Introduction
Radio Mobile Online is a radio wave propagation prediction tool dedicated to amateur radio.
It uses digital terrain information and a mathematical model to simulate radio transmissions between two fixed sites (radio link) or between a fixed site and a mobile (Radio coverage).
The digital terrain information comprises three databases: ground elevation, land cover, and population density. Those databases are located on the server and represent a total of 200 GigaBytes.
The mathematical model predicts the radio transmission performance based on the following entries:
Transmitter power
Transmitter line loss
Transmitter antenna gain
Transmitter antenna type (for coverage only)
Transmitter antenna azimuth (for coverage only)
Transmitter antenna tilt (for coverage only)
Transmitter antenna height
Transmitter latitude
Transmitter longitude
Transmitter ground elevation
Elevation data records between the transmitter and the receiver sites (up to 2000 records)
Land cover data records between the transmitter and the receiver sites (up to 2000 records)
Receiver latitude (for link only)
Receiver longitude (for link only)
Receiver ground elevation (for link only)
Receiver antenna gain
Receiver antenna height
Receiver line loss
Receiver sensitivity (corresponds to the receiver threshold)
Required reliability (The percentage of time where the signal must be above the threshold to consider a link to be liable).
Color for a successful reception (for coverage only)
Strong signal margin (for coverage only)
Color for a successful reception with a strong signal (for coverage only)
Transparency of the ground overlay (for coverage only)
The mathematical model is a mix of the ITM model, the two rays method, and the land cover path loss estimation.
The ITM model is a US government publication, public domain. The two rays method and landcover path loss estimation are based on my 40 years experience in radio propagation.
For a Radio Link study, the output of the mathematical model predicts success if the fade margin of the received signal is greater than zero.
For a Radio Coverage study, a colored plot over a topographical map is produced.
For more information see:
ITM model documentation
The author cannot be held responsible for the quality of the predictions, the usage, or the lost of data due to a failure of the server.
Users who wants to publish the result of their work must comply to the rules dicted by the background map provider.
Roger Coudé VE2DBE
Difference between the freeware and the online version
Radio Mobile freeware is a stand alone application running on a Windows based computer.
It is a powerful tool but it is not easy to set up.
A large amount of data must be downloaded from the internet to build the elevation and land cover databases required by the model.
It can be very slow when performing high resolution coverage calculations depending on the computer speed.
The online version has some limitations also: it depends on an internet connexion, and it is limited to amateur radio bands.
But the nice things are:
Run from your internet browser, on any software platform such as Windows, Linux, Mac, and devices like Ipad, smart phones, etc.
User entries have been simplified to a minimum
Positioning simplified and improved thanks to OpenLayers
You no longer need to download huge amount of data and find the proper source for your area
The best data available is used worldwide in a seamless transition
Only a very small amount of data is exchanged between the server and your browser
It is multithread capable (Actually limited to two threads per user)
The coverage calculation are much faster than the original program, producing pixel wise images.
The outputs of the program are nice and can be imported to your computer
All your studies are kept on the server
Create your own free account
A private account is required to use Radio Mobile Online. A link is provided on the main page in order to create your own account.
Since the user name is used to create the directory structure associated to your account, it is important to have a user name that follows the server syntax rules:
the user name should not include special caracters such as space, dot, comma, etc.
Your amateur callsign is probably the best username possible.
If no site has been defined 10 days after the account creation, the account will be deleted.
Frequencies allowed (MHz)
From
To
10
30
50
54
70
70.5
144
148
222
225
420
450
462.5625
462.7125
467.5625
467.7125
863
870
902
928
1240
1300
2300
2310
3300
3500
5650
5725
5825
5925
10000
10500
24000
250000
Importing units
Radio Mobile online can import and export a list of units in CSV text format.
As an example, you can use the export button in Radio Mobile Units properties to export a group of units in a txt file format.
You then open the text (txt) file with Excel (or other calculator program) and keep only the Name, Latitude, and Longitude columns.
Also remove the title line.
You then save it as a CSV text file that you can import using the file selection and import button in the "My sites" panel of Radio Mobile online.
The elevation will be extracted automatically for each unit.
Population covered
When performing a radio coverage study, the program access a population density database to determine the total population covered for both levels of signal.
The quality of that database varies from one country to another. The database has a resolution of 30 arseconds and was derived from
SEDAC - Columbia University.
Red >=1000 (inhabitants per square kilometer), Orange >= 500, Yellow >= 100,
Green >= 50, Turquoise >= 10, Cyan >= 5, Purple >= 1, Blue >= 0, Black = 0
Coverage files
When viewing a saved coverage study with "My coverages" there is a link to a zip file at the bottom of the page.
That file can be saved to your local computer and contains the following geo-referenced pictures:
Coverage picture (Transparent PNG)
Terrain picture (_ELV.JPG)
Landcover picture (_CLU.PNG)
Population picture (_POP.PNG)
All those pictures can be viewed in Radio Mobile and used as merge source.
The coverage picture can be viewed in GoogleEarth by modifying the .zip file extention to .kmz .