FBSAT59

🌐 日本語 | English

Modern successor to GPredict — Amateur satellite tracking software

FBSAT59 is a ground-up rewrite of GPredict — the beloved amateur radio satellite tracker by Alexandru Csete OZ9AEC — built on a modern Python stack.

What's improved

Feature	GPredict	FBSAT59
Platform	Desktop only	Desktop + browser access from phones/tablets on the same LAN
Radio control	Requires separate rigctld	Built-in Hamlib (700+ radios) — select your rig in the GUI
SDR support	None	HackRF / RTL-SDR via SoapySDR — spectrum, demodulation, IQ recording
Doppler correction	Frequency only	Frequency + mode + CTCSS/DCS tone set automatically
Dual-rig	Supported	Rig 1 + Rig 2 — SDR dongle can be assigned as a rig
Satellite frequency DB	SATNOGS only, text-file editing	SATNOGS auto-sync + add/edit entries from the GUI
TLE updates	Auto-update supported	Multi-source auto-update with quality scoring
Pass prediction	List view	Graphical pass chart + sky radar + footprint on world map
Rotator control	Separate rotctld	Built-in Hamlib rotator — select from GUI, no rotctld needed
Supported OS	Linux, Windows, macOS (GTK+)	Linux, Windows, macOS, Raspberry Pi

Key Features

Desktop UI (Qt6)

Dashboard — zoomed world map + radar + live status bar in one view
World map with satellite footprints, ground tracks, and dot-click selection
Radar (sky view) — north-up, AOS/LOS times, multi-satellite colour-coded
Pass chart — graphical elevation curve with quality colour coding (excellent/good/fair/low)
Group Pass Chart — multi-satellite pass overview with hover tooltips
Upcoming Passes — target or group search, calendar picker, CSV export
Radio Control — Doppler correction, mode/CTCSS auto-set, transponder list; CW toggle button (one-click CW-U/CW-L on USB/LSB transponders, reverts to original mode with a second click); frequency preset (DL/UL written to rig at transponder selection so frequencies are correct before pressing Connect)
SDR Control — real-time spectrum analyser, NFM/USB/LSB/CW demodulation, IQ recorder, passband tuning with transponder lock
Autotrack/Record — automatic sequential satellite tracking with scheduled timer (start/stop time), auto rig+rotator connect at AOS / disconnect at LOS, automatic SDR audio/IQ recording between AOS and LOS, and METEOR / HRPT auto-reception (starts SatDump at AOS, stops at LOS)
- Satellite picker with live text-search filter (type to narrow down the full satellite list)
AOS/LOS desktop notifications (Linux: notify-send / macOS: osascript / Windows: PowerShell)

METEOR / HRPT Weather Satellite Reception

Access via the METEOR / HRPT tab (opened from Radio Control when a matching transponder is selected, or manually from the menu).

Receives weather satellite imagery via SatDump running as a subprocess.

Satellite	Mode	Frequency	SDR required
METEOR-M N2-3	LRPT	137.9 MHz	RTL-SDR / HackRF
METEOR-M N2-4	LRPT	137.1 MHz	RTL-SDR / HackRF
METEOR-M N2-3	HRPT	1700.0 MHz	HackRF + dish + LNA
METEOR-M N2-4	HRPT	1700.0 MHz	HackRF + dish + LNA
NOAA 18	HRPT	1707.0 MHz	HackRF + dish + LNA
NOAA 19	HRPT	1698.0 MHz	HackRF + dish + LNA
Metop-B	HRPT	1701.3 MHz	HackRF + dish + LNA
Metop-C	HRPT	1701.3 MHz	HackRF + dish + LNA

[SDR Connect] reads your SDR settings from Rig Settings and connects automatically
[📋 Log] opens a floating log window showing SatDump stdout/stderr
Autotrack integration — enable "METEOR / HRPT Reception" in the Autotrack/Record dialog to start SatDump automatically at AOS and stop at LOS
- The satellite in your Autotrack list must match the satellite you want to receive (determines AOS/LOS timing)
- The transponder choice does not affect SatDump reception (SatDump uses its own fixed frequency)

Communications (Digital Modes)

Access via the Communications menu (between Radio and Autotrack/Record). Each mode opens as a closeable non-resident tab.

