Why is it important to determine the units of measurement in a LAZ file with inconsistent metadata for ArcGIS Pro?

Answer

A LAZ file is a compressed version of the LAS file format for light detection and ranging (lidar) and can be converted into LAS for viewing and examining, which requires choosing the right projections and units during conversion in ArcGIS Pro. Incorrect conversions may occur when working with LAZ files with inconsistent metadata, particularly from sources such as the United States Geological Survey (USGS). This could lead to the LAS data being displayed inaccurately on the map based on the true location.

As per USGS, consistent units of measurement for both horizontal and vertical units in meters are preferred. Mixed units (such as meters for horizontal units and feet for vertical units) are considered to vary from the specification and are noted as such in the spatial metadata. Appropriate metadata in a LAZ file ensures lidar data accuracy, depicting real-world features and data interoperability, facilitating seamless integration with additional geospatial datasets.

LAZ files cannot be opened and inspected in ArcGIS Pro, only converted into LAS. However, text editors such as Notepad++ can be used instead to read the metadata of a LAZ file. Once opened, the units of measure can be identified using the text editor search function. Searching for keywords such as ‘meters’, ‘metres’ or ‘feet’ results in a match indicating the units corresponding to the particular LAZ file.