A bank of order statistic filters applied to a set of antenna or transducer beams are used to detect and determine the line-of-bearing to the source of transient RF (or other, e.g., acoustic) signals. By applying order statistic filters to signals received by a set of antenna or transducer beams, this system sets a detection threshold that is unaffected by transient signals, thereby allowing the detection of these transient signals. Knowing which antenna beam the transient signals are located within allows the determination of a line of bearing to the source of the transient signals.