APRS — receive and decode AX.25/APRS packets via Direwolf (TCP KISS) with a Rig + sound card, or via the built-in Bell 202 AFSK demodulator when an SDR is connected. Send APRS messages and position beacons (PTT via CAT). Received position packets appear as cyan ▲ pins on the Dashboard map. Callsign, SSID, and via path are saved. ADIF export.
Telemetry — receive and decode AX.25 telemetry frames from amateur satellites. Two receive modes:
- Bell 202 AFSK — built-in 1200 baud demodulator (SDR) or Direwolf (rig + sound card). Satellite picker shows the 12 satellites with built-in binary format definitions (ISS, JO-97, RS-44, MO-122, etc.). Raw hex display for all others. SDR auto-connects on Start.
- gr-satellites — if gr-satellites is installed, forwards raw IQ from the SDR to a gr_satellites subprocess via UDP. Supports 330+ satellites. SDR auto-connects on Start.
- Selecting a satellite in either picker automatically syncs the main satellite list and switches Radio Control to the correct telemetry/beacon transponder frequency. CSV export.
SSTV / SSDV — receive SSTV images (Robot36, PD120, Martin, Scottie) and SSDV packets from amateur satellites (e.g. ISS 145.800 MHz PD120 or 437.550 MHz Robot36). Works with SDR audio or a rig sound card. Auto-opens when a transponder description contains "SSTV", "SSDV", or "IMAGING".
FT4 — encode and decode FT4 using the built-in ft8_lib (ctypes — no WSJT-X required). Transmit via Rig + PTT. Auto-opens for RS-44, JO-97, MO-122, and other FT4-active satellites. ADIF export.
Q65 — EME (Earth-Moon-Earth) weak-signal digital mode. Decode via libq65 (built from WSJT-X source; pre-built bundles available via Help → Q65 Library Installation). Encode and transmit in pure Python — no libq65 required for TX. QSO state machine (IDLE→CALLING→EXCHANGE→CONFIRM→LOGGED) with PTT via CAT and Doppler freeze during transmission. Submodes A–E, periods 15/30/60 s. ADIF export.
UDP log broadcast — optionally sends one ADIF record per logged QSO (FT4, Q65, confirmed APRS message exchanges) to a configurable host:port (default 127.0.0.1:2333) over UDP, compatible with lightweight log-relay tools such as wavelog-gate and JT-Linker (not the WSJT-X binary UDP protocol used by JTAlert/GridTracker). Enable and set the destination in File → General Settings → Logging — the host can be another machine on the LAN. APRS QSOs are logged with MODE=PKT and a nominal 599/599 signal report (APRS has no report exchange) for eQSL/LoTW compatibility.
Help → Direwolf Installation… — detect, install, or update Direwolf on all platforms
Help → gr-satellites… — detect gr-satellites installation and show install instructions (apt / brew / pip)

Mobile Browser UI

Access from any smartphone or tablet on your local network — no app install needed.

Tracking tab — satellite list with live EL/AZ/Range + radar
Antenna tab — large AZ/EL readout, pass progress bar, transponder cards, remote RIG connect/disconnect
Pass Prediction tab — upcoming passes per satellite
Group Pass tab — search and display passes for a group
Compass-linked radar on Android (auto-rotates with device orientation)

Radio / Rotator Control

Hamlib 4.7.1 built-in — no separate rigctld needed
NET Control mode (rigctld/rotctld compatible) for existing setups
Dual-rig: Rig 1 + Rig 2 independent control (e.g. IC-9700 + HackRF)
Inverted transponder support with passband tuning
Catch-up rotator tracking with configurable timeout resend

