We were asked recently by a customer in Haiti to make some coverage plots from a particular site in the south of the country from the side of a mountain. We’ve been doing these plots quietly for years. We make them by using NASA’s Shuttle Radar Topography Mission or SRTM data collected from a mission in the year 2000. NASA and the US Government kindly made this available for companies like ourselves to use 🙂


The Shuttle Radar Topography Mission (SRTM) was an international research effort that obtained digital elevation models on a near-global scale from 56° S to 60° N to generate at this time the most complete high-resolution digital topographic database of Earth. The data was collected using a specially modified radar system that flew on board the Space Shuttle Endeavour during the 11-day STS-99 mission in February 2000. To acquire topographic data, the SRTM payload was outfitted with two radar antennas. One antenna was located in the Shuttle’s payload bay and the other on the end of a 60-meter mast that extended from the payload bay once the Shuttle was in space. The technique employed is known as interferometric synthetic aperture radar.

Over the years we have made thousands of plots using this data for customers asking us the same and most popular question, “How much range can we get?” This data has enabled us to be able to predict the range and coverage to an accuracy of more than 90% and saved customers thousands of dollars in bad planning.

Back in 2009 the British Army had us making plots for the installation of radio transmitters in Afghanistan. At the time the Army engineer said to us, how do you do this? this is better than anything our tech guys can produce. Obviously we were flattered given the resources of the British Army and we duly continued making the plots for them.

We produce the RF coverage plot, then make a png overlay image file for Google Earth. Once in Google Earth we can tilt north, east, south and west and zoom in and out, it’s amazing.

This latest plot uses our 1600W ERP system in the south of Haiti in the Massif de la Selle mountain range. You can see the north view at the top of this post. Below are the views from the east, south and west.

Paul Hollings.