Module local 

Local Cartesian frames and vectors typed by frame and unit.

Near a point, positions and velocities are naturally expressed in a local Cartesian frame — NED, ENU, or the vessel’s forward-right-down. Mixing frames is the classic sign error; adding a velocity to a displacement the classic unit error.

Vector3<F, U> carries both frame F and unit U in its type: Vector3<Ned, Distance> and Vector3<Enu, Distance> cannot be added, nor Vector3<Ned, Distance> and Vector3<Ned, Speed>. The same approach as Direction<F>, in three dimensions:

use kinavis_kernel::local::{Enu, Ned, Vector3};
use kinavis_kernel::Distance;

let ned: Vector3<Ned, Distance> = Vector3::new(Distance::ZERO, Distance::ZERO, Distance::ZERO);
let enu: Vector3<Enu, Distance> = Vector3::new(Distance::ZERO, Distance::ZERO, Distance::ZERO);
let _ = ned + enu; // mismatched types: `Ned` is not `Enu`

A LocalFrame is a NED frame anchored at a point: it converts a GeodeticPoint to a NED displacement from its origin and back, via EcefPoint on a named Ellipsoid.

use kinavis_kernel::geodesy::{Ellipsoid, GeodeticPoint, Height};
use kinavis_kernel::local::LocalFrame;
use kinavis_kernel::{Distance, Position};

let origin = GeodeticPoint::new(
    "50°45.3'N 001°20.0'W".parse::<Position>()?,
    Height::above_ellipsoid(Distance::ZERO),
);
let frame = LocalFrame::at(origin, &Ellipsoid::WGS84)?;

// A point one minute of latitude north of the origin.
let north = GeodeticPoint::new(
    "50°46.3'N 001°20.0'W".parse::<Position>()?,
    Height::above_ellipsoid(Distance::ZERO),
);
let ned = frame.ned_of(north)?;
// A minute of latitude on the ellipsoid at 50°N is 1854 m, not the
// sphere's 1852.
assert!((ned.north().metres() - 1854.1).abs() < 0.5);
assert!(ned.east().metres().abs() < 1e-6);
// The Earth curves away under a straight line: the point is slightly
// below the origin's horizontal plane.
assert!(ned.down().metres() > 0.0 && ned.down().metres() < 0.3);

Structs

Body

Forward, right, down: the vessel body frame.

Enu

East, north, up: surveying and mapping frame.

LocalFrame

NED frame anchored at a point.

Ned

North, east, down: the navigation frame.

Vector3

Three components of one quantity in one frame.

Traits

VectorFrame

Frame of a Vector3.

VectorUnit

Quantity carried by each Vector3 component.