Data Management

SATNOGS transmitter DB auto-sync (daily)
Community frequency DB — FT4 calling frequencies and other conventions not in SATNOGS
TLE multi-source: CelesTrak Amateur/CubeSat/Weather/Earth-Obs/Science/Stations, SATNOGS TLE API, manual entry
TLE quality scoring: excellent (<6 h) / good (<24 h) / fair (<72 h) / poor
Provisional NORAD IDs (90000-series) auto-resolved to real IDs
Manual TLE and transponder entries — never overwritten by auto-sync
Custom Favourite groups (configurable names, up to N groups)

Auto Fetch Schedule

FBSAT59 fetches TLE and transponder data automatically in the background. Manual updates are not normally required. Use manual sync only when you need the very latest data immediately (e.g. right before a pass of a newly launched satellite).

Data	Interval
Space Stations (ISS, CSS…)	every 1 hour
Amateur Satellites	every 2 hours
CubeSats	every 4 hours
Weather Satellites	every 6 hours
Earth Observation / Science	every 12 hours
Provisional TLEs (NORAD ≥ 90000)	every 12 hours
Active TLE fallback (NORAD 10000–89999)	every 24 hours
AMSAT operational status	every 24 hours

SATNOGS transponder data is fetched automatically on first launch. After that, use Satellite → Sync SATNOGS to refresh manually if needed. A summary is also available in the app under Help → Auto Fetch Rules.

In-app Updaters

Help → Check for Updates — downloads and installs the latest release automatically
Help → Hamlib Update — upgrades the bundled Hamlib without reinstalling the app

Installation

Windows

Download FBSAT59-Setup.exe from the Releases page and run the installer.

macOS

Download FBSAT59.dmg from the Releases page, open it, and drag the app to Applications.

Linux (AppImage)

# Download and make executable
chmod +x FBSAT59-*.AppImage
./FBSAT59-*.AppImage

Linux (from source — Ubuntu/Debian)

# 1. System packages
sudo apt install python3.11 python3-pip libhamlib-dev python3-hamlib \
                 python3-soapysdr soapysdr-module-rtlsdr soapysdr-module-hackrf

# 2. Clone
git clone https://github.com/JF9SOM/fbsat59.git
cd fbsat59

# 3. Python virtual environment
python3.11 -m venv .venv
source .venv/bin/activate
pip install -e .

# 4. USB radio permissions (udev rule)
sudo cp scripts/99-fbsat59.rules /etc/udev/rules.d/
sudo udevadm control --reload-rules
sudo usermod -aG dialout $USER
# Log out and back in to apply group membership

# 5. Run
python -m src.main

SDR Quick Start

Connect your SDR device (HackRF One, RTL-SDR, etc.)
Open Settings → Rig Settings → SDR Settings
Click Enumerate to detect devices
Select your device, set sample rate and gain, assign to Rig 1 or Rig 2
Click Connect — the SDR Control tab becomes active
Select a satellite and transponder — mode is set automatically

SDR — Platform Support

Platform	SDR support
Windows	✅ RTL-SDR, HackRF One (ctypes direct — WinUSB driver via Zadig required)
Linux	✅ All SoapySDR-compatible devices (system package install)
macOS	✅ All SoapySDR-compatible devices (Homebrew install)

Windows — On Windows, SoapySDR is fundamentally incompatible with WinUSB drivers and cannot open devices reliably. RTL-SDR and HackRF bypass SoapySDR entirely and communicate directly with the device DLL (librtlsdr.dll / hackrf.dll) via ctypes. Both RTL-SDR and HackRF require a one-time WinUSB driver setup with Zadig. Airspy, Airspy HF+, and ADALM-Pluto are not supported on Windows.

⚠️ Windows Zadig setup (RTL-SDR and HackRF)

Plug in your device.

Download and run Zadig (free).

In Zadig: Options → List All Devices, select your device (RTL-SDR: Bulk-In, Interface 0 / HackRF: Hackrf One). Set driver to WinUSB → click Install Driver. Do NOT select libusbK — it causes device detection failures.

Restart FBSAT59.

