Issues with Exporting DTED1 from a GeoTiff

cabice89

Good Afternoon,

I am having issues exporting GeoTiff to DTED1. It is a large Elevation geotiff of the Continental US. The input DEM has no noticable anomalies.

My issue is that I am getting significant "shelves" of 8-15 meters on the borders of geocells, especially in areas of high relief. Is there any way to feather these? I have tried using the feather function and then exporting to no avail.

It happens in the Arc, Terra Tools, and ERDAS exports as well.

Any help is appreciated.

global_mapper

Are you seeing the shelves just when you load the terrain tiles back into Global Mapper? There is a display issue where the interpolation and shadowing doesn't normally use adjacent data sets, so you may get a shadow border along the tile edge. This isn't actually a problem in the data, just a render artifact.

You can get the shadowing and interpolation to cross tile boundaries by loading the tiles in a map catalog (File->Create New Map Catalog). That way GM knows the tiles are part of the same data set and will interpolate across them.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Guru
geohelp@bluemarblegeo.com
Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation

cabice89

Thanks for the reply, Mike.

You are correct. Here is my workflow thus far:

1. load GeoTiff into GM
2. Export to DTED1
3. Reload DTED1 Tiles in

This is where I am seeing the vertical tears.

I have tried your method of loading the tiles into a map catalog and am still seeing elevation shelving when I export those tiles out with the feathering turned on. Is there a better way to do this? I have been trying everything I can think of.

CB

global_mapper

Are the vertical "tears" completely missing columns or rows or a discontinuity? Also when you created a new map catalog with the tiles, did you unload the original tiles (if loaded)? Also what version of GM are you using? When I tried this with the latest I saw the edge render discontinuity (a visual artifact only) when loaded individually, but not when loaded from a map catalog.

Thanks,

Mike
Global Mapper Guru
geohelp@bluemarblegeo.com
Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation

vishnuaarthi

Hi,

Ditto the same issue vertical tear appears between tiles.Here is my flow

1.Import single geotiff file

2.Export the tiles using selected grid-Crop to selected area features

3.Reload the exported geotiff files

My version is v22.1

Any help is appreciated