1. A method for facilitating detection of a threat, the method comprising: i) operating a transmitter to transmit signals in the direction of a plurality of cells to pan a scene corresponding to said plurality of cells, at least some cells corresponding to different ranges relative to the transmitter; ii) operating a detector to detect reflected signals during an analysis period received from said plurality of cells; and iii) determining a threat reference threshold for the analysis period as a function of the reflected signals detected during the analysis period, said step of determining a threat threshold including: measuring detected reflected signals corresponding to at least some of said plurality of said cells to generate a measured signal value for each particular one of said at least some cells; modifying the measured signal values corresponding to some particular ones of said at least some cells by a distance factor corresponding to the distance the particular one of the cells is from the transmitter to generate a modified measured signal value for each of said some particular ones of said cells; and generating the threat reference threshold as a function of at least some of the modified measured signal values.