A beginner's guide to Software Defined Radio — the technology behind AwareSignal, and how three dedicated USB dongles listen to aircraft, weather satellites, and everything else in the air above Doncaster.
SDR stands for Software Defined Radio. A traditional radio is built for one job — an FM radio only receives FM, a police scanner only receives certain bands. An SDR is different: it's a simple receiver that hands the raw radio signal straight to software on a computer, and the software decides what to do with it. The same £20 dongle can listen to FM radio, aircraft, weather satellites, or hundreds of other things, just by running different software.
How it works
01
The antenna receives radio waves
Everything in the air — FM radio, aircraft signals, satellite broadcasts — is a radio wave at a different frequency. The antenna picks all of it up.
02
The SDR dongle converts it to digital
Instead of a traditional radio circuit tuned to one frequency, the dongle samples the raw signal and turns it into digital data the computer can read.
03
Software does the tuning and decoding
Software picks which frequency to focus on and decodes whatever's there — voice, aircraft position data, or a satellite image.
04
AwareStation pushes the data live
The decoded data gets processed and pushed to this site every 30 seconds — aircraft positions onto a map, satellite signals into images, and radio detections into a log.
The AwareSignal three-dongle setup
AwareStation uses three separate SDR dongles, each with its own dedicated antenna, running independently so they never conflict with each other. Each one does exactly one job, all day, every day.
✈ SKYTRACK
Dedicated ADS-B aircraft receiver — tracks every commercial flight within range in real time.
Antenna: ADS-B specialist antenna
Frequency: 1090 MHz
Protocol: ADS-B Mode S
Output: Live aircraft radar
🛰️ ORBIT
Satellite receiver — automatically captures and decodes weather satellite images from Meteor-M2-4 and ISS passes.
Wideband general scanner — continuously sweeps FM radio, aviation voice, marine VHF, emergency beacons, and ISM bands. Also watches every sweep for solar radio bursts.
Antenna: Discone (wideband)
Frequency: 88 MHz — 870 MHz
Protocol: FM / AM / NFM
Output: Live signal log + solar watch below
What CORE is currently detecting
No signal detections logged yet — CORE is scanning and will populate this table automatically.
☀ Solar Burst Watch
Alongside the normal per-frequency scan above, CORE also checks each full sweep for a different kind of pattern: instead of one frequency spiking, a genuine solar radio burst shows up as many channels going elevated all at once — a broadband event rather than a local transmitter. When that happens, it's logged as a candidate below and automatically cross-checked against NOAA's live GOES X-ray flare data, so you can see whether a real confirmed solar flare was actually happening at that moment.
No solar burst candidates yet — CORE checks for this after every full sweep and will populate this table automatically if one is detected.
Frequencies AwareSignal listens to
Frequency
Dongle
What it carries
88–108 MHz
CORE
Regular FM radio stations
118–137 MHz
CORE
Aviation voice — pilots talking to air traffic control
137 MHz
ORBIT
Meteor and NOAA weather satellites broadcasting live images
ADS-B — every commercial aircraft broadcasting its own position
Why this might interest you
Radio signals are invisible but follow exact, predictable rules — the same frequency always carries the same kind of thing, the same satellite always passes at a calculable time, and the data is real and live rather than simulated. For anyone who enjoys patterns, systems, and watching real-world data update in real time, SDR turns the empty sky into something you can actually see and track.
