Implement HF radiofax decoding with custom Python DSP pipeline
(rtl_fm USB → Goertzel/Hilbert demodulation), 33-station database
with broadcast schedules, audio waveform scope, live image preview,
and decoded image gallery. Amber/gold UI theme for HF distinction.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Two root causes for the waterfall/monitor lockup when scrolling past the
2.4 MHz RTL-SDR span:
1. safe_terminate() sent SIGKILL but never called wait(), leaving a
zombie process that kept the USB device handle open. The subsequent
capture restart failed the USB probe and the monitor could not use
the shared IQ path, falling back to a process-based monitor that
stole the SDR from the waterfall.
2. When the frontend created a new WebSocket after a failure, the old
handler's finally block called _set_shared_capture_state(running=False)
which could race with the new handler's running=True, making the
shared monitor path unavailable. Added a generation counter so only
the owning handler can clear the shared state.
The slant correction was severely under-correcting because bwd=50 caused
the sync deviation measurements to saturate after only ~25 lines (for a
2-sample/line SDR clock drift). Lines 25-256 all reported deviation=-50,
pulling the linear regression slope toward zero.
Increase bwd and fwd to 800 samples each — sufficient to track cumulative
drift from up to ~±200 ppm SDR clock offset across the full 256-line image.
Also use a full-sync-length (432-sample) Goertzel window instead of 1/3
length, giving ~111 Hz frequency resolution to cleanly separate the 1200 Hz
sync tone from 1500 Hz pixel data. Search is stepped at 5 samples (~0.1 ms)
for efficiency, keeping the goertzel_batch batch size at ~320 windows/line.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Previous attempts to correct slant by altering R-channel placement and
buffer consumption caused cascading failures: a false positive in B pixel
data would misplace R, then the wrong consumed value misaligned the next
line's G, and the error compounded across all 256 lines.
New approach (safe by design):
- Sync search is measurement-only: never touches pos or consumed, so
a noisy or wrong measurement cannot corrupt the current or future lines.
- Per-line deviation (measured sync position minus expected) is recorded
in self._sync_deviations throughout the decode.
- get_image() fits a line through the deviations (linear regression) to
estimate the per-line SDR clock drift rate, then applies a horizontal
shear to the assembled PIL image: each row is shifted by
-round(row × drift_rate × width / channel_samples) pixels.
- Worst case (all measurements fail): no correction applied, image
quality identical to the pre-change baseline.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
The step-49 coarse scan introduced up to ±24 sample uncertainty in R
channel placement. When accumulated SDR clock drift pushed the actual
sync 35+ samples early in the search region, the step-49 windows could
land on the B-pixel tail and return position 0, misplacing R by ~50
samples (~16 pixel colour shift) — worse than no correction at all.
Replace with a vectorised goertzel_batch sliding-window scan at step=1
over a short window (sync_duration / 3 ≈ 3 ms), giving single-sample
accuracy. Use consumed=pos (instead of max(pos,line_samples)) when the
sync is found, so the next line starts at its correct separator and
per-line timing errors stop accumulating entirely.
Falls back to the fixed-offset path whenever the sync is not found
(e.g. noisy signal), preserving the pre-change baseline quality.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
The previous sync search used search_margin = line_samples/10 (~306
samples for Scottie2), reaching deep into B channel pixel data behind
pos and well past the expected sync end ahead of pos.
When _find_sync returned a position in the late portion of that wide
region, pos + R_channel_samples exceeded the buffer length. The
buffer-too-short guard in _decode_line then returned early without
consuming data or advancing the line counter, causing the stall guard
in feed() to permanently break the decode loop.
Fix: use a 50-sample backward margin (covers >130 ppm SDR drift) and
a forward margin capped to whatever the current buffer can safely
support for the R channel. A final candidate-position check before
committing pos ensures no overflow is possible.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Scottie modes place their horizontal sync pulse between the Blue and Red
channels. The decoder was using a fixed offset to skip over it, so any
SDR clock error accumulated line-by-line and produced a visible diagonal
slant in the decoded image.
Fix: search for the actual 1200 Hz sync pulse in a ±10% window around
the expected position before decoding the Red channel, then align to the
real pulse. This resets accumulated clock drift on every scanline, the
same way Martin and Robot modes already handle their front-of-line sync.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Fix wrong VIS codes for PD90 (96→99), PD120 (93→95), PD180 (95→97),
PD240 (113→96), and ScottieDX (55→76). This caused PD180 to be detected
as PD90 and PD120 to fail entirely.
