/bin)
2. digitized polylines (file type digi.gkk) or
3. digitized polylines (file type insel.dat) or
4. polygon file (file type poly.dat) or
5. polygone file to protect edges of a grid (file type nodes.save) oder
6. plot frames (file type frames.dat, center and size, or
7. description of boundary cells (file type rgz.dat) or
8. ASCII triple data, file with soundings (file type geom.dat) or
9. time series at single station (file type boewrt.dat) or
10. position description (file type geopos.dat) or
11. triangulated UNTRIM-VC mesh (file type untrim_grid.dat, version Vincenzo Casulli) or
12. grid of the numerical method DELFT3D (file type delft3d.grd) or
13. triangulated UNTRIM-BAW mesh (file type untrim_grid.dat, BAW version) or
14. system file for specific locations (file type location_grid.dat) or
15. file IPDS to initialize models area wide (file type ipds.dat) or
16. world files which describe the georeference of an Image (typical file extensions are .pngw, .jpgw, .gifw) or
17. mesh of profiles (file type profil05.bin) .

Methodology

• Input and output list are opened at the same time. Every coordinate point will be read, transformed and written on the output list immediately. So the size of the input file is unlimited. Comments and other informations are copied "as is"!
• The formatting of decimal coordinates depends on the actual projection of coordinates (geographic or map coordinates). File type 08 (ASCII triple data) allows user defined Output Format via Environment variable GEOMFMT.
• The program first calculates spherical coordinates (WGS84) from input projected coordiantes. Then the new geodetic datum and projection is applied. In the datum cases DHDN or STN in input and/or output data, the NTv2 method with grid shift file *.gsb is provided as Default alternative. The program should be used with the actual NTv2 grid shift files provided by the GNTRANS-WSV System conform to this system. It can be used with the BETA2007.gsb file to get conformity with the ATKIS system.
• on input in files of type 08 (geom.dat) the separators semicolon, comma and colon are allowed.
• on input in files of type 09 (boewrt.dat) or 10 (geopos.dat), 13 (untrim_grid.dat, BAW version) and 14 (location_grid.dat) the coordinate reference system is first changed to the input system, if an internal CRS Information is available. In files of type 01 (gitter05.dat), 02 (digi.gkk) and 08 (geom.dat) the( well known!) coordinate reference system of the input files can be specified through the comment "C CRS=#####" at the beginning of the file. "#####" here is an EPSG code which is supported by libgeodesy. In this case also a Transformation to the input system is done first. The input system must have a valid EPSG code too.
• in input files of type 16 (world files) also the avarage pixel width and height transformation parameters are changed by assuming a virtual image of 800x800 pixels.
• To all ASCII formats which are not NAMELIST based, a file header with the current coordinate information is added as comments.
• UTM easting coordinates with 7 and 8 digits are recognized and changed into 6 digits representation. For recognition of valid 8 und 7 digits easting values both the number of digits and the actual UTM zone are used.

EPSG codes wich are supported by libgeodesy are:

• Gauss-Krueger 3 degree / DHDN: EPSG 31466-31469 (EPSG = 31464 + stripe number)
• Gauss-Krueger 3 degree / STN : EPSG 02398-02399
• UTM / ETRS89  : EPSG 25828-25838 (EPSG = 25800 + zone number)
• UTM / ED50  : EPSG 23028-23038 (EPSG = 23000 + zone number)
• UTM / WGS84  : EPSG 32601-32660 (EPSG = 32600 + zone number)
• RD Amersfoort New  : EPSG 28992
• Geographic ETRS89  : EPSG 4258
• Geographic WGS84  : EPSG 4326
• Geographic ED 50  : EPSG 4230
• Geographic DHDN  : EPSG 4314

It is reccommended, to store the coordinate reference system as an EPSG code inside the basic datasets (raw data), if it is known. This can be done by the "magic comment" inside the most ASCII file types. Within file types, where storage is foreseen for an EPSG code, it should be placed there.

Actual datasets should be stored with UTM/ETRS89 coordinates of the valid zone or in geographic coordinates (ETRS89 or WGS84) . Transforming older datasets with Gauß-Krüger coordinates into UTM/ETRS89 should be done preferably with the NTv2 method after GNTRANS-WSV. The transformation grid is valid only for German area including coastal waters. Coordinates outside this area must not be transformed by NTv2 but should be transformed using a valid Helmert transformation parameter set.

Transforming coordinates is not a trivial task. Therefor the result of the transformation should be tested for correctness and usability.

Program(s) to run before this Program

all programs wich use above listed file formats

Program(s) to run after this Program

all programs wich use above listed file formats

Additional Information

Language

Fortran95

Additional software

NTv2 grids dhdn_to_etrs89_wsv_v1.gsb, stn_to_etrs89_wsv_v1.gsb and BETA2007.gsb

Original Version

G. Seiß (main program, file I/O, libgeodesy)

Maintenance

G. Seiß

Documentation/Literature

interactive dialog, self explaining
$PROGHOME/examples/geotransformer
Junkins, D.R. and Farley, S.A. (1995) National Transformation version 2 Users Guide, Geodetic Survey Division Geomatics Canada

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