a digital television receiver is provided with a sounder comprising a wideband transmitter and a plurality of wideband receivers having separately located receiving antennas , so that the sounder is , in effect , a bistatic radar system for any given channel , in order to characterize a significant nearby , indoor reflector . a microprocessor receives the timing information generated by the wideband transmitter impulses and the reflected impulse returns to each of the receiving antennas , and calculates a multipath model representing the three - dimensional location of a significant , nearby scatterer .