LAS data not displaying

Question

Hello, I am relatively new at ArcGIS and I need to view lidar data that I have in .las format.  I have those files and a shape file, the data is separated into tiles.  I created a LAS dataset but when I open it in ArcMap all that displays is a grid of boxes, which is the tiles_index layer, the other layer is selected as well, the LAS dataset layer, and it has elevation values listed under it.  No data points are displayed, and it reads "Data percentage: 0."  I can not figure out how to get the data to display.

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JustinJohnston · Answer

I ran that CheckLAS when all of my points dissapeared when trying to classify points.  I get the following in the log file when scanning points.  Any ideas on how to resolve this problem?  Is there a way to "unclassify" points?  Apparently that tool messed up the records and broke my LAS file.

WARNING 1: Sum of point counts by-return (0) not equal to point-record count (12263419)
WARNING 2: 12263419 points have return-number 0
WARNING 3: 5 points have outside bound coordinates
Header: xMin = -8552418.564819336, yMin = 4900389.729583740, zMin = 458.543075562
Points: xMin = -8552418.565000000, yMin = 4900530.134000000, zMin = 458.543000000

Header: xMax = -8552091.118438721, yMax = 4900701.589935303, zMax = 530.973915100
Points: xMax = -8552091.118000001, yMax = 4900701.590000000, zMax = 530.974000000

JanWilkening · Answer

There are is a collection of useful tools you might want to check out:

http://www.cs.unc.edu/~isenburg/lastools/

We had a customer with a similiar problem (it turned out that his coordinates were inappropriate), the las2shp.exe and las2las.exe helped solving the problem.

Furthermore, there is a free CheckLAS Executable on ArcGIS Online: http://www.arcgis.com/home/item.html?id=e49eaa594fb04f7f8827915345a255aa‌

Hope that helps!

IanMurray · Answer

First off, make sure you turn off the index grid, or move it beneath your lidar points.  Currently it is covering them even if they were displaying.

LIDAR data is limited in display in ArcGIS to about 5 million points, and if too many are in the visible extent they will not display in some cases.  I'd right click LIDAR dataset and set the point display tab to 5 million(the max), I believe the default is 800,000.  Depending on how large your dataset is, you will need to zoom in futher to your map for the points to display.