Caliper Mapping and Transportation Glossary


What is an overlay?

An overlay is a procedure that estimates the attributes of one or more features by superimposing them over other features, and figuring out the extent to which they overlap. You use overlays to estimate the attributes of features in a map layer based on data in another map layer.

For example, you can use an overlay to calculate:

  • The total length of streets in a city
  • The population, average income, and/or number of competitors near a potential store location
  • The number of hospitals, trauma centers, and other medical resources around an earthquake fault

GIS Software for Estimating Overlays

Maptitude Mapping Software gives you all of the tools, maps, and data you need to analyze and understand how geography affects you and your business. Estimate attributes around point, line, or area features.

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What is an overlay/Overlay definition: Circular areas overlayed on top of Census tracts and resulting attribute estimates

Estimate the populations and other demographic characteristics of areas such as the circular rings in this map by overlaying then with the Census tract layer