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How to create an online map with a non-Mercator Projection: Part 1

Sep

21

2009

Previous articles in this series, discussed different coordinate systems and map projections available, and why different systems suit different applications (Part 1, 2). This was followed by a look at geostatistical and thematic maps where data areas and data densities are important (Part 1, 2, 3). Virtually all online map applications use the Mercator projection. ...

Choosing a Projection, Part 3: Pseudo-Cylindrical Projections

Sep

16

2009

After looking at the need for global equal area projections and a number of different possible projections, we shall now look at the pseudo-cylindrical options. There are a lot more of these, so we cover them in an article of their own. Pseudo-cylindrical projections are similar to cylindrical projections, but the central meridian is the ...

Choosing a Projection, Part 2: Pseudo-Conic, Azimuthal, and Cylindrical Projections

Sep

15

2009

In the first part of this article, I argued against the use of Mercator and Equirectangular projections for web maps showing global data distributions and areas. Instead, an equal area projection is more appropriate because it preserves relative areas and data densities. In the final two parts, I shall look at some possible equal area ...

Choosing a Map Projection: Part 1

Sep

14

2009

Previously in this series (1, 2), we discussed the different map projections and coordinate systems that can be used for map generation. We also looked at the reasons for the many different projections, and some of the reasons why we might wish to choose a different projection. In this article, I shall make the case ...

Map Projections and Coordinate Systems: Part 2

Sep

9

2009

In the second part of this article, I shall look at map datums and coordinate systems. In the first half, published on Monday, I looked at different projection systems. As we saw in the first part, the map projection converts the curved surface of the Earth into a flat map. The datum is the model ...

Map Projections and Coordinate Systems: Part 1

Sep

7

2009

This two part article is intended as an introduction to map projections and coordinate systems. The second part of the article will be published on Wednesday. They start a new series of articles which I shall be publishing over the next few weeks. I shall look at different projections and coordinate systems, the inadequacies of ...