Replace batch Goertzel pixel decoding with analytic signal (Hilbert
transform) FM demodulation. The Goertzel approach used 96-sample windows
with ~500 Hz resolution — wider than the 800 Hz pixel frequency range —
making accurate pixel decoding impossible for fast modes like Martin2
and Scottie2. The Hilbert method computes per-sample instantaneous
frequency, matching the approach used by QSSTV and other professional
SSTV decoders.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Tolerate intermittent ambiguous windows during leader detection (up to
3 consecutive misses), use energy-based break detection when tone
classification fails at leader-break boundary, and add single-bit VIS
error correction for parity-bit and data-bit corruption on noisy HF.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
VIS detection recognized these modes but ALL_MODES had no decoder specs,
causing silent decode failures on common HF frequencies like 14.230 MHz.
Also emit a user-visible SSE event when an unsupported VIS code is detected.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The previous fix (f29ae3d) introduced a regression: when VIS parity
check failed or the VIS code was unrecognized, the detector entered
DETECTED state permanently and never resumed scanning. Now it resets
to IDLE on validation failure and only enters DETECTED on success.
Also resets partial image progress counter between consecutive decodes
and adds SDR device claiming to general SSTV route to prevent conflicts.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
VISDetector._process_window() was calling self.reset() inside the
STOP_BIT handler, wiping self._buffer before feed() could advance
past the triggering window. All audio samples buffered after the
VIS STOP_BIT (the start of the first scan line) were silently
discarded, causing the image decoder to begin decoding mid-stream
with no alignment reference. The result was every scan line being
desynchronised from the first, producing the diagonal stripes and
scrambled colours seen in decoded images.
Fix: remove the premature reset() from _process_window(). The
STOP_BIT handler now sets state=DETECTED and returns the result.
A new remaining_buffer property exposes the post-VIS samples.
_decode_audio_stream() and decode_file() capture those samples
before calling reset(), then immediately feed them into the newly
created SSTVImageDecoder so decoding begins from sample 0 of
the first sync pulse.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Weather Satellite:
- Fix duplicate event listeners on mode re-entry via locationListenersAttached guard
- Add suspend() to stop countdown/SSE stream when switching away from the mode
- Call WeatherSat.suspend() in switchMode() when leaving weathersat
- Fix toggleScheduler() to take the checkbox element as source of truth,
preventing both checkboxes fighting each other
- Reset isRunning/UI state after auto-capture completes (scheduler path)
- Always re-select first pass and reset selectedPassIndex after loadPasses()
- Keep timeline cursor in sync inside selectPass()
- Add seconds to pass ID format to avoid collisions on concurrent passes
- Improve predict_passes() comment clarity; fix trajectory comment
ADS-B dashboard:
- Batch altitude-colour trail segments into runs of same-colour polylines,
reducing Leaflet layer count from O(trail length) to O(colour changes)
for significantly better rendering performance with many aircraft
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- Fix SatDump crash reported as "Capture complete" by collecting exit
status via process.wait() before checking returncode
- Fix PTY file descriptor double-close race between stop() and reader
thread by adding thread-safe _close_pty() helper with dedicated lock
- Fix image watcher missing final images by doing post-exit scans after
SatDump process ends, using threading.Event for fast wakeup
- Fix failed image copy permanently skipping file by only marking as
known after successful copy
- Fix frontend error handler not resetting isRunning, preventing new
captures after a crash
- Fix console auto-hide timer leak on rapid complete/error events
- Fix ground track and auto-scheduler ignoring shared ObserverLocation
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Extend cross-mode analytics to include ACARS/VDL2 message counts, APRS
stations, and Meshtastic messages. Refactor count helpers into reusable
_safe_len() and _safe_route_attr() utilities. Add health checks for
rtlamr, dmr, and meshtastic modes.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The analytics summary, health, and export were only reading from legacy
DataStores (app_module.wifi_networks, bt_devices) which the v2 WiFi and
Bluetooth scanners don't populate. Now checks v2 scanner singletons
first and falls back to legacy stores.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Adds a unified analytics mode under the Security nav group that aggregates
data across all signal modes. Includes emergency squawk alerting (7700/7600/7500),
vertical rate anomaly detection, ACARS/VDL2-to-ADS-B flight correlation,
geofence zones with enter/exit detection for aircraft/vessels/APRS stations,
temporal pattern detection, RSSI history tracking, Meshtastic topology mapping,
and JSON/CSV data export.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Check process exit code when SatDump terminates — non-zero exit now
emits an error status with the exit code instead of falsely reporting
a successful capture completion.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
