Abstract: In a holographic radar having receivers (10) for amplifying, detecting, and A/D-converting the RF signals in all range bins received by antenna elements (1) and a digital beamformer (11) for performing digital operations on the outputs of these receivers to generate a number of beams equal to the number of antenna elements, three or four antenna arrays (D0 to D3), each array (2) being formed of a plurality of antenna elements (1), are oriented in different directions to provide 360.degree. coverage and switches (12) are provided to switch the connection between the antenna elements (1) and the receivers (10) according to pulse hit numbers and range bin numbers. Thus high-speed 360.degree. scan coverage can be attained with a small, inexpensive apparatus requiring as many receivers, memory elements and a digital beam former as needed for a single antenna array.

Abstract: A radar system for finding the location of a second flying object from a first flying object, comprises a nondirectional antenna for radiating a first radio wave from the first flying object, a second nondirectional antenna provided on the second flying object to receive the first radio wave and to radiate a second radio wave generated by modulating the received first radio wave and an array antenna provided on the first flying object to receive the second radio wave. The respective amplitudes of the signals given by the antenna elements of the array antenna are compared individually with a specified level and an operation for determining the direction of arrival of the second radio wave is executed using the signals given by all the antenna elements when either of the amplitudes of the signals given by the antenna elements is greater than the specified level.