224 lines
7.7 KiB
Markdown
224 lines
7.7 KiB
Markdown
# SatMaster — F4BPO Satellite Tracker
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Amateur satellite tracking application with Doppler correction for FlexRadio 8600 and rotor control via PstRotator.
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**Stack:** Go + Wails v2 + Svelte
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**Platform:** Windows (primary), Linux/macOS (compilable)
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---
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## Features
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- 🗺️ **World map** — real-time satellite positions on NASA GIBS Blue Marble, footprint + groundtrack overlay, satellite SVG icon for tracked sat
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- 📡 **Polar plot** — az/el pass track with AOS/LOS markers, current position animation
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- 🕐 **Pass prediction** — 24h upcoming passes, Max El, duration, quality rating, single sat or full watchlist view
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- 📻 **Doppler correction** — automatic TX/RX frequency correction via FlexRadio 8600 TCP API, configurable RX/TX slices
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- 🔄 **Rotor control** — Az/El or Az-only commands to PstRotator via UDP XML protocol
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- 🛰️ **TLE management** — parallel fetch from Celestrak + PE0SAT, merged with deduplication, local cache fallback
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- 🔊 **AOS voice alerts** — Windows TTS announcement at AOS for all watchlist satellites, configurable voice
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- 📋 **Satellite frequency database** — 40+ satellites with nominal frequencies, auto-applied on selection
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- 🔍 **Watchlist** — persistent satellite selection with alphabetical sorting and duplicate prevention
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---
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## Architecture
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```
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SatMaster/
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├── main.go # Wails entry point
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├── app.go # App struct, Wails bindings, position loop, tracking
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├── wails.json # Wails project config
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│
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├── backend/
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│ ├── tle/
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│ │ └── manager.go # Parallel TLE fetch (Celestrak + PE0SAT), merge, cache, parse
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│ │
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│ ├── propagator/
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│ │ └── engine.go # SGP4 propagation (akhenakh/sgp4), az/el, pass prediction
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│ │
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│ ├── doppler/
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│ │ └── calculator.go # Doppler shift computation (range rate → Hz correction)
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│ │
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│ ├── flexradio/
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│ │ └── client.go # FlexRadio SmartSDR TCP API (port 4992)
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│ │
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│ └── rotor/
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│ └── pstrotator.go # PstRotator UDP XML protocol (port 12000)
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│
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└── frontend/src/
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├── App.svelte # Root layout, Wails events, AOS voice alert engine
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├── stores/satstore.js # Svelte stores + localStorage persistence
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├── lib/
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│ ├── wails.js # Wails Go call bridge + dev stubs
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│ ├── utils.js # Formatting helpers (freq, az, el, range, etc.)
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│ ├── satdb.js # Satellite frequency database (40+ sats)
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│ └── maidenhead.js # Maidenhead locator ↔ lat/lon conversion
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└── components/
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├── StatusBar.svelte # Top bar: clock, sat data, Doppler, SOUND/DOPPLER/ROTATOR toggles
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├── SatSelector.svelte # Left sidebar: watchlist, frequencies, track toggles, sat info
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├── WorldMap.svelte # Leaflet map, sat markers, SVG icon, footprint, groundtrack
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├── PolarPlot.svelte # SVG polar az/el plot
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├── PassesPanel.svelte # Pass list + detail + embedded polar plot
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└── SettingsPanel.svelte # QTH, FlexRadio, PstRotator, slices, voice alerts, TLE
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```
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---
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## Prerequisites
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```bash
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# Go 1.21+
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# Node.js 18+
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# Wails v2
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go install github.com/wailsapp/wails/v2/cmd/wails@latest
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# Verify
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wails doctor
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```
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---
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## Setup & Build
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```bash
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# 1. Clone / copy project
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cd SatMaster
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# 2. Download Go dependencies
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go mod tidy
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# 3. Install frontend deps
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cd frontend && npm install && cd ..
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# 4. Development mode (hot reload)
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wails dev
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# 5. Production build (single .exe)
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wails build
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# → build/bin/SatMaster.exe
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```
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---
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## FlexRadio 8600 — Protocol Notes
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SatMaster uses the SmartSDR **TCP API** on port **4992**.