gpsd sends multiple SKY messages per cycle — some contain only DOP
values with an empty satellites array. Previously this would overwrite
the satellite list, causing the sky view to flicker empty. Now DOP-only
SKY messages preserve the existing satellite list. Also adds a 5-second
polling fallback for satellite data since SSE can miss sky updates due
to queue contention.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
start_gpsd_daemon() acquires _gpsd_process_lock then calls
stop_gpsd_daemon() which tries to acquire the same non-reentrant Lock,
causing an immediate deadlock. Changed to RLock so the same thread can
re-enter the lock.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Bluetooth enhancements (service data inspector, appearance codes, MAC
cluster tracking, behavioral flags, IRK badges, distance estimation),
ACARS SoapySDR multi-backend support, dump1090 stale process cleanup,
GPS error state, and proximity radar/signal card UI improvements.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
New modes:
- BT Locate: SAR Bluetooth device location with GPS-tagged signal trail,
RSSI-based proximity bands, audio alerts, and IRK auto-extraction from
paired devices (macOS plist / Linux BlueZ)
- GPS: Real-time position tracking with live map, speed, heading, altitude,
satellite info, and track recording via gpsd
Bug fixes:
- Fix ABBA deadlock between session lock and aggregator lock in BT Locate
- Fix bleak scan lifecycle tracking in BluetoothScanner (is_scanning property
now cross-checks backend state)
- Fix map tile persistence when switching modes
- Use 15s max_age window for fresh detections in BT Locate poll loop
Documentation:
- Update README, FEATURES.md, USAGE.md, and GitHub Pages with new modes
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Strip ITU-R M.493 phasing symbols (120-126) after dot pattern sync before
decoding message content. Fix MMSI BCD digit trimming direction and correct
test symbol encodings for position and MMSI edge cases.
Satellites added via CelesTrak import or TLE paste are now stored in
SQLite and survive page reloads and app restarts. Adds CRUD API
endpoints and wires frontend sidebar + dashboard to use them.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Add .gitignore entry for data/subghz/captures/ to prevent large
IQ recording files from being committed.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Security: replace path traversal-vulnerable str().startswith() with
is_relative_to(), anchor path checks to app root, strip filesystem
paths from error responses, add decoder-level path validation.
Architecture: use safe_terminate/register_process for subprocess
lifecycle, replace custom SSE generator with sse_stream(), use
centralized validate_* functions, remove unused app.py declarations.
Bugs: add thread-safe singleton locks, protect _images list across
threads, move blocking process.wait() to async daemon thread, fix
timezone handling for tz-aware datetimes, use full path for image
deduplication, guard TLE auto-refresh during tests, validate
scheduler parameters to avoid 500 errors.
Docker: pin SatDump to v1.2.2 and slowrx to ca6d7012, document
INTERCEPT_IMAGE fallback pattern.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Resolve conflicts keeping local GSM tools in kill_all() process list
and weather satellite config settings while merging upstream changes
including GSM spy removal, DMR fixes, USB device probe, APRS crash
fix, and cross-module frequency routing.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
When an external process (or stale handle from a crash) holds an SDR
device, claim_sdr_device() registry check passes but rtl_fm fails with
usb_claim_interface error -6. This adds a quick rtl_test probe inside
claim_sdr_device() so all modes get a clear error message before the
decoder pipeline is launched.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Remove all GSM cellular intelligence features including tower scanning,
signal monitoring, rogue detection, crowd density analysis, and
OpenCellID integration across routes, templates, utils, tests, and
build configuration.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Remove logging and cleanup_all_processes() from signal handler to
prevent deadlocks when another thread holds the logging or process lock.
Process cleanup is handled by the atexit handler instead.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Parse tshark GSM field values with int(value, 0) instead of int(value)
to auto-detect hex 0x-prefixed output (e.g. 0x039e for TMSI/LAC/CID).
Without this, every tshark line with hex values fails to parse, causing
0 devices to be captured during monitoring.
Also add API Keys tab to Settings modal for configuring OpenCellID key
via the UI (in addition to env var), with status display and usage bar.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
- Cache lookup now requires non-NULL lat/lon — previously a row with
NULL coordinates counted as a cache hit, returning {lat: None, lon: None}
which the frontend silently ignored (tower in list but no map pin)
- API response handler validates lat/lon exist before caching, preventing
error responses (status 200 with error body) from poisoning the cache
- On geocoding worker start, delete any existing poisoned cache rows
- Geocoding worker now logs "API key not configured" vs "rate limit
reached" so the actual problem is visible in logs
- API error responses now log the response body for easier debugging