See also Help → SDR Device Installation for step-by-step guidance.

Linux — install via apt:

sudo apt install python3-soapysdr soapysdr-module-rtlsdr soapysdr-module-hackrf \
                 soapysdr-module-airspy

macOS — install via Homebrew:

brew install soapysdr soapyrtlsdr soapyhackrf soapyairspy

Linux — install via apt:

sudo apt install python3-soapysdr soapysdr-module-rtlsdr soapysdr-module-hackrf \
                 soapysdr-module-airspy

macOS — install via Homebrew:

brew install soapysdr soapyrtlsdr soapyhackrf soapyairspy

Other SoapySDR-compatible devices (LimeSDR, etc.) may work on Linux/macOS if the corresponding module is installed, but are not bundled on Windows.

SDRplay (RSP1, RSP2, RSPdx, etc.) — Not bundled on any platform because SoapySDRPlay3 depends on the proprietary SDRplay API library, which cannot be redistributed.

To use an SDRplay device (all platforms):

Install the SDRplay API from sdrplay.com/downloads (Windows/macOS installer or Linux .run script)

Install SoapySDRPlay3:

Linux: sudo apt install soapysdr-module-sdrplay3

macOS: build from source or conda install -c conda-forge soapysdr-module-sdrplay3

Windows: build from github.com/pothosware/SoapySDRPlay3 or use conda

Restart this software — your device will be detected automatically via SoapySDR.

ADALM-Pluto (PlutoSDR) — Not bundled on any platform (Windows CI build was unstable; Linux/macOS users must install manually). Available on all platforms via package managers.

How PlutoSDR networking works: when connected via USB, PlutoSDR creates a virtual Ethernet adapter. No special driver (Zadig / WinUSB) is needed on any platform. The device is reachable at IP address 192.168.2.1.

To use ADALM-Pluto (all platforms):

Connect PlutoSDR via USB (the USB network adapter is installed automatically).

Install libiio:

Linux: sudo apt install libiio-dev

macOS: brew install libiio

Windows: installer from github.com/analogdevicesinc/libiio/releases

Install SoapyPlutoSDR:

Linux: sudo apt install soapysdr-module-plutosdr

macOS: brew install soapyplutosdr or conda install -c conda-forge soapysdr-module-plutosdr

Windows: conda install -c conda-forge soapysdr-module-plutosdr or build from github.com/pothosware/SoapyPlutoSDR

Restart this software — PlutoSDR will be detected automatically.

Architecture

fbsat59/
├── src/
│   ├── core/     # Satellite engine (Skyfield) — elevation, Doppler, pass prediction
│   ├── ui/       # PySide6 Qt6 desktop UI
│   ├── web/      # FastAPI + WebSocket (LAN browser access on port 8080)
│   ├── rig/      # Hamlib radio/rotator control + SdrRigAdapter
│   ├── sdr/      # SoapySDR backend — device, pipeline, demodulator, recorder
│   ├── comms/    # Digital communications — APRS, Direwolf, Bell 202 AFSK, AX.25, FT4, Q65
│   ├── data/     # TLE/SATNOGS sync, SQLite DB, manual entries
│   └── i18n/     # Internationalization (gettext-based)
├── locale/
│   ├── en/LC_MESSAGES/   # English strings
│   └── ja/LC_MESSAGES/   # Japanese strings
└── tests/

On startup:

Qt6 main window launches
FastAPI/uvicorn starts in a background thread (port 8080)
DataSyncManager fetches TLE and SATNOGS data if stale
Status bar shows the LAN URL and a QR-code button for mobile access

Development Setup

pip install -e ".[dev]"

# Format
ruff format src/ tests/

# Lint
ruff check src/ tests/

# Type check
mypy --strict src/

# Tests (run only test_rig.py locally — full suite may be slow on low-power hardware)
python -m pytest tests/test_rig.py -q

# Recompile translations after editing .po files
msgfmt locale/ja/LC_MESSAGES/fbsat59.po \
      -o locale/ja/LC_MESSAGES/fbsat59.mo

See CLAUDE.md for the full architecture reference used during development.

