Usage of millimeter waves in an on-board radar for detection of objects at small depth in ground

The principle of construction of millimeter-wave radar for detection of objects at small depth in ground from a flying vehicle is offered. In millimeter wavelength range it is possible to generate a sounding signal of very short duration (1 ns or less), which ensures a necessary resolution of depth. Other advantages of millimeter wavelength range is, that it allows one to ensure a high directivity of an airborne antenna at the acceptable dimensions of an antenna and to decrease the square of the irradiated section of the Earth´s surface. It essentially diminishes temporal extent of passive background interference from the Earth´s surface and allows detection of underground objects at small depth in the ground. However in a given set of cases it is not enough, as the Earth´s surface is irradiated with side lobes of an airborne antenna, to lower which below -20 dB by known means is usually very difficult. Therefore selection of a weak echo signal returned from an underground object at small depth in ground out of intensive passive background interference of the Earth´s surface requires application of special hardware. The essence of signal processing and its technical realization is illustrated