Sofars

中文

sofars is a pure Rust implementation of the International Astronomical Union's (IAU) official Standards of Fundamental Astronomy (SOFA). It provides a comprehensive, efficient, and industry-standard set of astronomical calculation tools for high-precision time scale transformations, coordinate system conversions, and fundamental astronomical modeling.

Key Features

Standard Compliance: Strictly follows IAU 2000/2006 models, ensuring numerical consistency with the original SOFA C library.
Pure Rust: No C compiler required. Enjoy Rust's memory safety, concurrency, and performance.
Comprehensive Coverage:
- Time Scales (ts): Precise transformations between UTC, TAI, TT, TDB, TCG, TCB, and more.
- Precession, Nutation & Polar Motion (pnp): Full implementation of IAU precession and nutation series.
- Fundamental Astrometry (astro): Core algorithms for apparent star positions, refraction, etc.
- Coordinate Systems (coords): Conversions between geocentric, heliocentric, and spherical systems.
- Vector & Matrix Operations (vm): 3D vector and rotation matrix utilities optimized for astronomy.
- Calendars (cal): Transformations between Julian Dates and Gregorian calendar dates.

Installation

Add the following to your Cargo.toml:

[dependencies]
sofars = "0.5.0"

Quick Start

The following example shows how to calculate the Earth Rotation Angle (ERA) for a given Julian Date:

use sofars::consts::DJ00;
use sofars::ts::era00;

fn main() {
    // 2000 January 1, 12:00 (TT)
    let tt1 = DJ00;
    let tt2 = 0.5; 
    
    let era = era00(tt1, tt2);
    println!("Earth Rotation Angle: {} radians", era);
}

Documentation

For detailed API documentation and function lists, please visit docs.rs/sofars.

License & SOFA Terms of Use

This project is licensed under the MIT License.

Important Note: Since the core algorithms are derived from the IAU SOFA source code, any use of this project must also comply with the SOFA license terms.