TV Reception Terrain Map

Every now and again, a website comes along which is genuinely very useful. The Megalithia Terrain website produces a map which shows the terrain and distance between your house and the TV transmitter you are tuned to.

The directions on the website are pretty good, but it’s useful to have a walk-through as it’s a bit complicated.

The first thing you need is the National Grid Reference (NGR) for your house. You can find this by visiting and searching for your postcode. Once the map appears with the big orange arrow, go to the bottom of that page and find the “Click here to convert coordinates link”. I seemed to have problems getting this to work with Firefox, but IE seemed to render it fine.

On the next page is a list of various styles of coordinates for your location. I searched for the postcode “SO21 2JN” (actually where I work). The field you’re looking for is the one marked “LR”. In my case, this is “SU422254”. Note that down and then return to the Megalithia website. 

Now at the bottom of the terrain website is where you enter the details of the transmitter you’re using. I selected the region “Southern England”, and then the transmitter “Rowridge”, which is on the Isle of Wight. The transmitter is referred to as the “distant” station – changing the transmitter modifies the distant station NGR field. Enter your home NGR into the “base station” field and then click “go”.

This will produce a simple graph showing the height of the base station on the left (you), with the TV transmitter mast on the right.