So I’ve been collecting data from the Raspberry Pi radar station for about a week and a half now, and following a move of the antenna to the top floor of the house, I’ve gone from collecting about 5,000 datapoints a day to over 25,000. Seems that ADS-B really is line of sight with no exceptions! So, now that the amount of data is starting to build up, I thought I’d start to work on what kinds of questions to ask the database. Of course, the obvious ones came to mind first: What’s the highest thing you’ve seen, and what’s the fastest thing you’ve seen?
Turns out that I managed to catch a Turkish Government owned Gulfstream jet (TRK5) as it passed over Wiltshire and South Gloucestershire:
Throwing the co-ordinates into Google Maps shows that the jet was just North of Cirencester at the time:
From the very high, to the very fast: It seems that United Airlines flight 989 may have been getting a bit of an assist from the winter Gulf Stream. A ground speed of over 600 knots (just shy of 700mph) is 90% of the speed of sound.
However, it’s important to note the difference between airspeed and ground speed. With a significant tail wind, the aircraft will be travelling through the air at a much lower speed than it is travelling across the ground. The pilots of a commercial airliner would never risk getting close to the speed of sound and outside the structural limits of their aircraft. For more info on events like this, take a look at this newspaper article.
I’m still thinking of more interesting questions to ask – such as average speeds over time for a scheduled flight, accuracy of flightpath e.g. over a month of scheduled flights, does the aircraft vary left and right of its planned route, and if so by how much, and if so is there a pattern to it? I’m also keen to perhaps look at ways to enrich the data with other sources of information perhaps on winds aloft, temperatures and so on. Watch this space…