## Recent Changes (May 2026):

### Server-Sent Events (SSE) Push Architecture
- **SSE broker implementation** — `sse_broker.py` provides a fan-out broker with per-client bounded queues and overflow-drop policy
- **Live receiver updates via SSE** — receiver configuration and telemetry now push to connected clients instead of being polled
- **AOI configuration pushed via SSE** — AOI mutations broadcast real-time updates to all connected clients
- **Incremental DOM patching** — receiver cards and AOI lists update without full-page refresh
- **Connection status indicator** — status bar shows live SSE connection state with visual pill
- **Heartbeat mechanism** — daemon thread sends periodic heartbeats to detect stale connections
- **History mode isolation** — SSE CZML refresh suppressed during timeline scrubbing to prevent snap-back

### UI Redesign
- **Complete frontend rewrite** — new design token CSS system, restructured layout, and rewritten JS/CSS for a modern look
- **Status bar** — Cesium toolbar integrated into a persistent status bar with pipeline stats (receiver count, intersection rate, cluster count)
- **Hamburger menu** — stays in status bar and morphs into X on toggle
- **New typography** — switched to Geist/Geist Mono fonts with ~15% larger type scale
- **Signal filters** — scroll wheel support on sliders, thicker slider tracks, settings persist across page refresh via localStorage
- **Renamed controls** — "Capture Receivers" is now "Enable Processing"; signal filters button changed from "Apply & Refresh" to "Refresh"

### Mobile Support
- **Responsive mobile layout** — full mobile UI with drawer navigation, bottom sheet, status strip, and responsive breakpoint at 768px
- **Mobile scrub bar** — touch-friendly LOB history scrub bar with orientation-aware layout (portrait/landscape), start/end time labels, and 44px touch targets
- **Mobile history mode** — scrub bar auto-shows/hides when entering/exiting history mode, reuses desktop load handler
- **Mobile filters** — labels match desktop, with XSS escaping and CRUD sync hooks
- **Base layer picker** — visible on mobile view with fixed blank thumbnail on initial load

### Bug Fixes
- **Transmitter data refreshes on map** after AOI/exclusion rule changes
- **Points and billboards clamped to ground** — prevents depth clipping issues
- **Silenced quirks mode warning** from CesiumJS InfoBox iframe
- **Timeline highlight color** now matches the accent color
- **Live map refresh restored** — data source remove/re-add cycle fixed

### Receiver Error Handling
- **Robust receiver error handling** — automatic backoff, auto-reactivation, and error status shown in WebUI (reverted from master to avoid conflicts, will land with UI redesign)

## Changes (April 2026):

### Map & UI
- **LOB history timeline** — replay historical LOB data using CesiumJS timeline/animation controls with flash and accumulate display modes, preset time ranges, and timeline highlights showing when LOBs were recorded
- **AOI circle drawing rewritten** — smooth real-time preview while dragging, circles persist correctly after saving
- **Fixed clicking on intersection points inside AOIs** — points are no longer hidden behind AOI polygons
- **LOB lines no longer disappear** when an individual receiver goes inactive; only that receiver's LOBs are affected
- **Confidence ellipses now display correct size and orientation** — fixed rotation and axis scaling errors

### Stability & Reliability
- **Fixed DBSCAN process deadlock** — clustering no longer hangs under load; fixed associated semaphore leak
- **Fixed multiprocessing crashes** — switched to forkserver mode, resolving fork-after-thread deprecation warnings and forkserver argument passing
- **Eliminated race conditions** in receiver data access and AOI data fetching (proper locking throughout)
- **Fixed DOA angle normalization** — bearings near 0°/360° boundary are now handled correctly in all cases
- **Clustering skipped gracefully** when auto-epsilon computes zero (e.g., insufficient data points)

### Performance
- **Gzip compression** — web server responses are now gzip-compressed, reducing bandwidth usage for CZML and other payloads
- **Auto-epsilon calculation is dramatically faster** — replaced O(n²) Python distance loops with scipy `cdist`
- **Cluster extraction optimized** with numpy boolean masks instead of Python loops
- **AOI data cached** — eliminated redundant SQLite connections on every intersection computation
- **Thread-safe queues** replace shared mutable state for inter-thread communication

### Security
- **Fixed XML External Entity (XXE) vulnerability** in receiver XML parsing

### Housekeeping
- Migrated CLI argument parsing from deprecated `optparse` to `argparse` (same options, same behavior)
- Added database indexes for query performance
- Replaced magic numbers with named constants
- Removed substantial amount of dead/commented-out code across Python and JS

