Need to figure out Line-of-sight, GIS software?

[efurban]

Hi, just wondering if anybody here knows about how to measure line-of-sight?
I have GPS data of point A and point B and I wanna know if there is a line-of-sight in between, my frined mentioned that this can be done by GIS. I just got GIS 9.0 but I have no idea how to do this. Anybody ?

thanks very much.

 

[bleair]

Are you looking for something like google maps to do it for you, or are you writing software?

If you are building your own program I might suggest starting with

http://edcsns17.cr.usgs.gov/srtmdted2/
I recall that they recorded the whole planet in that mission, but I don't know if the data outside the US is available. If you need non-us data, I know that a DTED level 0 data set for the whole planet is available (try google)

DTED is a nice, simplistic format (see http://earth-info.nga.mil/publications/specs/printed/89020B/89020B.pdf)

Do you have your own datasets? You didn't describe your resolution requirements

You also need to decide if you can cheat on your datum, or if you need to use WGS84.

Hmm, come to think of it, you might just be better off going to point A, getting a buddy to go to point B and use a laser pointer of something high tech like that.. 🙂

So what exactly are you doing?

 

[Armitage]

Does it have to be software?
Get yourself a TOPO map. Find the points on it and see if there is anything higher then either point along the line between them. If it's far enough away, you may have to take the curvature of the earth into account ... ie., is it below the horizon.

 

[TStep]

Online Topo Maps
For the simplistic approach

 

[jessieqwert]

Are you using Arc GIS? I know there is a way to do this. Try using the help contents. Arc GIS has the most comprehensive and useful help I've ever seen for software.