# How many map projections are there?

## How many map projections are there?

Three of these common types of map projections are cylindrical, conic, and azimuthal.

## What projected coordinate system should I use?

Web Mercator is a common projected coordinate system designed for web mapping applications. Most of Esri’s basemaps are tiled in Web Mercator, so they can have the greatest compatibility.

What is the difference between datum and projection?

A datum is simply a foundation and reference for spatial measurements. A system of coordinates is then used to describe those measurements relative to the datum, and a projection is the visual representation of those measurements on a different surface.

### How do you choose a map projection?

When you choose a projection, the first thing to consider is the purpose of your map. For general reference and atlas maps, you usually want to balance shape and area distortion. If your map has a specific purpose, you may need to preserve a certain spatial property—most commonly shape or area—to achieve that purpose.

### Which is the most accurate map projection?

AuthaGraph
AuthaGraph. This is hands-down the most accurate map projection in existence. In fact, AuthaGraph World Map is so proportionally perfect, it magically folds it into a three-dimensional globe. Japanese architect Hajime Narukawa invented this projection in 1999 by equally dividing a spherical surface into 96 triangles.

What are the four most common map projections?

Introduction

Projection Type Key virtues
Lambert Conformal Conic conic conformal
Mercator cylindrical conformal and true direction
Robinson pseudo-cylindrical all attributes are distorted to create a ‘more pleasant’ appearance
Transverse Mercator cylindrical conformal

## Is WGS 1984 projected or geographic?

For example, the “WGS84 projection” is a geographic one. A UTM projection is a projected one. Either of these will use only one datum. However, the data on the map could have come from multiple sources, all with unique projections and therefore datums.