Patent ID: 7647089

Claim:
A system for determining a two-dimensional cross section of a surface location that defines an interface between an object to detect and an antenna, the determination of the surface location for use in an imaging system, the system comprising: a plurality of antennas; a receiver coupled to the plurality of antennas, the receiver defining signal data from a signal received by at least one antenna of the plurality of antennas; and a processor operably coupled to the receiver to receive the defined signal data, the processor configured to execute computer-readable instructions configured to cause the system to (a) estimate, from the signal data, a first minimum propagation time for a first signal received at a first antenna, the first signal reflected from a surface, wherein the first antenna is one of the plurality of antennas; (b) calculate a first distance between the surface and the first antenna using the estimated first minimum propagation time; (c) define a first circle centered at the first antenna, the first circle having a first radius equal to the calculated first distance; (d) estimate, from the signal data, a second minimum propagation time for a second signal received at a second antenna, the second signal reflected from the surface, wherein the second antenna is one of the plurality of antennas and is adjacent a transmit location of the first antenna; (e) calculate a second distance between the surface and the second antenna using the estimated second minimum propagation time; (f) define a second circle centered at the second antenna, the second circle having a second radius equal to the calculated second distance; (g) define a tangent point, the tangent point located on the first circle and on a line tangent to both the first circle and the second circle and in a direction of radiation of the first antenna toward the surface; (h) save the defined tangent point in a set of tangent points; (i) repeat steps (a)-(h) for the first antenna being each of the plurality of antennas; and (j) determine a location of the surface by applying a curve fit to the set of tangent points.