Abstract: Spatial bandwidth imaging of the interior spaces and elements of a structure by transmission of low frequency, continuous-wave, narrow band signal or signals through the structure, measurement of the electric and magnetic components of the received signal received by narrow band Doppler or focused synthetic aperture methods over a range of signal paths extending from the transmitter and through the structure, and imaging of the effects of the interior space on the electric and magnetic components of the received signal.

Abstract: Determining the direction of a direct arrival path between a receiver and a transmitter in a multipath environment by determining a transmitter heading relative to the receiver as proportional to a frequency offset of the direct path signal component relative to a multipath pedestal, an absolute velocity of the transmitter as proportional to a width of the multipath pedestal, a relative velocity between the transmitter and the receiver as proportional to a magnitude and a direction of doppler shift of the direct arrival component of the received signal relative to the doppler pedestal, and an amplitude of the multipath pedestal as proportional to a number and magnitude of scatterers in the multipath environment. The method is applied for continuous wave and modulated signals, for stationary and moving transmitters and for tracking and mapping transmitter paths.