Every airliner above 18,000 feet broadcasts its own GPS position once a second on 1090 MHz, unencrypted and unauthenticated, and a thirty- dollar dongle is enough to receive it. We walk what ADS-B actually is on the wire, why hobbyists ended up running the world's biggest flight-tracking network, how FlightAware and Flightradar24 fuse the feeds, and the honest privacy and security implications of broadcasting every plane's position in clear.
Radio
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ADS-B and Tracking Every Plane in the Sky -
How GPS Computes Your Position GPS is one of the few consumer technologies that would fail within minutes if Einstein had been wrong. We walk the physics of fixing your position from four orbiting atomic clocks, why four and not three, the special- and general-relativistic corrections baked into every receiver, how the C/A code lets a phone hear a signal weaker than thermal noise, and why your first fix is slow and the next one is instant.
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LoRaWAN for Long-Range IoT LoRaWAN sells itself as kilometers of range from a coin cell, and the pitch is true — but only because chirp spread spectrum trades bandwidth and airtime for link budget in ways most builders never think through. This post walks the CSS modulation, the spreading-factor and airtime math, the star-of-stars architecture, duty-cycle regulations, and where LoRaWAN genuinely beats Wi-Fi and cellular versus where the marketing outruns the physics.
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The Fourier Transform, Finally Intuitive Any signal is a sum of sinusoids — that one sentence unlocks audio codecs, Wi-Fi, 5G, oscilloscopes, and JPEG. This post builds the Fourier transform from first principles, explains why the naive DFT is impractical and the FFT fixes it, covers windowing and spectral leakage, and shows the whole thing in working Python.
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How Cell Networks Actually Work: 1G to 5G From analog FM and the 1947 Bell Labs cellular concept to massive MIMO and network slicing — what each generation actually changed in the air interface, how handoffs work at 70 mph, what a SIM really is, and why 5G coverage maps still disappoint.