[Geotiff] DEM in a GeoTIFF

[Norman Barker]

Mike wrote:

>We're looking to optionally encode DEM data in a GeoTIFF but have not 
>found much in the way of information on this.  Encoding the data 
>itself isn't a problem but encoding the tags correctly is a concern.  
>We also have DEMs where the horizontal and vertical units are 
>different and want to preserve that data.
>
>Can anyone point us to example GeoTIFF DEMs or any "standards" for 
>encoding this type of data in a GeoTIFF?
>
>Thanks,
>--Mike
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>Geotiff at remotesensing.org
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>  
>
Hi,

an unofficial sample is the USGS geotiff DEMs, the description is below

USGS digital elevation model, GeoTIFF format

Description: elevation data derived directly from USGS native format 
DEM's. This is an experimental format and is not available for sale. 
GeoTIFF DEM's are implemented as 16-bit TIFF images to preserve absolute 
elevation values. 16-bit data, while allowed by the TIFF 6.0 standard, 
is not widely implemented in TIFF viewers, so these files may or may not 
be viewable in other software.

Available for free download? No. DEM data in GeoTIFF format is not a 
USGS product.

Web pages, ftp sites: none

Sample data:

    ftp://ftpmcmc.er.usgs.gov/release/viewers/sample_data/dem/geotiff

A great way to server your DEM geotiff data is through a Web Coverage 
Server.  Deegree unfortunately has a problem
with 16 bit data (at the moment anyway), but MapServer WCS is very cool.

HTH,

Norman