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One way to proceed using SAGA GIS, but I'm sure other programs may do this also: open your points and grid: convert you points to gridcells (module shape to grid), in the same grid system as your ot …

If speed is an issue, consider using RSAGA with the profiles from lines module. http://www.saga-gis.org/saga_tool_doc/7.2.0/ta_profiles_4.html

I would stick to R. If speed is really a problem ( I doubt so 90.000 is not such a big number) you could try finding relationships between a subset of your data. Actually the first thing I would do is …

Try http://www.zygrib.org/. As an alternative, saga gis also supports reading grib files so you can use that to convert to other file formats.

I'm not aware of any solutions that render on the client, but you may be interested in geotrellis, which could handle a lot of the required functionality on the server.

And you can always convert your raster to a point shapefile or point cloud. Operations on such a files may still be faster in SAGA GIS than they are on a raster in ArcGIS. …

You might know Lanczos filters or similar type of filters from your image programs, where they are often called 'sharpening filters'. A good example from this forumtopic: The first image shows the or …

Since you are using aerial images: do you need orthorectification? In that case I guess ILWIS would be your best bet, although GRASS also supports it (I haven't tried that myself though). Work flow f …

As far as I understand your question, you might be very interested in the techniques mentioned in this paper: Gallant, J.C., Dowling, T.I. (2003): 'A multiresolution index of valley bottom flatness fo …

workaround: values(onWindows)[values(onWindows)>128*256]<-values(onWindows)[values(onWindows)>128*256]-256*256 values(onWindows)[values(onWindows)==-9999]<-NA To dig deeper: It seems that raster calls …

You can use gdaltindex for this: http://www.gdal.org/gdaltindex.html It will however still create rectangles (eg 4+1 points) in the same reference system as the images. But I wonder whether that real …

EDIT: (Jan 13) I'm still seeking information on exactly how best to store a 3 dimensional 16-bit integer BIP raster and be able to efficiently query a single z-axis "column" of data. … Querying such a raster should not really pose large problems. You can read binary data directly using all program languages, and access is fast. …

This is not possible using GDAL. You could use other free tools however, eg saga gis: saga_cmd shapes_grid "Grid Values to Shapes" -GRIDS=grid.sgrd -POLYGONS=in.shp -SHAPES=out.shp-NODATA -TYPE=1

You may want to look at mb-system, which is specically made for mapping sea floors (I have no experience, I just know it exists): http://live.osgeo.org/en/overview/mb-system_overview.html Anyway, yo …