Any computer GIS people out there?

“I've got a few questions for someone who is familiar with GIS. Specifically using DEM (Digital Elevation Model) files.”

“I might be able to help.

What would you like to do with the DEM?”

“I might be able to help.

What would you like to do with the DEM?”

“I might be able to help.

What would you like to do with the DEM?”

“Go to usenet.

sci.geo.satellite-nav.

Sam Wormley is an expert on such matters.”

“Echo, Echo!

This website is very helpful”

“My goal is this:
Given a lat/lon coordinate, find the elevation. I figure I could use the DEM to do that. Funds are a problem, basically non-existant. So I thought I might be able to program something that reads in the DEM, and then finds the appropriate elevation. Is that doable? I am just starting to learn about all the file formats and programs available.”

“Have you done a search on the DEM file format specification? That should tell you pretty quickly whether what you want to do is possible or not.

I played around with some DEM's a couple of years ago, and found that the file format has changed a couple of times. Most of the DEMs I looked at were aligned with USGS quads, so the lat/long of the corners should be well known.”

“Here's a file I found that claims to have the DEM file format spec in it. It's a zip file.”

“Oops, wrong DEM.

Try here, it's the USGS site.”

“Matt, I'll ask our GIS department your question.”

“I wish they had a GIS program when I was in skool.

A BIG field it is.”

“Yet a field that doesn't seem to be making my company too much money. Hard to get that group to stand on their own. Municipalities don't want to spend the money to "make pretty maps". Our GIS group is basically a support to the rest of the company here, especially my group, which uses all kinds of GIS data for our modeling work (storm systems, sanitary and water systems, flood plains, etc.)”

“Short answer is yes it is "doable". Not sure they need to program something. Depends on how many points and what "basically non-existant" really means. There are free and almost free programs out there that will let people view DEM's and get info from them.”

“smiley,
thanks for your help. I have a dataset of lat/lon points (thousands of points) that I want to find the elevation of. I don't want to have to look up each point by hand, that is why I was thinking of having some program that I can feed coordinates into and have it spit out the elevation.”

“no problem matt. i love our GIS dude. he makes my life so much easier, and he knows his #&%!$.

you can shoot me an e-mail if you need more info.”

“Matt,

There is a program that used to be shareware but now appears to be freeware HERE. This thing may or may not do what you want but it could save you a lot of work if it does!

Let us know if it works for you...”