<div dir="ltr">I figured it out after two weeks.<div><br></div>[user@asdf rtma]$ gdallocationinfo TMP_2M_0.tif 50 50<br>Report:<br> Location: (50P,50L)<br> Band 1:<br> Value: -999000000<div><br></div><div>The NoData value was undeclared in the Metadata. A quick run through 'gdalwarp' with the '-srcnodata "-999000000"' flag fixed this.</div>
</div><div class="gmail_extra"><br><br><div class="gmail_quote">On Sun, Apr 6, 2014 at 3:24 PM, Ryan Hickman <span dir="ltr"><<a href="mailto:ryan@allisonhouse.com" target="_blank">ryan@allisonhouse.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">I'm having a rather unique problem with displaying GeoTiffs using Mapserver. When I generate my GeoTiffs using GrADS, I get solid colored tiles when zoomed out.<div>
<br></div><div><a href="http://d.pr/i/p57n" target="_blank">http://d.pr/i/p57n</a><br>
</div><div><br></div><div>Higher zoom levels look just fine, for the most part. Unless I pan to the Southern-fringe.</div><div><br></div><div>Yet when using GDAL to generate my GeoTiff, everything looks fine.</div><div><br>
</div><div><a href="http://d.pr/i/m9l1" target="_blank">http://d.pr/i/m9l1</a><br></div><div><br></div><div>The mapfiles are exactly the same (except EXTENT, SIZE.) I am obviously using COLORRANGE for my colors.</div><div>
<br></div><div>
GDALInfo for GrADS GeoTiff:</div><div>
Driver: GTiff/GeoTIFF<br>Files: TMP_2M_0.tif.save<br>Size is 4270, 2601</div><div><br></div><div>Coordinate System is:<br>GEOGCS["WGS 84",<br> DATUM["WGS_1984",<br> SPHEROID["WGS 84",6378137,298.257223563,<br>
AUTHORITY["EPSG","7030"]],<br> AUTHORITY["EPSG","6326"]],<br> PRIMEM["Greenwich",0],<br> UNIT["degree",0.0174532925199433],<br> AUTHORITY["EPSG","4326"]]<br>
Origin = (-150.017168744489595,80.029519859090939)<br>Pixel Size = (0.024600100981457,-0.023088209090909)<br>Metadata:<br> TIFFTAG_SOFTWARE=GrADS version 2.1.a1 <br> TIFFTAG_XRESOLUTION=0.0025761127<br> TIFFTAG_YRESOLUTION=0.0032679737<br>
TIFFTAG_RESOLUTIONUNIT=2 (pixels/inch)<br> AREA_OR_POINT=Area<br>Image Structure Metadata:<br> INTERLEAVE=BAND<br>Corner Coordinates:<br>Upper Left (-150.0171687, 80.0295199) (150d 1' 1.81"W, 80d 1'46.27"N)<br>
Lower Left (-150.0171687, 19.9770880) (150d 1' 1.81"W, 19d58'37.52"N)<br>Upper Right ( -44.9747376, 80.0295199) ( 44d58'29.06"W, 80d 1'46.27"N)<br>Lower Right ( -44.9747376, 19.9770880) ( 44d58'29.06"W, 19d58'37.52"N)<br>
Center ( -97.4959531, 50.0033039) ( 97d29'45.43"W, 50d 0'11.89"N)<br>Band 1 Block=4270x1 Type=Float64, ColorInterp=Gray</div><div><br></div><div>GDALInfo for GDAL-produced GeoTiff:<br></div>Driver: GTiff/GeoTIFF<br>
Files: TMP_2M_0.tif.orig<br>Size is 2606, 1228<br><br>Coordinate System is:<br>GEOGCS["WGS 84",<br> DATUM["WGS_1984",<br> SPHEROID["WGS 84",6378137,298.257223563,<br> AUTHORITY["EPSG","7030"]],<br>
AUTHORITY["EPSG","6326"]],<br> PRIMEM["Greenwich",0],<br> UNIT["degree",0.0174532925199433],<br> AUTHORITY["EPSG","4326"]]<br>Origin = (-130.103386906477482,52.806959593909397)<br>
Pixel Size = (0.026575739741210,-0.026575739741210)<br>Metadata:<br> AREA_OR_POINT=Area<br>Image Structure Metadata:<br> INTERLEAVE=BAND<br>Corner Coordinates:<br>Upper Left (-130.1033869, 52.8069596) (130d 6'12.19"W, 52d48'25.05"N)<br>
Lower Left (-130.1033869, 20.1719512) (130d 6'12.19"W, 20d10'19.02"N)<br>Upper Right ( -60.8470091, 52.8069596) ( 60d50'49.23"W, 52d48'25.05"N)<br>Lower Right ( -60.8470091, 20.1719512) ( 60d50'49.23"W, 20d10'19.02"N)<br>
Center ( -95.4751980, 36.4894554) ( 95d28'30.71"W, 36d29'22.04"N)<br>Band 1 Block=2606x1 Type=Float64, ColorInterp=Gray<br> NoData Value=-99999<div><br></div><div>I have tried running the GrADS-produced GeoTiff through 'gdalwarp' to produce the same boundaries and CRS, as well as adding the NoData and removing the TIFFTAG meta tags. None of these attempts have improved the display.</div>
<div><br></div><div>The obvious question you might ask is, why not just use GDAL then?</div><div>Short answer: GrADS can create "derived products" from the GRIBs I am processing much easier than I can with GDAL using gdal_translate, gdalwarp and gdal_calc.py. I must use GrADS which will create a "control file" for the metadata of my GRIBs, allowing the batch process itself to create my derived products from a combination of "base products" (bands inside the GRIB).</div>
<div><br></div><div>I welcome any and all feedback. Thanks for your time.</div></div>
</blockquote></div><br></div>