| 摘要 |
PROBLEM TO BE SOLVED: To provide a distance measurement system that exhibits an excellent resolving power of an in-plane, and what's more, an excellent resolving power to a height or a refractive index distribution in an out-of-plane and exhibits an excellent resolving power of a distance.SOLUTION: Transmission antennas 11 and 12 mounted onto an aircraft 10 transmit transmission waves of Asin(2&pgr;(fc+fm)t) and Asin(2&pgr;(fc-fm)t) based on a carrier signal frequency fc and a modulation frequency fm to a measurement target G on the ground. The transmission waves are irradiated to the measurement object G with irradiation areas A and B almost overlapped with each other but slightly shifted by a center distance &Dgr;x. Reception antennas 13 and 14 are disposed on an extension of a part letting an almost center of overlapped irradiation areas A and B of the transmission waves be a boundary. When a sum signal or a difference signal of signals received by the reception antennas 13 and 14 is used to detect a phase shift, height information about irradiation areas A and B. When the difference signal is used, in contrast to the sum signal, only a part at which a phase difference occurs contributes to the phase difference and thus, the resolving power becomes high and sensitivity becomes extremely high. |
