GRASS files






Some documentation can be found on my page at Otago:

o  Scripts and examples of custom raster color map creation.

Tips for building GRASS on Debian GNU/Linux

o  Copy of NNBathy 1.80 interpolation software for

o  Some NVIZ examples:

The module will load and bin ungridded x,y,z ASCII data into a new raster map. The user may choose from a variety of statistical methods in creating the new raster. is designed for processing massive point cloud datasets, for example raw LIDAR or multibeam sonar swath data. It should work with a dataset of any size; currently the largest known success is a 379GB file (ran overnight to process 14.5 billion data points).

Detailed information is available on the help page.



  The GUI control window.

        [click on images to enlarge]


Here are some shots of the Jockey's Ridge, NC, LIDAR dataset after post-processing.
Roads, houses, ocean waves parallel to the beach, and highway lightpoles are clearly visible.
Google blurs the images a little (even the .png files) - the originals are infact substantially clearer -
you can even see traffic lights and cars. Compare with the Google Maps satellite view.



     "n" map containing scans per cell.


    "min" map interpolated into a surface using
    regularized splines (via and



     NVIZ representation of above xyz.min.rst map.



Sidescan and multibeam sonar folks might also be interested in:

  • The v.swathwidith module by David Finlayson for planning surveys. (development page)
  • An example of post-processing scanned paper sidescan swaths using thin plate spline warping with GDAL's "gdalwarp -tps" function. (debugging page)
  • MBSystem open source software from MBARI and Columbia Univ's Lamont-Doherty EO for the processing and display of swath sonar data.

LIDAR folks might also be interested in:

  • r.terraflow - computation of flow direction, flow accumulation and other basic topographic terrain indices from massive raster digital elevation models (DEM). From the Duke University STREAM project.
  • Flood simulation using r.lake. Includes fancy NVIZ visualization of Trento, Italy, by Markus Neteler.