摘要:
The present invention relates to a device for detecting objects. The device comprises at least one microwave-frequency transmitter and one microwave-frequency receiver. The receiver makes a relative rotary movement about the transmitter, a signal being transmitted toward an individual for several positions of the receiver on the circle of relative rotation, the signals reflected by points of an object and received by the receiver at the positions being supplied to processing means in order to form a radar image. The receiver and the transmitter can be installed on a disk with a very low moment of inertia. The invention applies notably for the detection of weapons or explosives carried by persons.
摘要:
A rotating antenna synthetic aperture radar apparatus having a module in the processor circuit in which are stored image definition values for reducing image errors. The module acts upon process circuits to subdivide the distance range illuminated by the antenna into individual distance intervals and to determine the reference functions in these distance intervals.
摘要:
A pulsed Doppler radar mounted adjacent to the tip of a helicopter rotor blade for sensing obstacles in the helicopter path. The rotor tip velocity shifts the frequency of radar echos so that, through pulsed Doppler radar techniques, the echos from obstacles can be separated from clutter.
摘要:
A radar device includes: an aperture surface including element antennas and phase shifters; an antenna phase control unit for calculating phase amounts based on a beam orientation direction and a rotation angle of the aperture surface; an antenna driving control unit for setting a rotation angle to a rotation mechanism; a signal processing unit for detecting a target with the use of the radar receiver, setting at least one of the rotation angle of the aperture surface or the beam orientation direction in the antenna driving control unit and the antenna phase control unit, and calculating the level of competing cluttering with the use of an antenna pattern, to thereby determine propriety of the rotation angle; and a pattern calculating unit for calculating the antenna pattern from the rotation angle of the aperture surface and from the beam orientation direction.
摘要:
A blade mounted radar system comprises a wind turbine having a hub and blades extending therefrom; a radar antenna configured to transmit and/or receive a radio frequency (RF) signal; and a processor in electrical communication with the radar antenna and configured to generate the RF signal for transmission and/or to process the received RF signal. The radar antenna is affixed to one of the blades of the wind turbine such that relative motion is defined between the radar antenna and a target within a line of sight of the radar antenna. The problem of the ground based radar line of sight being obscured by the wind turbine is mitigated in this setup, as radar and turbine coexist in the same structure. Improved performance and additional capability are enabled by elevated installation and vertical SAR imaging capability. Doppler capabilities are extended using known motion of the antenna relative to stationary objects.
摘要:
A hovering helicopter has a radar transmitter/receiver for transmitting radar pulses for illuminating a target for SAR imaging, and rotor blades for generating lift. Radar reflectors are on the rotor blades. The radar reflectors are oriented to reflect the radar pulses from the transmitter to the target as the rotor blades rotate. The radar pulses reflected by the moving reflector from the transmitter are timed to generate the synthetic aperture image using radar returns from the target. The receiver also receives blade returns directly reflected from the moving reflectors attached to the lift rotor blades. The receiver analyzes the blade returns to extract motion details of the reflectors and uses the motion details for motion compensation of target returns for SAR imaging.
摘要:
A helicopter-borne radar system has a synthetic aperture with rotating antennae (ROSAR). The antennae for transmitting and receiving radar pulses are arranged at the end of each arm rotating with the rotor, and are connected with the radar system which has at least one transmitting module, one electronic module with a central control device and an image processor as well as a display. In order to align the imaging on the display of the radar system with an inertial axis of the helicopter, and to limit the influence of a change of the rotational rotor on the imaging, a signal generator arranged at the rotor of the helicopter generates signals indicative of rotating positions of the rotor. The latter signals are transmitted to an electronic module of the radar system, which marks the flank of an individual signal from the signal sequence for a rotation of the rotor. This flank of a signal is defined as a “basic position” and is counted. The invention permits azimuthally phase-accurate synchronization between the viewing angle of a helicopter-borne radar system and an inertial axis of the helicopter, as well as a defined alignment of the image on the video screen with respect to an inertial axis of the helicopter (and thus with respect to the flight direction of the helicopter). The viewing direction of the radar system (ROSAR) can be adjusted by means of an electric regulator wheel, so that the pilot can set a desired defined viewing direction of the radar image on the video screen.
摘要:
A ROSAR wire detection method is based upon ROSAR focusing of entire segments of wire. By generating a wire reference signal comprised of a sum of coherent reference signals, the basis for reliable wire detectability is provided.
摘要:
In a rotating antenna synthetic aperture radar, a method and apparatus for unfocussed signal processing for the correlation of the received signals by means of the reference functions. In unfocussed signal processing, only the main portion of the receiving signal S.sub.E is used, in which the phase shift is smaller than or equal to 90.degree. for the go-and return-path of the signal. A simplified window function is used as a reference function whose width also corresponds to the main portion of the received signal. Preferably, the in-phase and quadrature component (I.sub.r, Q.sub.r) of the window function r are selected to be identical.
摘要:
A blade mounted radar system comprises a wind turbine having a hub and blades extending therefrom; a radar antenna configured to transmit and/or receive a radio frequency (RF) signal; and a processor in electrical communication with the radar antenna and configured to generate the RF signal for transmission and/or to process the received RF signal. The radar antenna is affixed to one of the blades of the wind turbine such that relative motion is defined between the radar antenna and a target within a line of sight of the radar antenna. The problem of the ground based radar line of sight being obscured by the wind turbine is mitigated in this setup, as radar and turbine coexist in the same structure. Improved performance and additional capability are enabled by elevated installation and vertical SAR imaging capability. Doppler capabilities are extended using known motion of the antenna relative to stationary objects.