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Locate outliers in LiDAR Dataset

Question asked by rob_ford16 on Jul 5, 2016

This is a question that links back to this discussion:


Unfortunately, I never was able to get the locate outliers to work correctly....ESRI doesn't have any good examples on how this tool should be properly used. I am attempting to filter out any LiDAR points that have more than 100 foot difference from the surrounding points. I set my comparison filter in the Locate Outliers tool as such:



The output is not what I expect to see as I know where many outliers are but the tool is not flagging them.The following picture is a screenshot of the Minus tool output. The circled point says it is 1,782 feet tall. Obviously this is not correct. The locate outliers tool does not flag any points in my LAS dataset  near this point.


Now that I have my building footprints layer, I want to calculate the max z value / elevation for each polygon to get the building height using the Minus tool output. This outlier, if it were within a building footprint polygon, would then tell me my building is 1,782 feet tall!



Am I misunderstanding how the locate outliers tool should be used? Is there a way to just locate local outliers from the Minus tool output raster? The ultimate question is how do you throw out outliers and get the true max height per polygon?


I had thought about doing something with standard deviations (only consider points within a polygon that are within 2 standard deviations of the mean raster elevation value), but am unsure how to do this.


Thank you guys!