[gis_info] ArcGIS - NAD83 HARN and NAD83(2011) data shift bug

[CALLAHAN Brady * OPRD]

For those of you not interested in the difference between the NAD83 HARN and NAD83(2011) and a related issue with ArcGIS software there is no need to read further.

We ran across a bug in ArcGIS 10.2.2 about a week ago related to these two datums where the ArcMap display will produce a data shift to the east and south of 44 and 25 inches respectively. The shift showed up when viewing a Mosaic Dataset that was defined with a NAD83 HARN datum but viewed in a NAD83(2011) data frame. The datum transformation in ArcGIS available to convert between these two datums is zero based, meaning its parameters are all zero, so no transform actually takes place. Therefore the result between using a transformation setting of 'None' or using the available transformation should be the same. The bug is that the software shifts the data on the fly when it shouldn't.

ESRI has logged this as NIM104810 with a Severity of High:  [The offset  between data on NAD 1983 HARN Oregon Statewide Lambert (intl feet) and NAD 1983 (2011) Oregon Statewide Lambert (Intl Feet) is approximately 12 inches but offset displays as about 50 inches in ArcMap with raster data]

The issue we discovered was observed in both Oregon Statewide Lambert and Oregon State Plane but we didn't do any testing with other coordinate systems.

This was a big deal for us since we still have lots of raster data (ortho, lidar) that is defined using NAD83(HARN) since no appropriate coordinate system definition, i.e. NAD83(CORS96), was available through ArcGIS at the time of acquisition. We're working to get this remedied internally but other folks may want to consider the ramifications to their own workflows.

For anyone interested the NGS has released the GEOCON and GEOCON11 tools that provide a transformation between NAD83 HARN - NAD83 (NSRS2007) and then NAD83 (NSRS2007) - NAD83 (2011).  You can find the announcement here: http://www.ngs.noaa.gov/web/news/NGS_Announces_Joint_Release_of_GEOCON.shtml



Brady Callahan, GISP
GIS Program Leader
Oregon Parks & Recreation

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