need cheap or free rf propagation & Terrain Analysis sof

radioinstl · Post by **radioinstl** » Wed Sep 22, 2004 6:00 am

local vfd looking for some cheap or free (shareware) rf propagation and terrain analysis software, have new channel and equipment and need to evaluate what site to put it on. Have limited money due to cost of equipment going up and want to get the best site we can for long term use. thanx

RKG · Post by **RKG** » Wed Sep 22, 2004 7:08 am

I don't believe there is such a thing.

There is a guy in Canada (search for "Radio Mobile") who purports to have a shareware propigation program out there, but so far as I'm aware, no one has successfully made it integrate with popularly available terrain data (such as that sold by DeLorme).

Post by **HumHead** » Wed Sep 22, 2004 7:38 am

Actually, I have been playing with Radio Mobile quite happily. After the demise of Mapblast, they updated it to take overlay data from a number of new sources, including topo, road maps, and aerial imagery including SRTM, MapQuest, Map Point, Toporama, and Terraserver.

Personally, I'm currently using Shuttle Radar Terrain Mapping 1 arc second data for topo, overlaid with MapQuest maps for streets and boundries.

It is not exactly an intuitive program, and you have to go to third party sites for instructions and support but, if free is your price range, it's about the only game in town.

In fact, once you get past learning the interface, and the lack of documentation, it's actually pretty remarkable for a piece of freeware.

Here's the main web site for Radio Mobile: http://www.cplus.org/rmw/english1.html

nmfire10 · Post by **nmfire10** » Wed Sep 22, 2004 8:50 am

I tried using that Radio Mobile program once before a long time ago. Wow, I was pulling my hair out trying to get the data to work. Maybe I try it again now that it can use other forms of data.

nmfire10 · Post by **nmfire10** » Wed Sep 22, 2004 7:14 pm

Wow, this actually works now!

What is a good % loss to put down for a heavily forested rural area? I am using 25% right now and it seems somewhat accurate.

radioinstl · Post by **radioinstl** » Wed Sep 22, 2004 7:25 pm

i have only three site to check if some one has the software already and is willing to run the numbers that would be awsome. i have lat/long height watts ERP etc any help would be great pm or email me.

RKG · Post by **RKG** » Thu Sep 23, 2004 9:04 am

Fractional propigation loss for forested areas depends on the band, time of year, and whether the forest is evergreens or trees that shed leaves in the fall. The near field effect on 800 in the summer can be severe, though I'm not aware of any rule of thumb values for use in propigation programs.

nmfire10 · Post by **nmfire10** » Fri Sep 24, 2004 5:40 am

I'm having an issue with the steet or topo map overlay not llining up with the terrain data map. It seems like the map overlays are 1/2 miles south-west of where they are supposed to be. Any ideas?

RKG · Post by **RKG** » Sun Sep 26, 2004 5:20 pm

Datum mismatch. See if one data set is based on "NAD27" and the other is basedon "NAD87/WGS84".

nmfire10 · Post by **nmfire10** » Mon Sep 27, 2004 3:50 am

The DTED elevation data had the problem. I tried using SRTM instead and it worked perfect. I'm loving this program. I know it isn't an exact science but it is nice to get a visual representation of something close to what will work.

need cheap or free rf propagation & Terrain Analysis sof

need cheap or free rf propagation & Terrain Analysis sof

thanx for the anwsers