SDR Heatmaps

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24MHz - 124MHz

This heatmap was generated in February 2017 from Bucharest, Romania. It was captured with 3 RTL SDRs connected to wire antennas of different lengths. The heatmaps are actually on different layers and can be selected with button from the top left corner. Around 27MHz you can see some HAMs (radio amateurs) chatting. Between 88-108MHz you can clearly see the FM station. I don't know what the other signals are, but if you do, let us know so we can add it to the description.

100MHz - 200MHz

This heatmap was generated in February 2017 from Bucharest, Romania. It was captured with 3 RTL SDRs connected to wire antennas of different lengths. The heatmaps are actually on different layers and can be selected with button from the top left corner. Until 108MHz you can clearly see the FM stations, and between 166-174 MHz there is a lot of narrow FM taxi chatter. A huge amount of noise and some reflections can be observed at ~125MHz. Other small signals are very visible but that's enough spoilers.

200MHz - 300MHz

Just like before, it was captured with 3 RTL SDRs connected to wire antennas of different lengths. I think the first 1/3 of the heatmap is actually a DVB-t signal but I couldn't say for sure.

300MHz - 400MHz

This heatmap was captured with 3 RTL SDRs connected to wire antennas of different lengths. The heatmaps are actually on different layers and can be selected with button from the top left corner. There are a lot of interesting signals in this part of the radio spectrum. If anyone knows what they please share the knowledge.

400MHz - 500MHz

This heatmap was generated in February 2017 from Bucharest, Romania. It was captured with 3 RTL SDRs connected to wire antennas of different lengths. Here you can clearly see a lot of activity ~434MHz. These are mostly radio thermostats, garage doors remotes, smart meters and some other low tech devices.

500MHz - 600MHz

Just like the others, it was captured with 3 RTL SDRs connected to wire antennas of different lengths. Here you can clearly see a lot of activity 542-550MHz. I think this is a DVB-t (digital TV) signal. There is another very interesting signal at the end of this spectrum but I have no idea what is this. Only one of the 3 dongles was able to receive it, perhaps because the antenna of the dongle that received this signal is horizontal.

600MHz - 700MHz

We have at least 3 interesting signals here, at ~ 621, 668 and 692MHz. Anybody has a clue what these are?. Again the dongle with the horizontal antenna was able to detect the most signals.

700MHz - 800MHz

This heatmap was generated in February 2017 from Bucharest, Romania. It was captured with 3 RTL SDRs connected to wire antennas of different lengths and with different orientations. At the end of this spectrum you can see a part of a signal where normally I would expect LTE, but it looks a bit strange for that. In the first part there is something that appears only on the first radio but I couldn't say for sure what is that.

800MHz - 900MHz

This one was also captured with 3 RTL SDRs connected to wire antennas of different lengths and with different orientations. Normally here I would expect to see 4G mobile network signals here but apparently in Romania we use a different frequency for those. Nevertheless, you can see some intermittent signals at 868MHz.

900MHz - 1000MHz

This heatmap was captured with 3 RTL SDRs connected to wire antennas of different lengths and with different orientations. The first half of this spectrum is mobile phone communications (2G network). To me, this looks like one of the most beautiful heatmaps :)

1000MHz - 1100MHz

Also captured with 3 RTL SDRs connected to wire antennas of different lengths and with different orientations. This spectrum is very quiet here but there is a very interesting signal at 1047.5MHz. Of course, at 1090MHz there are the ADS-B signals which allows us to track the position of airplanes.