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Author Topic: Different WKT definition to EPSG.io  (Read 207 times)

Phogi

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Different WKT definition to EPSG.io
« on: December 03, 2019, 05:28:32 AM »
Hello support,

I find that NAD83(CSRS) / BC Alberts EPSG:3153 in Agisoft has different WKT definition to http://epsg.io/3153.

In Metashape the toWGS84 defined as TOWGS84[-0.991,1.9072,0.5129,0.025789907519493,0.009650098960270401,0.011659943232342,0],

while in EPSG.io it is [0,0,0,0,0,0,0].

Is this a bug or different database for Agisoft referred to?

Thanks!

Phogi

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Re: Different WKT definition to EPSG.io
« Reply #1 on: December 03, 2019, 09:30:43 AM »
Hi Alexey,

I also notice that for this projection it seems the coordinate transformation is not correct, conversion seems wrongly added based on the EPSG.io's transformation.

For example, a point in EPSG: 3153 (1213336.088, 465211.399, 3.368) (E/N/H) converted to WGS84

in Agisoft will return [-122.30268840679987, 58.556709548457782, 3.2393043], (Already outside of Alberta area!)

in epsg.io will return [-123.0771235,49.1635985].

So there's something wrong with the conversion tool!
Could you take a look and check if this will be fixed?

Thank you!

Alexey Pasumansky

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Re: Different WKT definition to EPSG.io
« Reply #2 on: December 03, 2019, 03:16:25 PM »
Hello Phogi,

You can select the transformation parameters from the list of available EPSG transformations for this system in Datum transformation settings dialog. The default transformation is EPSG:1946, but you can switch to a different one, for example, EPSG::1842 which is [0,0,0,0,0,0,0].
Best regards,
Alexey Pasumansky,
AgiSoft LLC

Alexey Pasumansky

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Re: Different WKT definition to EPSG.io
« Reply #3 on: December 03, 2019, 05:42:25 PM »
Meanwhile we have checked the coordinate system and it appears that there was an issue with the proper calculation of the Albers Equal Area projection parameters. The fix will be included in the next version update.
Best regards,
Alexey Pasumansky,
AgiSoft LLC

Phogi

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Re: Different WKT definition to EPSG.io
« Reply #4 on: December 09, 2019, 01:12:45 AM »
Thank you Alexey!