Has anyone created a coverage map for one of there customers? Our county fire repeater system has many "holes" and in some areas are Mobile radios only, others both mobile and portable. I think it would be really cool to create a type of coverage map for my area using Google Earths elevation feature. If anyone has done this before I would love some pointers and if you know of an easier way to do it please chime in.
David
Creating a Coverage Map
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turbovectorz
- Posts: 36
- Joined: Sat Nov 29, 2008 5:11 pm
- What radios do you own?: Sabers, homebrew scanners
Re: Creating a Coverage Map
Hi,
When I consulted for Verizon/AirTouch/Vodafone, I combined aerial maps and USGS maps for RF Propagation Surveys. However, you can use the http://www.acme.com/mapper and make your own coverage maps.
Make sure you define all your RF specifications for test and measurement though.
I have also had great success also using this for DMR and Cellular projects.
Hope this helps!
Sincerely,
TVZ
When I consulted for Verizon/AirTouch/Vodafone, I combined aerial maps and USGS maps for RF Propagation Surveys. However, you can use the http://www.acme.com/mapper and make your own coverage maps.
Make sure you define all your RF specifications for test and measurement though.
I have also had great success also using this for DMR and Cellular projects.
Hope this helps!
Sincerely,
TVZ
Re: Creating a Coverage Map
The best way would be to use a terrain mapping program. Softwrite is one program I have used in the past. It
requires you to input some information like TX power, antenna gain, antenna direction and feedline loss. I then
uses the terrain data and will generate a colored map showing the signal strength in the coverage area.
Only draw back to the program is the cost of it and also obtaining the terrain data to use. If I remember
the cost of the software is around $5 k to $10 k depending on the options you get.
There are other programs out there that do a good job. I believe that there is even a share ware package.
Don't do that kind of work any more so have lost track of it.
Jim
requires you to input some information like TX power, antenna gain, antenna direction and feedline loss. I then
uses the terrain data and will generate a colored map showing the signal strength in the coverage area.
Only draw back to the program is the cost of it and also obtaining the terrain data to use. If I remember
the cost of the software is around $5 k to $10 k depending on the options you get.
There are other programs out there that do a good job. I believe that there is even a share ware package.
Don't do that kind of work any more so have lost track of it.
Jim
dsheli wrote:Has anyone created a coverage map for one of there customers? Our county fire repeater system has many "holes" and in some areas are Mobile radios only, others both mobile and portable. I think it would be really cool to create a type of coverage map for my area using Google Earths elevation feature. If anyone has done this before I would love some pointers and if you know of an easier way to do it please chime in.
David
Re: Creating a Coverage Map
Radio Mobile, while being a bit obtuse to use, does a great job and is free. 1 arcsecond SRTM data can be had for free (well, you've already paid for it with tax money) from NASA. Such a program uses science, math, and terrain data to figure out what the repeater "should" do. It is not perfect... real system installs include driving studies which confirm what the mapping program shows. However, if you have everything configured properly and the coverage is significantly different than what RM indicates, you can conclude something is likely wrong...
Re: Creating a Coverage Map
Wow, after doing a little more research this is definitely going to be a daunting task. Thanks for all the input! I will keep everyone updated.
David
David
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turbovectorz
- Posts: 36
- Joined: Sat Nov 29, 2008 5:11 pm
- What radios do you own?: Sabers, homebrew scanners
Re: Creating a Coverage Map
Hi David,
The very least you can do is a perform a drive test (along with an associate)with a RF Service Monitor connected to your laptop (via serial or USB port) to collect RF signal strengths (dB) data along with a GPS receiver and data collection software (or make your own!). Later you can calculate the dBm in relation to a reference antenna and plot the results in your coverage map. You can also perform much more sophisticated analysis using mathematical-based software packages such as Matlab, MathCAD, and Mathematica.
by the way, what frequency band? UHF 400, 450, 800 MHz?
Hope this helps!
Sincerely,
-- TVZ
The very least you can do is a perform a drive test (along with an associate)with a RF Service Monitor connected to your laptop (via serial or USB port) to collect RF signal strengths (dB) data along with a GPS receiver and data collection software (or make your own!). Later you can calculate the dBm in relation to a reference antenna and plot the results in your coverage map. You can also perform much more sophisticated analysis using mathematical-based software packages such as Matlab, MathCAD, and Mathematica.
by the way, what frequency band? UHF 400, 450, 800 MHz?
Hope this helps!
Sincerely,
-- TVZ
Re: Creating a Coverage Map
Once you have your drive-around data (RSSI/SINAD plus GPS coordinates), use Python or Perl to convert it to KML format (take a look at http://code.google.com/apis/kml/documen ... l_tut.html)
You can load the resulting KML/KMZ file into Google Earth and show the received signal strength on the driven path, it is much easier (and better eye-candy) than trying to make your own map.
I believe that it is also possible to set the color of the path using tags so you should be able to highlight the "holes"
You can load the resulting KML/KMZ file into Google Earth and show the received signal strength on the driven path, it is much easier (and better eye-candy) than trying to make your own map.
I believe that it is also possible to set the color of the path using tags so you should be able to highlight the "holes"
Re: Creating a Coverage Map
tvsjr wrote:Radio Mobile, while being a bit obtuse to use, does a great job and is free. 1 arcsecond SRTM data can be had for free (well, you've already paid for it with tax money) from NASA. Such a program uses science, math, and terrain data to figure out what the repeater "should" do. It is not perfect... real system installs include driving studies which confirm what the mapping program shows. However, if you have everything configured properly and the coverage is significantly different than what RM indicates, you can conclude something is likely wrong...
Using Radio Mobile does require a little work, but once you get it set up it produces some very nice maps that you can overlay on political or highway maps. You will need to play with the settings to get a representation of what you know to be true. Once you have that, then it will give a fair prediction of the areas you don't know so much about. I have found that it does over predict the effects of gain, and remember that the antennas of hand helds are negative gain antennas. The last thing you want to do is over predict coverage, because you won't look very smart if the system doesn't work like you said it would.
Where radio mobile does an excellent job is predicting the effectiveness of point-to-point links because you can look at the path horizontally and see if there are any obstructions and how much clearance you have.
Wyrd bið ful ãræd, Fate is inexorable...
Re: Creating a Coverage Map
One correction... that should be any natural obstructions.ai4ui wrote:Where radio mobile does an excellent job is predicting the effectiveness of point-to-point links because you can look at the path horizontally and see if there are any obstructions and how much clearance you have.
Never underestimate the idiocy of a tech who has just such a path profile and fails to account for the multi-story building in the way!
Re: Creating a Coverage Map
Wow guys thanks so much for your replies. This is definitely going to be a daunting task and your help is much appreciated. I think what I am going to do is use radio mobile and try and come up with a decent coverage map. Like you said there are areas I know to be of no coverage, and areas of good coverage. If I can give this to my FF and first responders they will at least have an idea of where they can call county when they don't have access to a mobile radio. I will be sure to keep you guys updated on how the project goes, and may bee, if I have time try and type up a tutorial. This will definitely be a huge learning curve for myself, I plan on starting this project mid august when I get back from a family vacation. Again thanks for the replies guys!
David
David
Re: Creating a Coverage Map
I second the choice to use Radio Mobile. It is an excellent program, well supported, and very accurate. I use it constantly. There is a learning curve, but not bad. The 1/3 arcsecond corrected datum is now available for free, and yields excellent PtP coverage plots for wifi and wireless bridges. The one arcsecond datum is sufficient for wide area radio systems.