DEM coordinate question

Started by sonshine777, February 28, 2007, 01:59:50 pm

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sonshine777

I have a question about placing the camera in a terrain that uses a real life USGS DEM.

I work for an engineering firm the also does planning consulting for the National parks system.
The question they have for us is whether or not a small plane would be visible from the ground at specific locations in the parks, in order to set flight restriction areas within the park.

Has anyone used UTM coordinates to place the camera?

Tim O'Donoghue

Are you using TG2 specifically for that purpose, or are you illustrating the views  with TG2 as well?

The reason I ask is that if you are only doing the visibility portion, there may be a better tool. If that is the case, take a look at Global Mapper (http://www.globalmapper.com). Global Mapper does a great job with USGS data and has a graphical viewshed analysis tool built-in. 

On the other hand, if you are using TG2, and simply want to add the other info,, then I'll defer to others mre knowledgeable about TG2. 8-)

Tim O'Donoghue

sonshine777

February 28, 2007, 02:37:42 pm #2 Last Edit: February 28, 2007, 02:42:03 pm by sonshine777
My intention is to use TG2 to do the illustration because they also want trees and structures that may be at the different locations. Basically they want a view looking from the ground into skyline around a location.I will look at Global mapper too. Thanks :)

Oshyan

Everything in TG2 is measured in meters, generally speaking, so with some *simple* math you should be able to figure out your positions relative to the 0,0 coordinate origin in TG, especially if you reference your terrain(s) properly to that origin point - either as a corner or center.

- Oshyan

sonshine777

Being the red blooded American that I am I hadn't wrapped my mind around that yet, Thanks Oshyan! :)

I'll keep you guys posted as to the project progress if they give me the go ahead.

Oshyan

Note that you would need to export your terrain into .ter using a program that was aware of and respected the original GIS/referencing info in the DEM, of course. Global Mapper is ideal for this. I would export the DEM in "native" resolution rather than resampling to a specific size.

- Oshyan

sonshine777

Global Mapper will output to .ter?