초록 ▼

A radar system for a helicopter having a mast and a plurality of blades coupled to the mast by shaft portions of the blades includes a transmitter and a receiver respectively transmitting and receiving a pulsed radar beam through a feed horn, a generator for generating the radar beam energy for tran

A radar system for a helicopter having a mast and a plurality of blades coupled to the mast by shaft portions of the blades includes a transmitter and a receiver respectively transmitting and receiving a pulsed radar beam through a feed horn, a generator for generating the radar beam energy for transmission by the transmitter, a processor, a display, and a passive reflectarray deposited on the underside of at least one blade of the helicopter. The reflectarray is a preferably flat array of passive microstrip elements which can impart a phase to the radar beam. A typical microstrip element is a patch whose dimensions may be controlled, and the size of which determines the phase for the location within the array of that element. The reflectarray is provided with a pattern which is designed to scatter the radar beam in a desired shape and direction to produce uniform mapping of the terrain over which the helicopter travels. According to another embodiment, a passive reflectarray is provided to the underside of at least one blade, while another passive reflect is provided to the topside of at least one blade, thereby permit both terrain and sky mapping. The radar system of the invention provides a radar system utilizing a lightweight and inexpensive passive radar reflector for use on helicopters of all sizes, and achieves 360.degree. coverage.

대표청구항 ▼

[ What is claimed is:] [1.] A radar system for a helicopter for mapping a target location, said helicopter having a rotor and a plurality of rotorblades, each of the rotorblades having a shaft portion which is coupled to the rotor and a blade portion with a top side, a bottom side, a free end, and a

[ What is claimed is:] [1.] A radar system for a helicopter for mapping a target location, said helicopter having a rotor and a plurality of rotorblades, each of the rotorblades having a shaft portion which is coupled to the rotor and a blade portion with a top side, a bottom side, a free end, and a shaft end, said radar system comprising:a) a transmitter means for transmitting a radar beam;b) a receiver means for receiving a reflection of the radar energy from the target location;c) a reflectarray on the blade portion of at least one of the rotorblades at a location other than at the free end;d) directing means for directing the radar beam from said transmitter means toward said reflectarray and for directing the echo of the radar beam from said reflectarray to said receiving means;e) processing means coupled to said receiver means for processing data related to the energy reflection received by said receiver means;f) display means coupled to said processing means for displaying a radar map of the target location based on the data from the processing means,said reflectarray adapted to passively shape and reflect the radar beam toward the target location and to passively shape and reflect the energy reflection of the radar beam returning from the target location into the directing means.