Crate sgp4

Expand description

This crate implements the SGP4 algorithm for satellite propagation

It also provides methods to parse Two-Line Element Set (TLE) and Orbit Mean-Elements Message (OMM) data.

A UTF-8 transcript of the mathematical expressions that compose SGP4 can be found in the repository https://github.com/neuromorphicsystems/sgp4.

§Example

The following standalone program downloads the lastest Galileo OMMs from Celestrak and predicts the satellites’ positions and velocities after 12 h and 24 h.

fn main() -> anyhow::Result<()> {
    let response = ureq::get("https://celestrak.com/NORAD/elements/gp.php")
        .query("GROUP", "galileo")
        .query("FORMAT", "json")
        .call()?;
    let elements_vec: Vec<sgp4::Elements> = response.into_json()?;
    for elements in &elements_vec {
        println!("{}", elements.object_name.as_ref().unwrap());
        let constants = sgp4::Constants::from_elements(elements)?;
        for hours in &[12, 24] {
            println!("    t = {} min", hours * 60);
            let prediction = constants.propagate(sgp4::MinutesSinceEpoch((hours * 60) as f64))?;
            println!("        r = {:?} km", prediction.position);
            println!("        ṙ = {:?} km.s⁻¹", prediction.velocity);
        }
    }
    Ok(())
}

More examples can be found in the repository https://github.com/neuromorphicsystems/sgp4/tree/master/examples.

Re-exports§

pub use chrono;

Structs§

Constants: Propagator variables calculated from epoch quantities and used during propagation
DatetimeToMinutesSinceEpochError: Nanoseconds overflow while converting from datetime to minutes since epoch
Elements: General perturbations orbital data parsed from a TLE or OMM
Geopotential: Model of the Earth radius and gravitational field
MinutesSinceEpoch: Minutes ellapsed since the elements’ epoch
Orbit: The Brouwer orbital elements
OutOfRangeEpochEccentricity: The orbit used to generate epoch constants has an invalid eccentricity
Prediction: Predicted satellite position and velocity after SGP4 propagation
ResonanceState: Represents the state of the deep space resonnance integrator
TleError: Represents a TLE parse error

Enums§

Classification: A satellite’s elements classification
ElementsError: Errors returned when creating epoch contants from elements
Error: Represents a propagation error caused by orbital elements divergence
KozaiElementsError: Represents a propagation error caused by orbital elements divergence
MinutesSinceEpochToDatetimeError: Nanoseconds overflow while converting from minutes since epoch to datetime
TleErrorLine: Input line where a parse error was found
TleErrorWhat: TLE error type

Constants§

WGS72: The geopotential model used in the AFSPC implementation
WGS84: The geopotential model recommended by the IAU

Functions§

afspc_epoch_to_sidereal_time: Converts an epoch to sidereal time using the AFSPC expression
iau_epoch_to_sidereal_time: Converts an epoch to sidereal time using the IAU expression
julian_years_since_j2000: Returns the number of years since UTC 1 January 2000 12h00 (J2000)
julian_years_since_j2000_afspc_compatibility_mode: Returns the number of years since UTC 1 January 2000 12h00 (J2000) using the AFSPC expression
parse_2lesalloc: Parses a multi-line TL/2LE string into a list of Elements
parse_3lesalloc: Parses a multi-line TL/3LE string into a list of Elements