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Author Topic: Selected transformation is not supported (convert using custom PRJ)  (Read 2121 times)

csay12

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Hi,

I'm trying to convert photos with GPS EXIF data to a local coordinate system defined by the attached PRJ. When I try to convert, I keep running into a "Selected transformation is not supported" error. Any ideas?

Thanks!

Alexey Pasumansky

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Re: Selected transformation is not supported (convert using custom PRJ)
« Reply #1 on: November 21, 2017, 10:04:37 AM »
Hello csay12,

The conversions between the coordinate systems on different datums in PhotoScan are performed via WGS84, so it is necessary to specify TOWGS84 parameters in the coordinate system definition.

Please try the following projection:
Code: [Select]
PROJCS["NAD83(HARN) / CCD Local (US foot)",
GEOGCS["NAD83(HARN)",
DATUM["NAD83 (High Accuracy Reference Network)",
SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],
TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6152"]],
PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],
UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9102"]],
AUTHORITY["EPSG","4152"]],
PROJECTION["Transverse_Mercator",AUTHORITY["EPSG","9807"]],
PARAMETER["latitude_of_origin",39.75527777777778],
PARAMETER["central_meridian",-104.8980555555555],
PARAMETER["scale_factor",1.00025403],
PARAMETER["false_easting",600000],
PARAMETER["false_northing",400000],
UNIT["US survey foot",0.3048006096012192,AUTHORITY["EPSG","9003"]]]

In case you need to correct some parameters in the GEOGCS section, then remove corresponding AUTHORITY subsections, otherwise, PhotoScan will use the parameters according to EPSG definition and will ignore the modified values.
Best regards,
Alexey Pasumansky,
Agisoft LLC