Surface Precision tool in LP360

The Surface Precision tool for LP360 is designed to provide a robust and automated assessment of the precision (or noise) on smooth surfaces within lidar data point clouds. It’s grounded on the ASPRS definition of surface precision as a measure of a lidar system’s ability to detect hard, flat surfaces, which in practical terms refers to the “fuzziness” or noise in the point cloud. This tool evaluates point cloud data to ensure precision is within specifications, serving as an indicator of the ranging precision and sensor stability. 

The BIT (Business Intelligence) Add-On license product or the LP360 Geospatial license is required to use this tool.

This tool is very useful for identifying locations along your LAS data that may not be aligned well or that may have noise that could impact the quality of your final products. Ideally, this tool is used to analyze the "noise envelope" or thickness of the point cloud. See an example of a "noise envelope" in the cross section of a flat area below.

Before deciding on the parameters to run, ensure the desired input points are selected in the Input Points Filter. The Input Point Filter dialog works the same as the Live View Filter and allows you to filter specific points for processing. The default will have all points selected.

After setting the Input Points Filter, you have 3 options for Map Selection for how to estimate precision of your LAS surface.

• Global will be executed over the entire LAS layer. This option can be used for misalignment analysis or noise envelope analysis.
  • Use this option after geocoding to check how well multiple flight lines align with each other OR after performing strip adjustment to see how well distributed the noise is across each flight.
• Interswath analyzes the noise envelope in overlap areas between flight lines.
• Intraswath analyzes the noise envelope of each swath individually (by each flight line)