What is meant by map calibration?

Question

What is meant by map calibration?

Answer 1

I'm not exactly sure what you mean, but possibly you are asking about field checking maps? The USGS will periodically send out survey teams to spot check a few locations in each quad to make sure they're accurate.

Answer 2

I think you mean referencing a map to a known grid, such as georeferencing a map to the UTM grid.  That would be a common requirement when using GIS, as indicated by a previous answer.

Answer 3

A Geographic Information System (GIS) is a computer program for storing, retrieving, analysing, and displaying cartographic data.

Answer 4

Could you be refering to magnetic declination? That's the difference between magnetic north and true north. A map, such as a USGS quad, will have a symbol on one corner indicating the degrees to adjust a compass to compensate. That angle varies depending on your specific latitude or how close you are to the North Pole.