1. 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 processing a received microwave signal thereby forming signal data; and a processor receiving the signal data and executing computer-readable instructions comprising (a) estimating, from the signal data, a first propagation time for a first microwave signal received at a first antenna, the first microwave signal reflected from a surface, wherein the first antenna is one of the plurality of antennas; (b) calculating a first distance between the surface and the first antenna using the estimated first propagation time; (c) defining a first circle centered at the first antenna, the first circle having a first radius equal to the calculated first distance; (d) estimating, from the signal data, a second propagation time for a second microwave signal received at a second antenna, the second microwave signal reflected from the surface, wherein the second antenna is one of the plurality of antennas and is adjacent the first antenna; (e) calculating a second distance between the surface and the second antenna using the estimated second propagation time; (f) defining a second circle centered at the second antenna, the second circle having a second radius equal to the calculated second distance; (g) defining 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 the direction of the surface; (h) saving the defined tangent point in a set of tangent points; (i) repeating steps (a)-(h) for the first antenna being each of the plurality of antennas; and (j) applying a curve fit to the set of tangent points thereby determining a location of the surface.