Abstract: The invention relates to a method for radar mapping an area and a radar equipment for wideband exploration at frequencies below 300 MHz. A large number of frequencies, for instance 1000, are distributed over a frequency band between for instance 12.5 and 200 MHz, and approximately corresponding to terms in a geometrical series but being different harmonics to a certain fundamental frequency. This is accomplished by a synthesis generator coupled to a phase control device and the generated frequencies are each amplified in a separate amplifier, the outputs of which are guided in groups to a number of antennas, tuned to different frequency bands and fewer than the number of frequencies. The reception is carried out in a similar way from the antennas with pre-amplifiers and a mixer each and an A/D-converter and a registration device. The equipment is meant to use the principle of so called synthetic aperture radar (SAR).

Abstract: The invention relates to a method for radar mapping an area and a radar equipment for wideband exploration at frequencies below 300 MHz. A large number of frequencies, for instance 1000, are distributed over a frequency band between for instance 12.5 and 200 MHz, and approximately corresponding to terms in a geometrical series but being different harmonics to a certain fundamental frequency. This is accomplished by a synthesis generator (1) coupled to a phase control device (7) and the generated frequencies are each amplified in a separate amplifier (2), the outputs of which are guided in groups to a number of antennas, tuned to different frequency bands and fewer than the number of frequencies. The reception is carried out in a similar way from the antennas with pre-amplifiers and a mixer (3) each and an A/D-converter (4) and a registration device (5). The equipment is meant to use the principle of so called synthetic aperture (SAR).