Different EPSG values

[D__SamuelRajasekhar]

Hello All,

I got a geo-TIFF with

Projection: UTM
Datum:      WGS84
Zone:       18
The EPSG Code is 32617

I Re-projected the same image to NAD83

Projection: UTM
Datum:      NAD83
Zone:       18
The EPSG Code is 26918 (correct)

Does any one know why this discrepancy occurs?
I heard that ESRI not current with EPSG processing or something like that.

Thanks,
Samuel

[MelitaKennedy]

While Esri does trail the EPSG Dataset because of release cycles, EPSG:32617 has been 32617 for a very long time and has never had any changes. If you dump the geotiff headers with listgeo.exe or something similar, are the projection parameters there? Do they match the EPSG code or the listed zone? Did Esri software create the geotiff?

Melita

[D__SamuelRajasekhar]

Hello Melita,

The geo-referenced aerial photographs  (JP2 format) were probably created by ESRI software (by Vendor). The Projection should have been UTM NAD83 Zone18. Instead for some reason few were re-sampled to UTM WGS84 Zone 17. Re-projecting it solved the issue.

[ATTACH=CONFIG]33304[/ATTACH]

[ATTACH=CONFIG]33305[/ATTACH]

Thanks,
Samuel

[D__SamuelRajasekhar]

Also in ArcMap the same image is describes as Zone 17 when in fact it was in Zone 18.

[ATTACH=CONFIG]33306[/ATTACH]

Thanks