Which of the following is NOT a common map projection?

The correct choice identifies a projection that is not widely recognized or utilized in cartography. The Robinson, Albers, and Lambert projections are well-established map projections, each serving particular purposes and applications in GIS.

The Robinson projection is known for its compromise between size and shape distortion, making it visually appealing for world maps. The Albers projection is an equal-area projection, ideal for representing areas accurately, which is particularly useful for themes where area comparison is critical, such as demographics, agriculture, or land-use planning. The Lambert projection, specifically the Lambert Conformal Conic projection, is favored for aeronautical charts and maps of regions that are more elongated east-west, as it preserves angles, making it beneficial for navigation.

The Heptagonal projection, on the other hand, does not have a recognized role or application in standard cartographic practices. It lacks the foundational theoretical support and usability associated with established projections, rendering it non-commonly employed in geographic representations. This distinction is essential for GIS professionals to understand, as choosing the right projection is vital for the accuracy and effectiveness of spatial analysis and mapping.