1. A method for determining calibration constants for calibrating a receive only phased array antenna comprising the steps of: providing a pair of transmit signals with unknown polarization; identifying known parameters including a location ({right arrow over (x)} n ) of an antenna element (n) of said phased array antenna, an orientation Δ{right arrow over (x)} n of said antenna element (n) polarization of element (n) relative to the orientation of element (n), and a location of a transmitter {right arrow over (x)} 1 ; identifying unknown parameters including weights (w n ) of the elements (n), and vertical magnitude (E v ) and horizontal magnitude (E H ) of each of said transmit signals; determining a receive signal at each of said antenna elements based on said transmit signals; defining six simultaneous equations with seven unknowns using one antenna element as a standard (p), a second antenna element (m, where m≠p) and a third antenna element (n, where n≠p and n≠m); solving said six simultaneous equations for weights for every possible set of three antenna elements to find a vector of calibration weight (w) for each antenna element; and averaging said calibration weights (w) for each antenna element.