<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Wayne -- <div>Without knowing what "asciigrid" is doing, it's hard to say what the problem might be. Have you tried to export the data as a geotiff and importing that into GRASS? Also, you should try to find an NDFD variable such as land mask that would have recognizable non-meteorological features in the data -- then you could reliably point to the data set that has the bad navigation, either in your GrADS descriptor or in your ascii output. </div><div>--Jennifer</div><div><br></div><div><br><div><div>On Oct 5, 2010, at 5:29 PM, Wayne Gibson wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div> In attempting to use the temperature National Digital Forecast Grids <br>(NDFD) with GRADS, I've found some unexpected results. If I export the <br>grids to ASCII format and read them into another GIS package (GRASS), <br>the temperature minimum at a location near Las Vegas are shifted in <br>space westward into California. The original NDFD grids are in Lambert <br>projection GRIB2 format.<br><br>My steps are<br><br>1) create GRADS control file using g2ctl.pl<br>2) Created index file using gribmap<br>3) Run Grads<br><br>open temperature.bin.ctl<br>define newgrid=tmpsfc-273.15<br>asciigrid newgrid output.asc<br><br>4) Import into GRASS, display and compare the geographic locations of <br>the temperature minima.<br><br>Here are 2 links for graphics showing the apparent shift between the <br>GRADS plot and the GRASS GIS plot.<br><br>GRADS original: <br><a href="http://prism.oregonstate.edu/~gibson/grads/grads_original.png">http://prism.oregonstate.edu/~gibson/grads/grads_original.png</a><br>GRASS shifted: http://prism.oregonstate.edu/~gibson/grads/grass_shifted.png<br><br>As you can see, the feature pointed to by the arrows in each plot has <br>significantly change location in space.... about 1 degree in longitude. <br>I've not reset the dimensions (set x, set y)<br><br>Perhaps this is an issue with the way that the National Weather Service <br>creates these grids. Wesley Ebisuzaki has confirmed that the NDFD <br>grids are encoded with an unusual scanning mode. wgrib2 will not work <br>with these grids and the "-new_grid" switch.<br><br>At this point in time, I'm not sure what other options I have. I've <br>been using this paradigm for years converting NWS Stage IV radar data in <br>GRIB1 format to ASCII grids successfully ... no apparent shift in the <br>data. I tried exporting the data using fprintf but had other problems <br>(sent a message to the user list a couple days ago). Somehow I need to <br>export the data to an ASCII grid format.<br><br>Wayne Gibson<br>Oregon State University<br><br>-------------------<br>ga-> q config<br>Config: v2.0.a8.oga.1 little-endian readline printim grib2 netcdf <br>hdf4-sds hdf5 opendap-grids,stn athena geotiff shapefile<br>Grid Analysis and Display System (GrADS) Version 2.0.a8.oga.1<br>Copyright (c) 1988-2010 by Brian Doty and the<br>Institute for Global Environment and Society (IGES)<br>This program is distributed WITHOUT ANY WARRANTY<br>See file COPYRIGHT for more information.<br><br>Built Mon Jul 12 21:25:55 EDT 2010 for i686-pc-linux-gnu<br><br>This version of GrADS has been configured with the following options:<br> o Built on a LITTLE ENDIAN machine<br> o Athena Widget GUI ENABLED<br> o Command line editing ENABLED<br> http://tiswww.case.edu/php/chet/readline/rltop.html<br> o printim command for image output ENABLED<br> http://www.zlib.net<br> http://www.libpng.org/pub/png/libpng.html<br> http://www.libgd.org/Main_Page<br> o GRIB2 interface ENABLED<br> http://www.ijg.org<br> http://www.ece.uvic.ca/~mdadams/jasper<br> http://www.nco.ncep.noaa.gov/pmb/codes/GRIB2<br> g2clib-1.1.8<br> o NetCDF interface ENABLED<br> http://www.unidata.ucar.edu/software/netcdf<br> netcdf 4.1.1 of Jul 12 2010 21:21:40 $<br> o OPeNDAP gridded data interface ENABLED<br> o OPeNDAP station data interface ENABLED<br> http://iges.org/grads/gadoc/supplibs.html<br> libgadap 2.0.oga.1<br> o HDF4 and HDF5 interfaces ENABLED<br> http://hdfgroup.org<br> HDF 4.2r5<br> HDF5 1.8.4<br> o GeoTIFF and KML output ENABLED<br> http://www.libtiff.org<br> http://geotiff.osgeo.org<br> o Shapefile interface ENABLED<br> http://shapelib.maptools.org<br><br>For additional information please consult http://iges.org/grads<br>--------------------------<br><br><br>_______________________________________________<br>gradsusr mailing list<br>gradsusr@gradsusr.org<br>http://gradsusr.org/mailman/listinfo/gradsusr<br></div></blockquote></div><br><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div>--</div><div>Jennifer M. Adams</div><div>IGES/COLA</div><div>4041 Powder Mill Road, Suite 302</div><div>Calverton, MD 20705</div><div><a href="mailto:jma@cola.iges.org">jma@cola.iges.org</a></div><div><br class="khtml-block-placeholder"></div><br class="Apple-interchange-newline"></span></span></div></span> </div><br></div></body></html>