## Changes (November 2025):
- Bug fixes
  - Fixed loading spinner staying visible when CZML data fails to load
  - Added error handler to loadTxCzml() to ensure spinner is always hidden
- Update to czml3 3.0.0
  - **Breaking Change**: Replaced `Preamble` class with `Packet(id="document", name="...", version=CZML_VERSION)`
  - **Breaking Change**: `Document()` now requires keyword argument `packets=` instead of positional list
  - **Breaking Change**: `dumps()` method no longer accepts `separators` argument
  - **Breaking Change**: Property validation now strict with Pydantic
    - Removed invalid `zIndex` property from Point and Billboard (not supported)
    - Changed `heightReference` from string to dict: `{"heightReference": "CLAMP_TO_GROUND"}`
    - Changed Polyline `positions` from `Position` to `PositionList`
    - Kept `zIndex` in Ellipse properties (valid for Ellipse)
  - Fixed incorrect use of `Material` class for polyline materials
  - Changed to use `PolylineMaterial` for polyline-specific materials (polylineOutline, polylineDash)
  - Updated all Document() calls to use `Document(packets=[...])` syntax
  - Updated all dumps() calls to remove separators argument
  - Removed unused `Material` import and `Preamble` import
  - Now imports `CZML_VERSION` and `PositionList` from czml3
  - Updated requirements to czml3 >= 1.0.0 (now maintained by Stoops-ML)
  - Note: czml3 v2.0+ uses Pydantic for all classes with strict validation
- Update to CesiumJS 1.135
  - Migrated from deprecated `imageryProvider` option to modern `baseLayer` API
  - Updated to use `ArcGisMapServerImageryProvider.fromUrl()` async pattern
  - Updated to use `ImageryLayer.fromProviderAsync()` for imagery layer initialization
  - Using official Cesium CDN for latest version (1.135)
- Power and Confidence range sliders have been updated to reflect data output by the KrakenSDR software.

## Previous Changes
- Update to CesiumJS 1.95
- Ellipse parameters are now automatically calculated. You can still adjust them
if you want, but the auto-calculation works exceptionally well.
- LOB Length is now determined by the distance to the furthest intersection from
the receiver.
- Fixed bug where map lags behind the receiver.
- Changed the way ellipse and clustering parameters are handled. This allows for
multi-user map interaction.
- Updated to Cesium 1.79
- The LOB for each receiver on the map changes color based on the power and
  confidence thresholds.
    - Green when both power and confidence are above their thresholds
    - Orange when just power is above it's threshold.
    - Red when power is below it's minimum threshold.
- Receivers on map update every 2.5 Seocnds.
    - To customize this change `refreshrate` at the top of `static/receiver_configurator.js`.
- Your old database files will not work directly with this latest commit. Several changes have been made
  to the database structure to accomodate new features.
- Now introducing Single Receiver Mode! This will give you functionality similar to, but better than
  the Kerberos SDR Android App. You can define multiple search areas, or even just define areas you
  know where the transmitter isn't located.
- The access token is now optional.
- Be on the lookout for documention and tutorials between Christmas and New Years.
- Behind the scenes, there have been several optimizations.
- Added option to invert (uninvert?) the DOA bearing. If you're using a KerberosSDR,
  keep this option checked.
- LOBs are drawn for each receiver. The orange lines extending from each receiver
  show the direction the signal is coming from. Currently the line is fixed to 40km
  draw distance.
- Receivers can be added from the WebUI
    - Click the + at the bottom of the receiver cards, enter the URL, click save.
    Click the refresh button to update the cards and map.
- A list of receiver URLs is now optional. Receivers are saved to the database.
    - Receivers are read from the database first. Duplicate receiver URLs are ignored.
- You can mark a receiver as mobile.
    - Click the edit icon for the applicable receiver, click the checkbox to mark
      it as mobile, then click save.
- You can now delete receivers from the list. This will remove it from the map
and database. No historical data is affected.
- You can now enable/disable LOB collection from individual receivers.
Click the power button to enable/disable.
    - Black is enabled, red is disabled.
- If you lose connectivity to a receiver, that particular receiver will be disabled.
  Click the power button to try to reconnect.
- ~~Map refreshes every 5 seconds. Change `refreshrate` at the top of `static/receiver_configurator.js` to change the refresh rate.~~