Everyone who like VHF/UHF and contesting on this bands must know about this free tool. Yes it’s completely free to use but required a registration.
The website is here and a desktop version is here
Basically it’s tool that helps to predict and calculate a radio wave propagation on amateur bands.
Let’s read more about:
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 land cover 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.
Frequencies allowed (MHz)
For more detailed information please visit his website.
Let’s look at the examples for my QTH at DM04.
And this is an example of Point to Point (Radio Link) prediction.