OAT Tracker

Python tools for OpenAstroTracker mount control and satellite pass planning.

This project contains:

• oat-tracker.py: live tracking of satellites, planets, and stars via INDI
• find-passes.py: quick upcoming-pass finder using Celestrak TLE data

Features

• INDI mount control using EQUATORIAL_EOD_COORD
• Satellite tracking with continuous coordinate streaming
• Pre-position slew before satellite rise
• Observer location cache (~/.cache/oat-tracker/observer.json)
• TLE and star lookup caching
• Clear connection diagnostics (timeouts, device mismatch, hardware link state)

Requirements

• Python 3.10+
• An INDI server and mount driver (tested with indi_lx200_OpenAstroTech)
• Dependencies listed in requirements.txt

Install:

python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt

Quick Start

1) Track ISS through INDI

venv/bin/python oat-tracker.py \
  --lat <lat> --lon <lon> --elev <elev> \
  --host <host> --port 7624 \
  --device "LX200 OpenAstroTech" \
  --target iss

After first run, location is cached, so later runs can omit --lat/--lon/--elev.

2) Find upcoming passes

venv/bin/python find-passes.py --lat <lat> --lon <lon> --elev <elev> --min-alt 20

Main CLI Options (oat-tracker.py)

• --target: iss (default), a NORAD ID, a Celestrak name fragment, a planet, or a SIMBAD-resolvable star
• --host, --port, --device: INDI connection settings
• --connect-timeout: timeout (seconds) for INDI handshake/device stages
• --interval: update period in seconds (default satellite cadence: 0.3)
• --min-alt: do not command mount below this altitude
• --preposition-lookahead: search window for next rise when below threshold
• --preposition-alt: altitude used for pre-position slew
• --show-indi-stderr: show native INDI/PyIndi stderr output
• --verbose: debug logging

Driver Serial Settings (Pi)

For the OAT setup validated in this repo, these settings were working:

• Port: /dev/serial/by-id/usb-1a86_USB_Serial-if00-port0 (or /dev/ttyUSB0)
• Baud: 19200

Set through INDI tools:

indi_setprop -h localhost -p 7624 "LX200 OpenAstroTech.DEVICE_PORT.PORT=/dev/ttyUSB0"
indi_setprop -h localhost -p 7624 "LX200 OpenAstroTech.DEVICE_BAUD_RATE.19200=On"
indi_setprop -h localhost -p 7624 "LX200 OpenAstroTech.CONNECTION.CONNECT=On"
indi_setprop -h localhost -p 7624 "LX200 OpenAstroTech.CONFIG_PROCESS.CONFIG_SAVE=On"

Troubleshooting

Connect succeeds but script exits early

Run with:

venv/bin/python oat-tracker.py ... --show-indi-stderr

This reveals native driver errors hidden in quiet mode.

Device ... did not establish a hardware connection

Check:

• Mount power is on
• USB cable and port are correct
• Driver port and baud match firmware
• User is in dialout group on Indi server

Notes

• Cache files live under ~/.cache/oat-tracker/.