Abstract: A sensor includes a transmit antenna, a receive antenna, circuitry, and a memory. The transmit antenna includes N transmit antenna elements each transmitting a transmit signal. The receive antenna includes M receive antenna elements each receiving N receive signals including reflection signals reflected by an organism. The circuitry extracts a second matrix corresponding to a predetermined frequency range from an N×M first matrix representing propagation characteristics between each transmit antenna element and each receive antenna element calculated from the receive signals. The circuitry estimates the position of the organism by using the second matrix, and calculates a radar cross-section value with respect to the organism, based on the estimated position and the positions of the transmit antenna and the receive antenna.

Abstract: A positioning sensor includes a transmission antenna transmitting a transmission signal, a plurality of reception antennae, each receiving a reception signals, a receiver observing the each of the plurality of reception signals in a predetermined period, a processor, and a memory, in which the processor calculates a plurality of complex transfer functions based on the each of the plurality of reception signals, records each of the plurality of complex transfer functions in the memory as being associated with each time point, extracts, among the plurality of complex transfer functions, a plurality of pairs of two complex transfer functions respectively corresponding to two time points in a predetermined interval, calculates a plurality of pieces of differential information, and estimates to a location of a moving body based on each of the plurality of pieces of differential information.