LiDAR showing up east of actual location

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02-02-2016 12:06 PM
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New Contributor II

I downloaded a bit of LiDAR. I created a LAS dataset in ArcMap 10.3 and it's projecting about 500km east of my target location. The coordinate system is supposedly incorporated into the data (NAD_1983_2011_StatePlane_Florida_East_FIPS_0901, in m), so is it just intrinsically incorrect or am I doing something incorrectly? I tried a ton of different projections and can't get it right. Any advice would be appreciated!

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MVP Frequent Contributor

Some thoughts:

  • I'd suggest checking the coordinate system of the LidAR by using ArcCatalog and see if it matches the same values that are in the State Plane coordinate system that it is expected to be in.
  • What are you checking the LidAR against?  Are you absolutely certain that the layer you are checking it against is correctly located?
  • 500Km sounds like it is larger than a simple Datum shift (like NAD27 to NAD83).  Any chance a False Easting got assigned?

Chris Donohue, GISP

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New Contributor II

It looks like a false easting was assigned:

PROJCS["NAD_1983_HARN_StatePlane_Florida_East_FIPS_0901_Feet",GEOGCS["GCS_North_American_1983_HARN",DATUM["D_North_American_1983_HARN",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",656166.6666666665],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-81.0],PARAMETER["Scale_Factor",0.9999411764705882],PARAMETER["Latitude_Of_Origin",24.33333333333333],UNIT["Foot_US",0.3048006096012192],AUTHORITY["EPSG",2881]]</

How can I correct for this? Thank you for your help!

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MVP Notable Contributor

Where are you getting that projection string? Is it from the projection file (.prj)? And are you viewing this string in notepad or something similar? If so, you can just change that false easting to a 0.0 and save it again as the .prj file.

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New Contributor II

This is from a .xml file. I converted the las dataset to a raster and tried to Shift it over by the false easting but it's a little too far north now.

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Esri Notable Contributor

The difference between the false easting in your listed CRS that's using US survey feet, and the meter version of the zone is 456 km. Could the LIDAR have the wrong coordinate system defined?

Does it look like it could be sized wrong as well as offset?

Melita

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New Contributor II

I feel like it should be reliable as it's from USGS EarthExplorer, although I have never used LiDAR from there before.

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MVP Esteemed Contributor

could you provide a link since some of the data on that site doesn't have georeferencing applied

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New Contributor II

Fixed! Wrong CS it was as well. Thanks for your help!

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New Contributor III

Brittany, I'm having the same problem with the same LiDAR files.  Which CS did you find ultimately worked?  My Key West dataset is locating itself about halfway between Homestead and the Bahamas. 

305-809-3810

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