I submitted a ticket regarding this issue:https://trac.osgeo.org/gdal/ticket/6051
Thanks Andre for your help on gis.stackexchange and here. Cheers, Markus Mueller ---- On Sun, 26 Jul 2015 09:34:58 -0700 Andre Joost <[email protected]> wrote ---- Can this VRT approach be used for MODIS sea ice data too? http://gis.stackexchange.com/questions/112547/reprojecting-modis-ice-sea-temperature-products-with-gdalwarp http://gis.stackexchange.com/questions/155326/reprojecting-modis-sea-ice-extent-and-ist-data-using-gdal note that especially older versions (before 2011) only produce garbage images with GDAL. Greetings, André Joost Am 25.07.2015 um 00:56 schrieb Michael Sumner: > Hello, I've put together an example of using NSDIC sea ice concentration > data with GDAL VRT. > > In this Github readme I list two example data sets, one for the Northern > and one for the Southern hemisphere where the raw > binary NSDIC .bin files have accompanying VRT files: > > https://github.com/mdsumner/NSIDC-seaice > > I'd really like to see this format as a GDAL driver, but I don't have the > C++ expertise to make it happen. I can offer help and testing if anyone was > interested in writing the driver, but I would also appreciate any guidance > and kick start for me to learn to do it myself. > > The format itself is detailed here, and everything required can be gleaned > from the header - though in the VRT pathway I simply skip the header and > apply the right CRS, orientation, grid size and geotransform: > > http://nsidc.org/data/docs/daac/nsidc0051_gsfc_seaice.gd.html#format > > The repo includes the minimal .vrt required to read this as a valid GDAL > data set and uses plotting in R with standard R > mapping tools to show that the interpretation is right, at least visibly. > > I have these questions: > > * what is the best template driver for these data, should it derive from > GDALPamDataset like JDEM or from RawDataset as ERS does? (I'm way out of > my depth here) > * is it appropriate to use this SRS when the datum is unspecified? I'm not > clear on the pitfalls here and how to advise downstream use > > I am competent with building GDAL but I get lost in the steps required to > add a new driver. A dummy example, or some more detailed guidance for how I > would apply the "GDAL Driver Implementation Tutorial" to these data would > be enough for me to flesh out the details. > > The projection SRS used are EPSG 3411 (north) and 3412 (south) as listed > here: > http://spatialreference.org/ref/epsg/3411/ > http://spatialreference.org/ref/epsg/3412/ > > I have otherwise written this support directly into the R package raster, > the R source for these files is here in this read-only mirror (raster is on > r-forge): > > https://github.com/cran/raster/blob/master/R/nsidcICE.R > > This works very well for R, but I'd prefer to see this format in GDAL so > that other languages have the same facility. There are other sea ice > concentration data sources, usually in HDF4 format - and they only need the > geotransform and SRS assigned for use in GDAL - so they need work as well > but not as fundamental as this raw binary format. This data source is very > extensive, with daily data at 25km resolution every day since 1979 with > only ~30 days total missing, and only a handful with problems in the map > coverage. > > Thank you. > > Cheers, Mike. > > > > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev > _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
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