mthh / flat-projection-rs

Fast geodesic distance approximations via flat surface projection

flat-projection

Fast geodesic distance approximations via flat surface projection

The FlatProjection struct can by used to project geographical coordinates from WGS84 into a cartesian coordinate system. In the projected form approximated distance and bearing calculations can be performed much faster than on a sphere. The precision of these calculations is very precise for distances up to about 500 km.

Usage

extern crate flat_projection;

use flat_projection::FlatProjection;

fn main() {
    let (lon1, lat1) = (6.186389, 50.823194);
    let (lon2, lat2) = (6.953333, 51.301389);

    let proj = FlatProjection::new(51.05);

    let p1 = proj.project(lon1, lat1);
    let p2 = proj.project(lon2, lat2);

    let distance = p1.distance(&p2);
    // -> 75.648 km
}

Benchmark

$ cargo bench

flat                    time:   [329.01 ps 331.10 ps 333.29 ps]
haversine               time:   [12.244 ns 12.338 ns 12.437 ns]
vincenty                time:   [262.92 ns 266.14 ns 270.01 ns]

According to these results the flat surface approximation is about 37x faster than the Haversine formula.

Related

• cheap-ruler – Similar calculations in JavaScripts
• cheap-ruler-cpp – C++ port of cheap-ruler

License

This project is released under the MIT license.