System Architecture

RF Input Processing AI Inference Output ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ │ RTL-SDR │ │ 16kHz PCM │ ┌───→│ Audio │────────→│ Browser │ │ Blog V4 │────────→│ Pipeline │────┤ │ Router │ WAV │ <audio> │ │ (rtl_fm) │ FM/AM │ │ │ └──────────────┘ └──────────────┘ └──────────────┘ │ or │ │ │ │ │ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ │ ffmpeg │ └───→│ Whisper │────────→│ Socket.IO │ │ Web Stream │────────→│ resample │ │ Hailo-8L │ text │ Transcript │ │ (ffmpeg) │ HTTP │ │ │ NPU │ │ Feed │ └──────────────┘ └──────────────┘ └──────────────┘ └──────────────┘ InputSource Transcriber Flask App

Default: Single-dongle time-share Optional: Dual-dongle ┌──────────────┐ 60s listen 30s scan ┌──────────────┐ ┌──────────────┐ │ RTL-SDR │───→ rtl_fm ─────→ pause ─────→│ dump1090 │───→│ ADS-B │ │ (device 0) │←── resume ←───── stop ←──────│ 1090 MHz │ │ Correlator │ └──────────────┘ └──────────────┘ │ │ AdsbScanScheduler │ Callsign │ alternates rtl_fm ↔ dump1090 │ extraction │ on a single dongle │ + flight │ │ matching │ ┌──────────────┐ runs continuously │ │ │ RTL-SDR #2 │─── 1090 MHz ──→ dump1090 ──→ JSON ──────────────→│ │──→ Leaflet.js │ (device 1) │ (no scheduling needed) └──────────────┘ Map Panel └──────────────┘ ADSB_DUAL_DONGLE=true AdsbReceiver

Orbital Prediction Recording Decoding ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ │ Celestrak │ TLE │ AptScheduler│ trigger │ rtl_fm │ WAV │ noaa-apt │ │ TLE Feed │────────→│ PyEphem │────────→│ 137 MHz FM │────────→│ CLI decode │ │ │ │ pass predict│ │ 60k/11025Hz │ sox │ │ └──────────────┘ └──────────────┘ └──────────────┘ └──────────────┘ │ ┌──────────────┐ │ PNG │ InputSource │ enter_apt_mode() ▼ │ pauses VHF │ exclusive SDR access ┌──────────────┐ │ scanning │ for 15-minute pass │ Satellite │ └──────────────┘ │ Panel UI │ └──────────────┘

Schedule HF Reception Decoding ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ │ NMC / NOJ │ UTC │ WefaxSched │ trigger │ rtl_fm │ WAV │ fldigi │ │ broadcast │────────→│ time-of-day │────────→│ -D 2 USB │────────→│ --wefax-only│ │ timetable │ │ freq select │ │ HF direct │ sox │ via Xvfb │ └──────────────┘ └──────────────┘ │ sampling │ │ │ │ -1.9kHz ofs │ └──────────────┘ ┌──────────────┐ └──────────────┘ │ │ InputSource │ enter_wefax_mode() │ PNG │ pauses VHF │ APT pass has priority ┌──────────────┐ │ scanning │ │ WEFAX │ └──────────────┘ │ Panel UI │ └──────────────┘ Frequencies: NMC 4346/8682/12786/17151 kHz · NOJ 2054/4298/8459/12412 kHz Day: 8–12 MHz Night: 2–4 MHz IOC 576 · 1809px width · greyscale

Carrier Monitor Detection Analysis ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ ┌──────────────┐ │ Distant FM │ forward │ rtl_fm │ PCM │ Meteor │ event │ Meteor │ │ carrier │ scatter │ 143.050 MHz │────────→│ Detector │────────→│ Analyzer │ │ (below │─ ─ ─ ─→│ -g 40 │ │ │ │ │ │ horizon) │ meteor │ 11025 Hz │ │ 30s rolling │ │ shower │ └──────────────┘ trail └──────────────┘ │ baseline │ │ calendar │ 80-120km │ threshold │ │ 7 showers │ altitude │ dB detect │ │ rate stats │ │ │ │ │ ┌──────────────┐ Ionized plasma │ duration: │ │ Perseids │ │ Meteoroid │ column reflects │ 50ms – 30s │ │ Geminids │ │ 11–72 km/s │ radio waves │ │ │ Leonids ... │ └──────────────┘ │ U: <0.5s │ └──────────────┘ │ O: >0.5s │ │ ┌──────────────┐ └──────────────┘ ▼ │ RTL-SDR #2 │ METEOR_DUAL_DONGLE=true ┌──────────────┐ │ (device 1) │ 24/7 independent monitor │ Meteor │ │ or device 0 │ lowest SDR priority │ Panel UI │ └──────────────┘ │ rate chart │ └──────────────┘

Priority Mode Preempts 1 (highest) APT Satellite Pass Everything — orbital window is fixed 2 WEFAX Broadcast Voice, Meteor — scheduled HF window 3 Voice Monitoring Meteor — user-selected frequency 4 (lowest) Meteor Detection Nothing — runs in idle gaps Single-dongle: modes are mutually exclusive, higher priority preempts lower. Dual-dongle: meteor detection runs on device 1 independently.