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Home - General / All posts - Projection issue - OGRIP (ohio imagery)
cycloxslug71 post(s)
#02-Apr-24 21:28

I'm using imagery from OGRIP - a public aerial imagery repository (example file available here: https://gis1.oit.ohio.gov/ZIPARCHIVES_III/IMAGERY/6INGEOTIFF/_ENHANCED/WAR_2023/AS15420552.zip)

Images open fine in QGIS and are properly located. Files imported into Manifold 9 end up placed in Massachusetts, despite seemingly successfully recognizing the projection from the metadata. What am I doing wrong?

<horizsys>

<planar>

<mapproj>

<mapprojn>NAD 1983 HARN StatePlane Ohio South FIPS 3402 Feet</mapprojn>

<lambertc>

<stdparll>38.73333333333333</stdparll>

<stdparll>40.03333333333333</stdparll>

<longcm>-82.5</longcm>

<latprjo>38.0</latprjo>

<feast>1968500.0</feast>

<fnorth>0.0</fnorth>

</lambertc>

</mapproj>

<planci>

<plance>row and column</plance>

<coordrep>

<absres>0.5</absres>

<ordres>0.5</ordres>

</coordrep>

<plandu>foot_us</plandu>

</planci>

</planar>

<geodetic>

<horizdn>D North American 1983 HARN</horizdn>

<ellips>GRS 1980</ellips>

<semiaxis>6378137.0</semiaxis>

<denflat>298.257222101</denflat>

</geodetic>

</horizsys>

Dimitri


7,433 post(s)
#03-Apr-24 05:15

The .zip file unzips into a .tif and a .tfw "world" file and .xml. The .tif is a perfectly good, accurate geotiff that imports just fine if you remove (or rename by adding a - character to the front of their names) the .tfw and .xml files.

It's a classic case of a perfectly good GeoTIFF being messed up by sidecar files that specify something incorrectly. See the "Projections from Accessory Files" section of the Projections topic in https://manifold.net/doc/mfd9/index.htm#projections.htm for how what's in sidecar files will override the projection info, if any, specified within the main file.

The imported image is shown below overlaid on a google satellite layer in 9:

Attachments:
good_import.png

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