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Commands sent:
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```
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slice t 0 145.800000 # Set RX slice frequency (MHz)
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slice t 1 145.200000 # Set TX slice frequency (MHz)
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slice s 0 mode=FM # Set slice mode
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```
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- Connect: Settings → FlexRadio → enter IP → Connect
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- RX slice (downlink) defaults to Slice A (index 0), TX to Slice B (index 1)
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- Configurable in Settings → FlexRadio → Satellite Slices
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- Doppler correction fires every second during active tracking
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- Dead-band: 1 Hz — updates only sent when shift exceeds threshold
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- Track Freq/Mode button is disabled if satellite has no known frequencies
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---
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## PstRotator — Protocol Notes
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SatMaster sends **UDP XML** to PstRotator on port **12000** (default).
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```xml
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<PST><AZIMUTH>180</AZIMUTH></PST>
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<PST><AZIMUTH>180</AZIMUTH><ELEVATION>45</ELEVATION></PST>
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```
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- Configure in PstRotator: Setup → UDP Server → Port 12000
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- Az-only or Az+El mode configurable in Settings → PstRotator → Rotor Mode
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- Dead-band: 5° Az and El to prevent rotor hunting
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- Elevation clamped to [0°, 90°] — no negative elevation commands sent
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- `ResetDeadband()` called when Track Azimuth is enabled to force immediate move
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---
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## TLE Data
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- **Primary source:** `https://celestrak.org/NORAD/elements/gp.php?GROUP=amateur&FORMAT=tle`
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- **Secondary source:** `http://tle.pe0sat.nl/kepler/amateur.txt`
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- Both sources fetched **in parallel** and merged — Celestrak takes priority on duplicates, PE0SAT contributes satellites not present in Celestrak
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- **Cache:** `%LOCALAPPDATA%\SatMaster\satmaster_tle_cache.txt` (Windows)
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- **Bundled fallback:** ISS, AO-7, AO-27, SO-50, FO-29, RS-44 (always available offline)
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- TLE age shown in status bar; use Settings → TLE Data → Refresh TLE to force update
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---
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## Pass Prediction
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- Step: 10s (30s when satellite below -15° elevation)
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- AOS/LOS bisection precision: 1 second
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- Horizon: passes below configured Min El are filtered from the list
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- 24-hour prediction window
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- Passes panel: single satellite view or full watchlist view
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---
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## Doppler Formula
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```
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f_corrected_down = f_nominal × (1 - v_range / c)
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f_corrected_up = f_nominal / (1 - v_range / c)
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where:
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v_range = range rate in km/s (+ = receding, - = approaching)
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c = 299792.458 km/s
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```
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Range rate is computed by finite difference (2-second interval) on the SGP4 position.
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---
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## AOS Voice Alerts
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SatMaster announces AOS for all watchlist satellites using Windows TTS (Web Speech API).
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- Announcement format: *"AOS [satellite name] is rising. Pass will last for X minutes."*
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- Toggle: StatusBar → 🔊 SOUND ON/OFF
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- Voice selection: Settings → Voice Alerts → TTS Voice dropdown
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- Recommended voices: **Microsoft David** or **Microsoft Zira** (English)
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- To install English voices: Windows Settings → Time & Language → Speech → Add voices → English (United States)
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---
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## Keyboard Shortcuts
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| Key | Action |
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|-----|--------|
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| `M` | Switch to Map tab |
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| `P` | Switch to Passes tab |
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| `S` | Switch to Settings tab |
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---
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## Satellite Frequency Database
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Built-in frequency database (`frontend/src/lib/satdb.js`) covers 40+ satellites including:
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| Satellite | Type | Downlink | Uplink |
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|-----------|------|----------|--------|
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| ISS | FM | 437.800 MHz | 145.990 MHz |
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| SO-50 | FM | 436.795 MHz | 145.850 MHz |
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| AO-91 | FM | 145.960 MHz | 435.250 MHz |
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| RS-44 | Linear | 435.640 MHz | 145.965 MHz |
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| AO-73 | Linear | 145.960 MHz | 435.140 MHz |
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| FO-29 | Linear | 435.850 MHz | 145.950 MHz |
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| QO-100 | Linear | 10489.750 MHz | 2400.250 MHz |
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| TEVEL2-1…9 | FM | 436.400 MHz | 145.970 MHz |
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| … | … | … | … |
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Frequencies are auto-applied when a satellite is selected. Multiple frequency entries per satellite are supported (e.g. ISS has FM voice + APRS).
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---
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## Future Enhancements
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- [ ] Multiple satellite tracking (split-screen polar)
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- [ ] Audio squelch mute between passes
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- [ ] Log4OM integration for contact logging
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- [ ] Export pass schedule to CSV/PDF
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- [ ] Linux/macOS rotor backend |