projection.UTM

projection.UTM is the Universal Transverse Mercator (UTM) projection, located in Projection.UTM.ts. It extends projection.EPSG9807 (Transverse Mercator) and creates parameterized projection instances by UTM zone via the create factory. It is an object mixin, accessed at runtime as projection.UTM.

import { projection } from "maptalks";

// zone 1-60; south=true for the southern hemisphere (false northing 10000000)
const utm = projection.UTM.create({ zone: 50, south: false });

Properties / Static Methods

• code: string — projection code, 'utm'.
• aliases: string[] — alias list, [].
• create(params): projection — Static factory creating a projection instance for a UTM zone. Parameters:
  • zone — UTM zone number (1~60), required; throws if invalid.
  • south — Boolean, whether southern hemisphere; false northing is 10000000 for south, 0 for north.

create computes centralMeridian = (zone + 0.5) * 6 - 180, scaleFactor = 0.9996, falseEasting = 500000, and reuses projection.EPSG9807.create's Transverse Mercator projection.

Methods

• project(p, out?): Coordinate — Project lng/lat into UTM coordinates (meters).
• unproject(p, out?): Coordinate — Unproject UTM coordinates back to lng/lat.
• Additionally inherits projection / batch / sphere methods from projection.EPSG9807 / projection.Common.

Example

// Beijing (~116.4°E, 39.9°N) projected with zone 50
const proj = projection.UTM.create({ zone: 50, south: false });
const coord = proj.project([116.4, 39.9]);