What are false easting and false northing in map projections?

• A. Added constants to all coordinates in a zone to ensure positive coordinates and avoid negative values.
• B. Measures of error due to instrument misalignment.
• C. Rotation parameters applied to align axes.
• D. An offset used to scale the projection.

Answer: (A)

In map projections, false easting and false northing are fixed offsets added to the projected coordinates to keep all grid values positive within a zone. This constant shift makes the grid numbers convenient to work with and avoids negative coordinates, which is especially useful for indexing and display. For example, a common system assigns a central meridian a false easting of 500,000 meters, so easting values stay positive across the zone. In the southern hemisphere, a large false northing (such as 10,000,000 meters) is added so northing values don’t become negative. These offsets are defined by the projection and do not represent measurement error, rotation, or scaling—they simply relocate the origin of the grid.