[pdal] [gdal-dev] LiDAR data formats

[Howard Butler]

On Nov 19, 2012, at 2:37 AM, Chaitanya kumar CH <chaitanya.ch at gmail.com> wrote:

> Hi,
> 
> Can someone tell me the most common data formats useful for storing the LiDAR data including the LiDAR specific data.

LiDAR industry's GeoTIFF or Shapefile is the ASPRS LAS format, with all the good and bad connotations of each in terms of specification stewardship, variability of purported compliant output, and specification complexity. However, the specification has been quite successful at its stated purpose, which is to provide an interchange format for airborne LiDAR data. LAS is also sometimes used for terrestrial and mobile LiDAR, but it can be a somewhat poor fit in those situations.

LAZ, linked earlier, is an extension of LAS to provide a compressed variant of the format using arithmetic encoding. The software to read and write LAZ is provided as a LGPL C++ library, and its use within the industry is increasing due to the availability of the open source library and the rather bloated nature of LAS.  LAS and LAZ are very much linked in terms of what they provide as far as format capabilities, however.

There is also the ASTM E57 standard, with its open source implementation libe57, that provides an alternative to LAS that works with polar, terrestrial, and mobile data a little bit better than LAS. It does not have wide support within the industry thus far, and it's unclear as to whether it will ultimately get the uptake to push it over LAS in terms of volume archival data. 

Plain old freeform delimited text still overshadows the LiDAR industry, much like it did to the raster one a generation or two ago. In my opinion this is due to the fact that hardware vendors tend to only support the bare minimums within their export data (such as somewhat naked LAS), and the fact that the industry's specifications are not rich enough to effectively deal with LiDAR data such as full waveform characterization with all of the auxiliary information required to be usable. 

Howard
http://pointcloud.org