Module geodesy 

Earth figure, points with height, Earth-centred Cartesian coordinates.

A Position is latitude and longitude only (the chart view used by the sailings). Adding height raises “above what?”, and adding a Cartesian frame raises “on which ellipsoid?”. Both are explicit here: a Height carries its VerticalDatum, a GeodeticPoint is a position with such a height, and an EcefPoint is reached only through a named Ellipsoid.

A Position is on WGS 84 by definition. A position from an older chart is on that chart’s Datum and may be hundreds of metres off; Datum::to_wgs84 and Datum::from_wgs84 make the shift explicit via a Helmert transformation.

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

let here: Position = "50°45.3'N 001°20.0'W".parse()?;
let point = GeodeticPoint::new(here, Height::above_ellipsoid(Distance::from_metres(48.0)?));

let ecef = EcefPoint::from_geodetic(point, &Ellipsoid::WGS84)?;
let back = ecef.to_geodetic(&Ellipsoid::WGS84)?;

assert!((back.position().latitude().degrees() - here.latitude().degrees()).abs() < 1e-9);
assert!((back.height().value().metres() - 48.0).abs() < 1e-3);

Structs

Datum

Horizontal geodetic datum: ellipsoid and its transformation to WGS 84.

EcefPoint

Earth-centred, Earth-fixed Cartesian point, metres.

Ellipsoid

Reference ellipsoid.

GeodeticPoint

Position with height.

Height

Height with its vertical datum.

Helmert

Seven-parameter Helmert transformation between geocentric frames: translation, small rotation, scale.

Enums

VerticalDatum

Vertical datum.