+gdal-dev Some hackish test code I had laying around from last year...
https://gist.github.com/schwehr/01f6604afc7757ea0a676f0eb28be582 You might also be able to just write 80 layers of u-v, pick out pairs for each depth layer and have the rendering system do the conversion(s). You could use whatever you want once you have a geotiff. In this screenshot, I made an 80-layer geotiff of u and v alternating layers and uploaded that to Earth Engine. It's been a long time since I heavily used mapserver, but you could probably do the same there. https://www.flickr.com/photos/schwehr/26895009754/ On Mon, Jun 6, 2016 at 7:51 AM, Stephen Woodbridge <wood...@swoodbridge.com> wrote: > On 6/5/2016 2:04 PM, Kurt Schwehr wrote: > >> Stephen, >> >> Take a look at these two discussions for starters on working with hycom: >> >> >> http://gis.stackexchange.com/questions/167155/how-can-i-make-geotiffs-of-individual-depth-layers-in-the-hycom-ocean-circulatio >> > > Hi Kurt, > > In the link above you mention: > > I've got some code written the does things like calculate the speed >> inm/s from the UV and creates a geotiff, etc >> > > Can you share this code, it sounds like exactly what I need for the > current vectors? And I'm interested in figuring out how to read/write and > work with the netcdf files. > > I think for now I'll work with the "u" datasets as they seem that they > will be much easier place to start. > > Thanks, > -Steve > > > >> http://gis.stackexchange.com/questions/170882/how-can-a-make-a-netcdf-with-subgroups-smaller >> >> You should start with the regular grids. e.g. >> >> >> ftp://ftp.hycom.org/datasets/GLBu0.08/expt_91.1/data/hindcasts/2015/hycom_glb_911_2015093000_t000_uv3z.nc >> >> Make an 80 layer geotiff from the u/v and then use mapserver as Even >> suggested. >> >> -kurt >> >> >> On Sat, Jun 4, 2016 at 6:29 AM, Even Rouault <even.roua...@spatialys.com >> <mailto:even.roua...@spatialys.com>> wrote: >> >> Hi, >> > >> > I want to convert some HYCOM data into GTiff format and I'm a little >> > lost on how to get started, whether I can do what I need just using >> a >> > vrt or if I'm going to have to write code to process the data. >> > >> > To start with I have placed gdalinfo on one file here: >> > http://imaptools.com:8080/dl/hycom-gdalinfo.txt >> > >> > The data comes from http://hycom.org/dataserver/glb-analysis >> > and I will need to be using GLBa0.08 dataset. >> > >> > I have two use cases: >> > >> > 1) The simple one is to extract say Band 1 into a georeferenced >> GTiff >> > and apply color to using color ranges without loosing the NODATA. I >> > think I can do later using .vrt, correct? >> >> gdaldem color-relief can output to a VRT, but given that this netCDF >> file is >> georeferenced through a geolocation array, you'll likely have first >> to run >> gdalwarp -geoloc to have something useful at the end. >> >> > >> > I'm not sure how to deal with the georeferencing, because the >> download >> > site says: "Native hycom .[ab] data converted to NetCDF on native >> > Mercator-curvilinear HYCOM horizontal grid" but that does not seem >> in >> > sync with the Metadata in the file. >> > >> > 2) The more complicated case is that there are two files: >> > a) eastward_sea_water_velocity (aka: u, u-velocity) >> > b) northward_sea_water_velocity (aka: v, v-velocity) >> > that I would like to use to create a grid of vectors with arrowheads >> > using u and v to define the vector and where the color of the >> vector is >> > related to the magnitude of its length. Ultimately this data will >> get >> > rendered via mapserver so I'm wondering if I can do this via a >> GTiff or >> > if I will have to resort to creating a massive point shapefile with >> > attributes of angle and magnitude and use a symbol. It seems like it >> > would be best if I can keep the data as a GTiff and then sample the >> > points and render the vectors on the fly for when you zoom in/out. >> >> See >> http://mapserver.org/input/vector/vector_field.html >> >> You don't need to create a vector file. >> >> You'll have to preprocess your file to get the u and v bands in the >> same >> raster. >> >> Even >> >> -- >> Spatialys - Geospatial professional services >> http://www.spatialys.com >> _______________________________________________ >> gdal-dev mailing list >> gdal-dev@lists.osgeo.org <mailto:gdal-dev@lists.osgeo.org> >> http://lists.osgeo.org/mailman/listinfo/gdal-dev >> >> >> >> >> -- >> -- >> http://schwehr.org >> > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > -- -- http://schwehr.org
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