California is divided into 12 zones in the 1927 coordinate system and 13 zones in the 1983 system. Zone 7 in the 1927 system was eliminated and included in Zone 5 of the 1983 system. The maximum allowed discrepancy between grid and geodetic distances is generally no more than 1% in either direction within a zone of the California coordinate system.

1. How many zones in California Coordinate System of 1927 are there in California? 12. How
many zones in California Coordinate System of 1983 are there in California? 13. What is the
maximum discrepancy allowed between the difference of Grid and Geodetic distance in ratio? In
miles?
Solution
11. the state is divided into seven zones
12. the state is divided into six zones. Zone 7 of California Coordinate System 1927, which
encompasses Los Angeles County, is eliminated and the area is included in Zone 5 of California
Coordinate System 1983.
13. When using State Plane coordinates the scale factors, also known as the K factors, are ratios
that can be used as multipliers to convert ellipsoidal lengths, also known as geodetic distances, to
lengths on the map projection surface, also known as grid distances, and vice versa. In other
words, the geodetic length of a line, on the ellipsoid, multiplied by the appropriate scale factor
will give you the grid length of that line on the map. And the grid length multiplied by the
inverse of that same scale factor would bring you back to the geodetic length again.
A typical State Plane Coordinate zone is represented by a grid plane of projection cutting
through the ellipsoid of reference. Â Â There, a distance from one point to another is longer on
the ellipsoid than on the grid. This means that right in the middle of a SPCS zone the scale factor
is at its minimum. In the middle a typical minimum SPCS scale factor is not less than 0.9999,
though there are exceptions. Outside of the intersections the grid is above the ellipsoid where a
distance from one point to another is shorter on the ellipsoid than it is on the grid. There at the
edge of the zone a maximum typical SPCS scale factor is generally not more than 1.0001, but
again there are now exceptions.