using Mapserver for on-the-fly raster data?

[Jeff de La Beaujardiere]

Frank Warmerdam wrote:
> Note that there is a builtin limit on the number of layers.  You may
> need to recompile with a higher limit if you will end up serving a
> very large number of layers. 

Already recompiled with layer limit 10000!

> As of 4.6 (actually it might have been in 4.4 too), MapServer supports
> the ability to apply classification to non-8bit raster data.  This is discussed
> in the raster howto at:
> 
>    http://ms.gis.umn.edu/docs/howto/raster_data

Thank you--I had ignored and forgotten that section of the Raster Howto, 
but I see that it may be just the ticket here. My other dataset is 
satellite imagery that I serve as-is [By the way, the performance of the 
GeoTIFFs with overviews built using GDAL is *phenomenal* compared to 
serving the PNGs that I get from my source.]

> Well, then you need to implement the full WMS support.  I was just 
> suggesting that your preprocessor would find the LAYERS info,
> and use it to pull the required dataset out of the "big file" before 
> processing the request.  This leaves MapServer doing all the 
> subsetting, classification etc.

Given what you just told me about raster classification, this is indeed 
a possibility.

> However, if you were to start from the python WMS that Allan wrote
> for his WMS cookbook you might well be able to implement a small
> custom WMS service calling out to IDL to do some of the work.  

Actually, I already have my own custom WMS using Perl + IDL that we used 
for the GLOBE Program (www.globe.gov), but it would require so dusting 
off and retooling. I definitely would prefer to use Mapserver if possible.

Many thanks,
Jeff DLB