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

distance/flat           time:   [322.21 ps 323.82 ps 326.41 ps]
distance/haversine      time:   [12.604 ns 12.831 ns 13.162 ns]
distance/vincenty       time:   [346.79 ns 348.00 ns 349.61 ns]

According to these results the flat surface approximation is about 40x 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.