=== Q: How do I convert between LAS and ASCII file formats? ===

To convert between LAS and ASCII point cloud formats use the free `las2txt` and `txt2las` tools available as part of LAStools. These are available to download from: https://github.com/LAStools/LAStools (note: download also contains paid for tools not required for conversion). Binaries are provided for Windows. For Linux and OS X you need to compile using the included 'Makefile'

==== LAS to ASCII ====

To export as 9 column ASCII files, as delivered by NERC-ARF between 2011 and 2015 use the following command:

{{{
las2txt -parse txyzicrna -sep space -i in_las.las -o out_ascii.txt
}}}

If you need to export in the 8 column format used by NERC-ARF between 2009 and 2010 use the following command instead:

{{{
las2txt -parse txyzicrna -sep space -i in_las.las -o out_ascii.txt
}}}

For more details on available options see the [https://github.com/LAStools/LAStools/blob/master/bin/las2txt_README.txt las2txt README]

==== ASCII to LAS ====

To convert the 9 column ASCII files as delivered by NERC-ARF between 2011 and 2015 to LAS format use the following command:

{{{
txt2las -iparse txyzicrna -i in_ascii.txt -o out_las.las
}}}

To convert the 8 column format used by ARSF between 2009 and 2010 use the following command instead:

{{{
txt2las -iparse txyzicra -i in_ascii.txt -o out_las.las
}}}

To reduce the file size you can change the extension of the output file to '.laz' to save as LASzip files. These can be read by a number of packages and easily converted back to uncompressed LAS files using [https://github.com/LAStools/LAStools/blob/master/bin/laszip_README.txt laszip].

==== Converting on the JASMIN platform ====

If you are accessing NERC-ARF data archived at [http://neodc.nerc.ac.uk/ NEODC] and have an account on [http://jasmin.ac.uk/ JASMIN] LAStools are installed and can be loaded using:

{{{
module load contrib/arsf/lastools
}}}

If you have access to the ARSF archive it will be mapped as `/neodc/arsf` allowing you to convert ASCII files to LAZ before downloading.

==== Gridded ASCII format ====

If you need to save as a gridded ASCII format (.asc) rather than a point cloud you can use the [https://github.com/pmlrsg/arsf_dem_scripts ARSF DEM Scripts] to export as ENVI format and then convert to ASCII using [http://www.gdal.org/gdal_translate.html gdal_translate]. For example:

{{{
las_to_dsm.py in_las.las -o out_raster.dem

gdal_translate -of AAIGrid out_raster.dem out_raster.asc
}}} 

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