The IDL DataPoint has an article about native OPeNDAP support in IDL 8.2. This allows the use of IDL’s netCDF API to access remote data served via the DAP protocol (this is new for the Mac on 8.2, already present in Linux, and still not working on Windows as I mentioned in my review of IDL 8.2).

Mark shows an example of how to access some AIRS data at The HDF Group’s OPeNDAP-enabled server. I have some netCDF bindings that will work for remote data as long as the underlying library is capable; the seven NCDF_OPEN, NCDF_VARID, and NCDF_VARGET commands in the example can be replaced with:

IDL> topo = tx_nc_getdata(url, 'TopographyU274')
IDL> latitude = tx_nc_getdata(url, 'LatitudeU271')
IDL> longitude = tx_nc_getdata(url, 'LongitudeU272')

Contact me if you are interested.