Hardware Verified

Device	Type	Windows	Linux/macOS	Notes
Yaesu FTX-1F	Transceiver	✓	✓	Hamlib 4.7.1 model 1051, NET Control, Doppler
Yaesu FT-991AM	Transceiver	✓	✓	Hamlib 4.7.1 model 1036, NET Control, Doppler
Icom IC-9100	Transceiver	—	✓	Hamlib 4.7.1 model 3068, NET+Direct, SAT mode, Doppler (v0.1.27)
Icom IC-9700	Transceiver	✓	✓	Hamlib 4.7.1 model 3081, NET+Direct, SAT mode, Doppler (v0.1.27)
Icom IC-705	Transceiver	—	✓	Hamlib 4.7.1 model 3085, NET+Direct, generic (non-satmode) rig, frequency/mode/split/CTCSS confirmed working via raw CAT/CI-V fallbacks for several Hamlib backend quirks (2026-07)
RTL-SDR	SDR	✓ (WinUSB/Zadig)*	✓	ctypes direct on Windows, SoapyRTLSDR on Linux/macOS
HackRF One	SDR	✓ (WinUSB/Zadig)*	✓	ctypes direct on Windows, SoapyHackRF on Linux/macOS
Airspy R2 / Mini	SDR	❌ not supported	✓	SoapyAirspy (Linux/macOS only)
Airspy HF+	SDR	❌ not supported	✓	SoapyAirspyHF (Linux/macOS only)
ADALM-Pluto	SDR	❌ not supported	✓	SoapyPlutoSDR (Linux/macOS only)
FTX-1F + RTL-SDR	Dual-rig	✓	✓	Passband Tune + Lock verified

* Windows: both RTL-SDR and HackRF require a one-time WinUSB driver install via Zadig. SoapySDR is incompatible with WinUSB on Windows; RTL-SDR and HackRF bypass it via ctypes.

Adding a New Language

Copy locale/en/LC_MESSAGES/fbsat59.po to locale/<lang>/LC_MESSAGES/fbsat59.po
Translate the msgstr lines
Compile: msgfmt locale/<lang>/LC_MESSAGES/fbsat59.po -o locale/<lang>/LC_MESSAGES/fbsat59.mo
The new language will appear automatically in the Settings dialog

Roadmap

Phase 2 — Planned

Digital Modes — Amateur Satellites (SDR)

~~HRPT / LRPT~~ — implemented (METEOR-M / NOAA 18-19 / Metop-B/C via SatDump, with Autotrack integration)
~~CW decode~~ — implemented (AI-based CRNN + CTC decoder via deepcw-engine ONNX model; one-click install via Help → CW Model Installation…; SDR or sound card input; auto-opens on CW/CW-R transponder selection)
~~gr-satellites deep integration~~ — implemented (330+ satellites via gr-satellites subprocess with UDP IQ forwarding, satellite picker, SDR auto-connect, and transponder auto-select in the Telemetry tab)

Operational Satellite Reception (SDR) — Planned

Receivable with HackRF / RTL-SDR + appropriate LNA/filter. Open-source decoders exist for all of these and will be integrated as SDR plugins.

System	Band	Content	OSS Decoder
Inmarsat-C (STD-C)	1.5 GHz L-band	Maritime Safety Info (MSI), EGC, LRIT	JAERO
Cospas-Sarsat L-band	1544.5 MHz	Search & rescue beacon positions (PLB/EPIRB/ELT)	gr-satellites
Iridium L-band ACARS	1616–1626.5 MHz	Aviation ACARS messages over Iridium	iridium-toolkit
Orbcomm	137–138 MHz VHF	IoT/M2M data messages, AIS supplemental	gr-orbcomm
QZSS (Michibiki) data broadcast	1278.75 MHz L6	High-precision MADOCA-PPP augmentation, disaster alerts	qzsl6tool

Each decoder will run as a subprocess with results displayed in a dedicated plugin panel inside the SDR Control tab. Offline re-analysis from saved IQ recordings is also planned.

