State Plane Coordinate System State Plane Coordinate System The State Plane Coordinate System (SPS or SPCS) is a set of 124 geographic zones or coordinate systems designed for specific regions of the United States. Each state contains one or more state plane zones, the boundaries of which usually follow county lines. There are 110 zones in the contiguous US, with 10 more in Alaska, 5 in Hawaii, and one for Puerto Rico and US Virgin Islands. The system is widely used for geographic data by state and local governments. Its popularity is due to at least two factors. First, it uses a simple Cartesian
Ground plane plane. The ground plane doesn't have to be a continuous surface. In the "ground plane antenna" style whip antenna, the "plane" consists of several wires "λ"/4 long radiating from the base of a quarter-wave whip antenna. The radio waves from an antenna element that reflect off a ground plane appear to come from a mirror image of the antenna located on the other side of the ground plane. In a monopole antenna, the radiation pattern of the monopole plus the virtual "image antenna" make it appear as a two element center-fed dipole antenna. So a monopole mounted over an ideal