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HI Nikolas: So I dont see any such grib record in the file. I would expect discipline = 0, category = 3, parameter = 6 according to the Note. There is likely some formula we need to know also, using the level values (32-33, 33-34, etc). You might want to contact NCEP to see if you can track that down. I also see that I dont in fact deal with this case, although some of the mechanism for doing so is done(VExplicitField). So, Im sorry I cant help you. If you do locate the missing grib record and the correct formula, send it along and ill have a look at it. John On Wed, Dec 7, 2016 at 6:05 AM, Dahn, Nikolas < nikolas.dahn@xxxxxxxxxxxxxxxxxxxxxx> wrote: > Thank you kindly for your support. I have uploaded a file to the following > URL: > https://mega.nz/#!JkI0DIbJ!-P7VqflJJ2jnPDGA3BB158IthLEGojT756xPEF2wgeQ > > The following variables use the generalized height coordinates: > - Temperature > - Pressure > - u-component_of_wind > - v-component_of_wind > > Up till now I was not able to find the corresponding 3D-Grib-Message, but > I'm not sure how to look for it either. I am happy with my solution for > now, but I suspect there might be more data hidden somewhere (?). > > Thanks, > Nikolas > > PS: John, thanks for the hint at the 5.0 branch. I wasn't aware of it. I > will check it out in the near future. > > > ------------------------------ > *Von:* Antonio S. Cofiño [antonio.cofino@xxxxxxxxx] > *Gesendet:* Dienstag, 6. Dezember 2016 16:08 > *An:* John Caron; Dahn, Nikolas > *Betreff:* Re: [netcdf-java] Reading GRIB2 levels data > > Dahn, if you want I can provide you a sftp where you can put the file, > and make it available to everyone via HTTP. (or restricted what you > prefer). > > Just sent me your SSH public key > > Antonio > > > -- > Antonio S. Cofiño > Associate Professor and Researcher > Grupo de Meteorología de Santander > Dep. of Applied Mathematics and Computer Sciences > Universidad de Cantabria (Spain) > > Academic Visitor > National Centre for Atmospheric Science > Department of Meteorology > School of Mathematical, Physical and Computational Sciences > University of Reading (UK) > http://antonio.cofino.es > > On 06/12/16 14:33, John Caron wrote: > > Hi Nikolas: > > 1. The best version of the library to work on with GRIB is 5.0. > > https://www.unidata.ucar.edu/software/thredds/v5.0/netcdf- > java/documentation.html > > 2. Generalized Vertical Height Coordinate (see Note 4) > > The definition of a generalized vertical height coordinate implies the > absence of coordinate values in section 4 but the presence of an external > 3D-GRIB message that specifies the height of every model grid point in > meters (see Notes for section 4), i.e., this GRIB message will contain the > field with discipline = 0, category = 3, parameterm = 6 (Geometric height). > > So the code has to search though the file to look for another GRIB record > ("an external 3D-GRIB message") to find the coordinates. So the PDS does > not have the information. > > There are some heuristics somewhere to do this. Ill have to dig around for > where that is, but (assuming it finds it) it should create the correct > coordinate system at the GridDataset layer. > > > 3. To help you any further I will need a copy of the file. Can you put on > ftp or dropbox or something? > > Regards, > John > > On Mon, Dec 5, 2016 at 9:50 AM, Dahn, Nikolas <nikolas.dahn@iosb-ast. > fraunhofer.de> wrote: > >> I found a fix and a way to apply it as a temporary hack. Basically what >> happens is the following: >> - In Grib2CollectionBuilder.Grib2Rectilyser.make unique coordinate >> systems are built from the various PDS sections >> - The PDS' data sections are collected into VariableBags >> - To determine which coordinates are used the vertical height unit is >> examined, among others >> - This unit is (usually) provided by the Grib2Customizer (an >> implementation of GribTables) >> - The current implementation lacks a switch-case for code 150 >> (generalized vertical height) and the default mapping defines the unit as >> 'null' >> - From this it is determined that no vertical coordinate is present >> - Thus the coordinate is missing and the builder builds the coordinate >> system without the height coordinate >> - In the end most of the data is missing because the later data sections >> overwrite the earlier ones, as one of their distinguishing dimensions is >> missing >> >> The fix is quite simple: all I did was adding case statements for code >> 150 in Grib2Customizer.getVertUnit(int) and >> Grib2Customizer.getLevelNameShort(int). A patch is attached below. >> >> For those who stumble over this and don't have access to a patched >> version, you can derive a class from Grib2Customizer and override the two >> offending methods. Then set a private variable of Grib2Customizer via >> reflection like shown below. I recommend doing this in a static block. >> >> Field f = Grib2Customizer.class.getDeclaredField("wmoStandardTable"); >> f.setAccessible(true); >> f.set(null, MyGrib2Customizer.factory(0, -1, -1, -1, -1)); >> >> Cheers, >> ~ >> >> >> Patch: >> ==== >> --- ucar/nc2/grib/grib2/table/Grib2Customizer.java.orig 2016-12-05 >> 17:44:09.663099300 +0100 >> +++ ucar/nc2/grib/grib2/table/Grib2Customizer.java.patched 2016-12-05 >> 17:45:16.147099300 +0100 >> @@ -408,6 +408,9 @@ >> case 119: >> return new GribLevelType(code, "Pa", null, false); // ?? >> >> + case 150: >> + return new GribLevelType(code, "numeric", null, true); >> + >> case 160: >> return new GribLevelType(code, "m", "sea level", false); >> >> @@ -505,6 +508,8 @@ >> return "hybrid_pressure"; >> case 120: >> return "pressure_thickness"; >> + case 150: >> + return "generalized_vertical_height"; >> case 160: >> return "depth_below_sea"; >> case GribNumbers.UNDEFINED: >> >> _______________________________________________ >> NOTE: All exchanges posted to Unidata maintained email lists are >> recorded in the Unidata inquiry tracking system and made publicly >> available through the web. Users who post to any of the lists we >> maintain are reminded to remove any personal information that they >> do not want to be made public. >> >> >> netcdf-java mailing list >> netcdf-java@xxxxxxxxxxxxxxxx >> For list information or to unsubscribe, visit: >> <http://www.unidata.ucar.edu/mailing_lists/>http://www.unidata.ucar.edu/ >> mailing_lists/ >> > > > > _______________________________________________ > NOTE: All exchanges posted to Unidata maintained email lists are > recorded in the Unidata inquiry tracking system and made publicly > available through the web. Users who post to any of the lists we > maintain are reminded to remove any personal information that they > do not want to be made public. > > > netcdf-java mailing listnetcdf-java@xxxxxxxxxxxxxxxx > For list information or to unsubscribe, visit: > http://www.unidata.ucar.edu/mailing_lists/ > > >
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