Open map List

Normal Aspect

In cartography, the normal aspect of a map projection refers to the standard orientation of a projection’s developable surface (plane, cylinder, or cone) relative to the Earth’s surface. It defines how the projection is aligned with the globe and affects distortion patterns.

Intermediate

Introduction

Key Characteristics of Normal Aspect:

  • It follows the natural alignment of the projection’s reference surface.
  • The least distortion occurs along standard lines (such as the equator or central meridian).
  • It is typically classified based on the projection type:

Normal Aspects for Different Projections:

  1. Cylindrical Projections (e.g., Mercator Projection)

    • Normal Aspect: The cylinder is tangent to the equator (equatorial aspect).
    • The meridians and parallels are straight lines, and the least distortion occurs near the equator.
       

  2. Conic Projections (e.g., Albers Equal-Area, Lambert Conformal Conic)

    • Normal Aspect: The cone is aligned with the poles and touches the Earth along a latitude line (standard parallel).
    • Used for mid-latitude regions.
       

  3. Azimuthal (Planar) Projections (e.g., Stereographic, Orthographic)

    • Normal Aspect: The projection surface is tangent to a pole (polar aspect).
    • Used for mapping polar regions.

Other Aspects in Cartography:

  • Transverse Aspect: The projection surface is rotated 90° (e.g., Transverse Mercator aligns with a meridian instead of the equator).
  • Oblique Aspect: The projection is centered at an angled location (neither equatorial nor polar).
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