Balint Seeber - SDR Tips and Tricks

### Software Defined Radio Beyond Digital Modulation Balint Seeber opens by exploring the underappreciated depth of analog signal processing within Software Defined Radio (SDR). While modern SDR literature overwhelmingly focuses on digital standards like LTE, Wi-Fi, and Bluetooth, analog modulation schemes—including broadcast FM, AM, amateur trunked radio, and legacy video formats—remain widely deployed across mission-critical, industrial, and hobbyist radio environments. Developing custom SDR flowgraphs for analog systems provides foundational insights into RF propagation, synchronization, and baseband reconstruction.

### Analog NTSC Demodulation and Drone FPV Video Seeber demonstrates constructing an analog NTSC demodulator inside GNU Radio. Although terrestrial broadcast television has migrated to digital standards such as ATSC and DVB-T, analog NTSC has experienced a major resurgence in First Person View (FPV) drone systems. Because digital video compression introduces critical latency that hampers high-speed drone navigation, FPV pilots rely heavily on instantaneous analog RF links. Seeber breaks down the structural components of an NTSC frame, explaining horizontal and vertical blanking intervals, sync pulses, color subcarrier phase modulation, and the "back porch." He walks through an interactive GNU Radio flowgraph that captures live 5.8 GHz RF downconverted video streams, de-interlaces frames, and displays raster video in real time.

### FMCW Radar Signal Synthesis and Demodulation The presentation shifts to Frequency Modulated Continuous Wave (FMCW) radar systems, a versatile analog waveform common across high-frequency (HF) maritime radars, altimeters, and automotive proximity sensors. Seeber explains the physics of linear frequency chirps, where the time delay between transmitted and received reflected chirps produces a detectable beat frequency proportional to target distance. Using offline processing tools and real-time GNU Radio blocks, he demonstrates how to synthesize FMCW waveforms, sample return echoes, and compute Range-Doppler matrices to visualize moving physical objects.

### Aviation Satellite Decoding and Spot Jamming Experiments In the concluding portion of the session, Seeber highlights advanced SDR experimentation, showcasing an SDR demodulator engineered to intercept and decode downlink channels from the INMARSAT Aero aviation satellite service. He explains how ground stations and transoceanic aircraft exchange telemetry and dispatch communications over L-band satellite links. Finally, he analyzes the operational mechanics, spectral characteristics, and countermeasures associated with RF spot jamming against vulnerable communication frequencies.

(AI summary — Gemini 3.8 Flash)