[Gdal-dev] How to best perform raster cell aggregation

Emilio Mayorga emiliomayorga at gmail.com
Tue Feb 13 11:23:04 EST 2007

> I'm working with raster files, starting in the NetCDF format, but then
> moving them to .tif and .png based on how the user will need to manipulate
> them. One seemingly simple thing that I've been unable to find a simple
> solution for is resampling the data with an aggregation algorithm. For
> instance, I'd like to go from a 10 meter cell size to a 100 meter cell size
> where the value for a 100m cell is the sum of all the 10m cells that the
> 100m cell now represents. I have a very sparsely populated dataset, so
> averaging on resample tends to just push everything towards zero. What I'm
> looking for is the ability to see where very small data points exist when
> zoomed out.


You may want to look into NCO, the netcdf operator utility
(http://nco.sourceforge.net/). It's a  command-line swiss army knife
for performing operations on netcdf, including statistics across
dimensions, and may include aggregation/rebinning. If it does take
care of that step, you could first use an nco utility to perform the
aggregation, then gdal to convert to tif/png.

I haven't used nco in a long time, so I can't help much at all. Good luck.

-Emilio Mayorga
Post-Doctoral Researcher
Rutgers, The State University of New Jersey
Institute of Marine and Coastal Sciences
71 Dudley Rd.
New Brunswick, NJ 08901-8521, USA

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