Equirectangular projection

As a planar map (French Plate carrée ), also Rektangularprojektion (English Rectangular projection ) is called in mathematical cartography an equidistant cylindrical projection in normal position.

She was, despite her advanced age little earlier in use, but is now one of the more important types of projection.

Basics

The meridians are mapped route faithful. The parallels are distorted to the contact as circles or cut. The poles are reproduced with the same length as the equator, the surface distortion increases toward the pole to go.

The basic shape of the planar map is created when latitude and longitude are used directly in Cartesian coordinates:

It involves the simplest of possible map network designs.

Equirectangular

The square planar map is one of the oldest map projections, the oldest record dates from Marinos of Tyre (c. 100 AD). This is an equidistant cylindrical projection in normal position with a Berührkreis at the equator. The equator itself is isometrically, equatorial regions are also shown as relative angle and equal area.

Main design principle is that at any point on the map, the distance of any two adjacent latitudes and longitudes is two adjacent identical. This results in the mid-latitudes to relatively strong distortions in east-west direction, while the meridians are shown as long as half the equator - which is correct in the assumption of the earth as a sphere. For the card in a north-south direction is isometrically. The distortion of the width increases towards the poles to the factor.

Rectangular Plate Carree

In this variant, the cylinder intersects the earth or the ellipsoid. The interface circuits are isometrically next to the meridian. This results in a rectangular card network in proportion. Although the latitude and longitude circles have constant distances, but in that ratio, that is true for the mean latitude of the map (cutting width ). The widths between the cut circles are shown in abbreviated form, extends outward toward the poles. The distortion is.

Use

Due to the distortions of this projection was rarely used in cadastral surveying; she found herself in the nautical charts in early. Presumably, the Portuguese astronomer and mathematician Pedro Nunes (1502-1578) the first dealt with the following in their distortions and their influence on navigation.

A special meaning you come but in the modern geographic information systems, because the geographic coordinates can be entered directly into the card or read from it. Uses it will be based on application, treat the world records or on satellite data, such as NASA World Wind or astronomy programs. Most famous äquirektangularer record is the Blue Marble: Cloudless Earth NASA. Applications such as Google Maps or OpenStreetMap, however, use the conformal Mercator projection.