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.
```rust 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
} ```
``` $ cargo bench
distance/flat time: [22.727 ns 22.955 ns 23.196 ns] distance/haversine time: [63.349 ns 64.046 ns 64.787 ns] distance/vincenty time: [358.10 ns 363.16 ns 369.46 ns] ```
According to these results the flat surface approximation is about 3x faster than the [Haversine] formula.
This project is released under the MIT license.