[mapserver-users] Elevation data from DEM/LIDAR?

[Johan Forsman]

Hello All:

I have an idea to improve our mapserver instance, and I come to you asking for help formulating an approach to realizing it.

What I want is retrieve elevation data from DEM/LIDAR. I have attempted keyword searches for various combination of MapServer+DEM+LIDAR without much success.

I am using MapServer 5.4.2 from the MS4W package.

I have access to elevation data in the form of USGS DEM rasters, either from 1:24000 quads or from a much denser (and far larger) LIDAR dataset. 

The quad DEM dataset consists of just under 1000 quads stored as individual .dem files, in what appears to be 16-bit signed integer format, each file with a unique name equal to the USGS quad code. Files appear to be 1-2 megs in size on disk.

The LIDAR dataset appears to use a 32-bit float format, there are over 3500 quarter-quads stored as individual .dem files with unique names that do not correspond directly to the USGS quarter-quad code (but I can possibly generate a lookup table for the translation). Alternatively the LIDAR data is available as CSV format. Files are quite large, 10-12 megs for the rasters and 150 megs for the CSVs. Each.

I am not (yet) interested in displaying the data as an image, only returning the point values at any given location on the displayed map. We are using Geomoose2 for our front-end, but I'll work on the display of the data once I determine how best to "generate" it. There are no services (e.g. WMS) published by our MapServer instance.

How should I (can I? do I need to?) approach crafting a mapserver file that points to 3500+ individual rasters?

Am I thinking all wrong about this? This is very likely.

Should I just forget about the whole thing? Can it even be done in a reasonable way?

Please opine at will on this subject.

Thanks!
/Johan.

----------------------
Johan Forsman
Geologist
Safe Drinking Water Program
Louisiana Department of Health and Hospitals
Office of Public Health
Telephone: 225.342.7309
Telefax: 225.342.7303