[FWTools] calculate from meters to feet

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I'm in the process of exporting the US NED 10 meter DEM in ArcInfo GRID format to bigtiff using GDAL utilities. The grids are generally tiled into 1x3 degree areas. The Z units are stored in meters, my desired output will be feet. I would first like to recalculate the Z values before doing any other processing. 

In ArcInfo TIN, I'd normally use the latticeoperate command for this procedure. On these 1x3 degree tiles the latticeoperate command is not working, previously I processed these grids to 7.5 minute tiles and have already updated the Z values using the latticeoperate command on those smaller tiles.

I'm trying to balance storage, speed, and precision thus the desired output of the bigtiff is feet as INT16. 

So I really have two questions right now. Since my goal is to merge all the tiles into the bigtiff I've decided it would be best to process the raw 1x3 degree grids delivered to us. Is there a gdal utility for converting the Z value from meters to feet?

Alternate question would I be better off exporting from my 7.5 minute tiles already processed then translate and merge (examples below)? 

Here are my steps so far (leaving the data in meters). I will be exporting the entire dataset later not just area 18 as in the example.  Definately need to get the Z value modified before converting to INT16.

 
gdal_translate -ot
Int16 demgrid_018_1 demgrid_018_1.tif  ( and _2, _3)
 
gdal_merge -o
area18a.tif demgrid_018_3.tif demgrid_018_2.tif demgrid_018_1.tif --config
BIGTIFF YES

thanks for your time.

Zach-



 Zachary Fisk 

"A tax supported, compulsory educational system
is the complete model of the totalitarian state."
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"All truly wise thoughts have been thought already thousands of times;but to make them truly ours, we must think them over again honestly,till they take root in our personal experience."
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