ArcGrid Raster MetaData display and export

msperlin

I'm trying to export elevation data from ArcGrid raster to to DTED Level 0. The ArcGrids were set up to have the same extents as a DTED0, so there would be no shifting of data.

Problem is that multiple DTED0 files are created from each ArcGrid, where only one of the DTED0 files is as expected, and the others are no data. In my test case, files are created for each latitude 18 through 35, longitude -120.

It appears that GM is using the incorrect South and Lower Right extents for the ArcGrid.

Attached is zip of ArcGrid.

The input Arcgrid metadata in ESRI ArcGis shows:

<dataExt>
<geoEle>
<GeoBndBox esriExtentType="native">
<westBL Sync="TRUE">-120.004167</westBL>
<eastBL Sync="TRUE">-118.995833</eastBL>
<northBL Sync="TRUE">36.004167</northBL>
<southBL Sync="TRUE">34.995833</southBL>
<exTypeCode Sync="TRUE">1</exTypeCode>
</GeoBndBox>
</geoEle>
</dataExt>
<geoBox esriExtentType="decdegrees">
<westBL Sync="TRUE">-120.004167</westBL>
<eastBL Sync="TRUE">-118.995833</eastBL>
<northBL Sync="TRUE">36.004167</northBL>
<southBL Sync="TRUE">34.995833</southBL>
<exTypeCode Sync="TRUE">1</exTypeCode>
</geoBox>


Looking at the Global Mapper Meta-Data display for the same Arcgrid, it shows:

FILENAME=C:\test\n35\w001001.adf
DESCRIPTION=n35 GRID (w001001.adf)
UPPER LEFT X=-120.0000000000
UPPER LEFT Y=36.0000000000
LOWER RIGHT X=-119.0000000000
LOWER RIGHT Y=18.9416666667
WEST LONGITUDE=120.00000000° W
NORTH LATITUDE=36.00000000° N
EAST LONGITUDE=119.00000000° W
SOUTH LATITUDE=18.94166667° N
PROJ_DESC=Geographic (Latitude/Longitude) / WGS84 / arc degrees
PROJ_DATUM=WGS84
PROJ_UNITS=arc degrees
EPSG_CODE=4326
COVERED AREA=72360 sq mi
NUM COLUMNS=121
NUM ROWS=2048
PIXEL WIDTH=0.00833 arc degrees
PIXEL HEIGHT=0.00833 arc degrees
MIN ELEVATION=58 meters
MAX ELEVATION=1540 meters
ELEVATION UNITS=meters
BIT_DEPTH=24

global_mapper

I took a look and found there is conflicting information in the grid file headers. The bounding box file has the correct bounds, but the pixel size calculated based on the bounding box and the pixel size (121x121 samples in this case) is quite different than the pixel size calculated using the tile size and tile counts (or 121x2048). In other cases where these are inconsistent the appropriate behavior was to grow the bounding box, although in this case it looks like what would be best would be to ignore the erroneous tile size parameter.

I have updated the importer to be smarter in the cases of these inconsistencies and now your data loads as expected. I have placed a new build at http://www.globalmapper.com/global_mapper11.zip with the change for you to try. Simply download that file and extract the contents into your existing v11.xx installation folder to give it a try. If you are using the 64-bit version, there is a new build available at http://www.globalmapper.com/global_mapper11_64bit.zip .

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

msperlin

Fix worked as expected.

Thanks for your quick response.

Marv