초록 ▼

A spatially modulated Bessel beam radar system for enhancing the resolution with which a range and an azimuth of a plurality of closely spaced targets is determined. In a Bessel beam radar system, a Bessel beam is generated by sequential spatial modulation of the radar signal while maintaining a con

A spatially modulated Bessel beam radar system for enhancing the resolution with which a range and an azimuth of a plurality of closely spaced targets is determined. In a Bessel beam radar system, a Bessel beam is generated by sequential spatial modulation of the radar signal while maintaining a constant spatial polarization, and the return signal from one or more targets is processed to determine its Bessel function content. To spatially modulate the radar beam, the point at which the radar signal is transmitted is moved around a circular orbit. In a first embodiment of the spatially modulated Bessel beam radar system (80), a radar dome (86) mounted on the distal end of a mast (84) is pivoted around an orbit (90). The radar signal is transmitted in a predefined direction, along a Poynting vector that is generally aligned with the plane of the orbit. In a second embodiment (110), a plurality of parabolic antennas (116) are arranged in a spaced-apart circular array around a common center. The radar signal is sequentially spatially modulated as it is transmitted from each of the parabolic antennas in sequence around the circular array, and the Poynting vector of the spatially modulated Bessel beam radar signal is generally transverse to a plane in which the parabolic antennas are disposed. The signal reflected back from plural targets comprises a complex phase history. To determine a range and azimuth for each target, a controller/processor (180), processes this signal to develop closed form Bessel functions from which target azimuth and range are determined. Alternatively, target azimuth is determined from a convolution of the complex phase history using a dot product detector (202).

대표청구항 ▼

A radar system capable of resolving multiple targets within a radar beam width, comprising: (a) transmitter means for producing a radar signal at a desired wavelength; (b) antenna means, connected to the transmitter means, for radiating the radar signal as a radar beam along a Poynting vector, and f

A radar system capable of resolving multiple targets within a radar beam width, comprising: (a) transmitter means for producing a radar signal at a desired wavelength; (b) antenna means, connected to the transmitter means, for radiating the radar signal as a radar beam along a Poynting vector, and for receiving a reflected signal from each target; (c) modulation means for periodically varying a position from which the antenna means radiates the radar signal by a fractional wavelength of the radar signal in respect to two orthogonal axes while maintaining a constant spatial polarization for the radar signal, thereby spatially modulating the radar beam; and (d) a receiver that includes processor means, connected to receive and process the reflected signals from the antenna means, for developing a phase history of the reflected signals, and further operative to derive from the phase history a function that uniquely determines an angular position of each target about the antenna means.