The previous learning guide described the map projection process. This process can seem a little overwhelming -- there are so many projection characteristics to choose from. With three major projection forms, two different cases, an infinite number of possible aspects, different spheroids and different locations for light sources, its sometimes hard to know where to begin in selecting an appropriate projection for a mapping project.
Fortunately, over the years cartographers have developed a relatively small number of standard map projections that are very widely used. These standard projections have many established characteristics. Thus, when a spatial scientist talks of a Lambert's projection, he or she doesn't need to indicate the case, form, and so on -- most of that stuff is standardized as part of a the definition of a Lambert's projection.
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| A Robinson Projection | A Sinusoidal Interrupted Mollweide Projection
| A Polyconic Projection
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Before you get too excited about standard map projections, you need to know that they don't absolve you of all responsibility for choosing projection parameters. In fact, it would probably be more accurate to call them "standard projection families" rather than standard projections. While standard projections define most projection characteristics, they seldom define all such characteristics. Thus, there isn't just one Lambert's projection; there are many different Lambert's projections, each sharing a lot of common characteristics, but differing in others.
This learning guide will describe some of the major standard
projections in use today. Be aware that the list of projections
included here is by no means complete; there are literally
hundreds of others. However, the projections listed here are
the ones you are most likely to find in common usage.