DEFINITION:  Spatial Resolution

While offering more detail, high resolution imagery, (i.e.:  data acquired with a small Ground Sample Distance (GSD)), are more expensive to acquire, process, store, and use than low resolution imagery acquired with a large GSD.

Image-based mapping projects typically have an optimum GSD that is based on a compromise between minimum imagery resolution and the geographic extent of the project.

Here are some basic factors to help determine an optimum GSD for such a project.

• Required mapping scale(s) of the final mapping product(s).
• Size and neighborhood context of the smallest feature to be located, characterized, or extracted from the imagery.
• Overall size or scope of project.

The table below shows suggested map scale to GSD equivalencies.

GeoVAR