astroz 0.4.2

Python bindings for astroz - high-performance astrodynamics library

astroz Python Bindings

High-performance SGP4 satellite orbit propagation for Python, powered by Zig with SIMD acceleration.

Quick Start

from astroz import Tle, Sgp4
import numpy as np

# Parse TLE
tle = Tle("""1 25544U 98067A   24127.82853009  .00015698  00000+0  27310-3 0  9995
2 25544  51.6393 160.4574 0003580 140.6673 205.7250 15.50957674452123""")

# Single propagation
sgp4 = Sgp4(tle)
pos, vel = sgp4.propagate(30.0)  # 30 minutes after TLE epoch

# Batch propagation (fastest)
times = np.arange(0, 1440, 1.0, dtype=np.float64)  # 1 day, 1-min intervals
positions = np.empty((len(times), 3), dtype=np.float64)
velocities = np.empty((len(times), 3), dtype=np.float64)
sgp4.propagate_into(times, positions, velocities)

Performance

1.3-2.9x faster than python-sgp4:

Scenario	astroz	python-sgp4	Speedup
2 weeks (second intervals)	160 ms	464 ms	2.9x
1 month (minute intervals)	5.9 ms	16.1 ms	2.7x

API

Tle

tle = Tle(tle_string)
tle.satellite_number  # NORAD catalog number
tle.epoch            # Epoch (J2000 seconds)
tle.inclination      # Degrees
tle.eccentricity
tle.mean_motion      # Rev/day

Sgp4

sgp4 = Sgp4(tle, gravity_model=WGS84)  # WGS84 (default) or WGS72

# Single point
pos, vel = sgp4.propagate(tsince)  # tsince in minutes
# Returns ((x,y,z), (vx,vy,vz)) in km and km/s (TEME frame)

# Batch (fastest) - writes directly to pre-allocated arrays
sgp4.propagate_into(times, positions, velocities)

Building

Requires Zig and Python 3.10+.

zig build python-bindings \
  -Dpython-include=$(python -c "import sysconfig; print(sysconfig.get_path('include'))") \
  -Dpython-lib=python3.12 \
  -Dpython-lib-path=$(python -c "import sysconfig; print(sysconfig.get_config_var('LIBDIR'))") \
  -Doptimize=ReleaseFast

cp zig-out/bindings/python/astroz/lib_astroz.so bindings/python/astroz/_astroz.so
pip install -e bindings/python