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LAS header coord sys GeoKeys incorrectly read by ArcGIS?

Question asked by CALLAHB on Mar 9, 2015
Latest reply on Jun 15, 2015 by jbrod

We just ran into an issue trying to get ArcGIS LAS Datasets and Mosaic Datasets to correctly interpret the coordinate reference system in a LAS 1.2 file header. The LAS 1.2 spec uses the GeoTIFF GeoKey tags as opposed to the newer 1.4 spec which uses the WKT. Does anyone know which GeoTIFF GeoKeys translate to form the Geographic Coordinate System (GCS) portion of an ESRI defined coordinate system?

 

We tried to define a GCS_North_American_1983 using:

 

key 2050 - GeogGeodeticDatumGeoKey: Datum_North_American_Datum_1983 

key 2056 - GeogEllipsoidGeoKey: Ellipse_GRS_1980

 

but for ArcGIS this resulted in:

 

Datum: D_North_American_1983

Spheroid: GRS_1980

Semimajor Axis: 6378137.0

Semiminor Axis: 6378137.0

Inverse Flattening: 0

I'm wondering if perhaps instead we should be using:

 

key 2048 - GeographicTypeGeoKey: GCS_NAD83

key 2056 - GeogEllipsoidGeoKey: Ellipse_GRS_1980

 

Does anyone know this spec and how to have it correctly interpreted?

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