UI / UX

Japanese UI — translation files are already prepared; full JP mode coming in Phase 2
Observation log — record, summarise, and export worked satellite passes
SDR Device Installation dialog — USB VID/PID scan, guided driver install for RTL-SDR / HackRF on all platforms

Hardware

Real-world Doppler tests with TS-2000, FT-817ND, etc. (IC-9100/IC-9700 confirmed in v0.1.27)
WSJT-X / JS8Call frequency & mode sync

Contributions and feedback are welcome — open a GitHub Issue or submit a pull request.

License

GPL-2.0-or-later (compatible with GPredict)

Acknowledgements

GPredict — Alexandru Csete OZ9AEC
Skyfield — Brandon Rhodes
Hamlib — Hamlib Development Team
SATNOGS — Libre Space Foundation
SoapySDR — Pothosware
Direwolf — WB2OSZ (John Langner) — AX.25 / APRS / KISS software TNC
ft8_lib — Kārlis Goba YL3JG — FT4/FT8 codec (C library, GPL-2.0)
pySSTV — Dominik Heidler DL2DH — SSTV encoder/decoder
gr-satellites — Daniel Estévez EA4GPZ — amateur satellite telemetry decoders
SatDump — the SatDump Contributors — weather satellite imagery decoder (METEOR LRPT/HRPT, NOAA HRPT, Metop HRPT). FBSAT59 launches SatDump as a subprocess; it is not bundled.
WSJT-X — Joe Taylor K1JT and the WSJT-X Development Group — The Q65 protocol, libq65 source code (lib/qra/q65/), and the GF(64) encoding algorithm implemented in src/comms/q65/encoder.py are derived from WSJT-X (GPL-2.0). FBSAT59 does not bundle WSJT-X; libq65 is compiled separately from the WSJT-X source tree.
deepcw-engine — e04 — CRNN + CTC model for AI-based CW (Morse code) decoding from audio spectrograms. FBSAT59 downloads the pre-trained model.onnx from GitHub and runs inference via onnxruntime; the model is not bundled.

Name		Name	Last commit message	Last commit date
Latest commit History 1,186 Commits
.github/workflows		.github/workflows
assets		assets
docs/icon-samples		docs/icon-samples
locale		locale
scripts		scripts
src		src
tests		tests
.gitignore		.gitignore
CLAUDE.md		CLAUDE.md
README.ja.md		README.ja.md
README.md		README.md
pyproject.toml		pyproject.toml

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FBSAT59

What's improved

Key Features

Desktop UI (Qt6)

METEOR / HRPT Weather Satellite Reception

Communications (Digital Modes)

Mobile Browser UI

Radio / Rotator Control

Data Management

Auto Fetch Schedule

In-app Updaters

Installation

Windows

macOS

Linux (AppImage)

Linux (from source — Ubuntu/Debian)

SDR Quick Start

SDR — Platform Support

Architecture

Development Setup

Hardware Verified

Adding a New Language

Roadmap

Phase 2 — Planned

Digital Modes — Amateur Satellites (SDR)

Operational Satellite Reception (SDR) — Planned

UI / UX

Hardware

License

Acknowledgements

About

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Repository files navigation

FBSAT59

What's improved

Key Features

Desktop UI (Qt6)

METEOR / HRPT Weather Satellite Reception

Communications (Digital Modes)

Mobile Browser UI

Radio / Rotator Control

Data Management

Auto Fetch Schedule

In-app Updaters

Installation

Windows

macOS

Linux (AppImage)

Linux (from source — Ubuntu/Debian)

SDR Quick Start

SDR — Platform Support

Architecture

Development Setup

Hardware Verified

Adding a New Language

Roadmap

Phase 2 — Planned

Digital Modes — Amateur Satellites (SDR)

Operational Satellite Reception (SDR) — Planned

UI / UX

Hardware

License

Acknowledgements

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