Patent attributes
A system for measuring the height of bin contents includes transmitters for transmitting pulses of wave energy towards the upper surface of the contents and receivers for receiving echoes of the pulses and producing corresponding signals. The transmitters and receivers are distributed aerially above the contents. The system also includes a processing apparatus, for using the received signals to map the upper surface, that includes correlators that correlate pulse waveforms with the signals, and a beamformer. In one embodiment, the beamformer computes, from the signals considered as corresponding to echoes, of pulses from fewer synthetic transmitters, received at a synthetic receiver array, respective directions of arrival of the signals. In another embodiment, the beamformer computes respective directions of transmission and arrival of the signals, and the processing apparatus also includes a processor that selects, according to the computed transmission and arrival directions, which signals to use for the mapping.