Abstract: A radar system uses a rotating antenna array having rows that display dispersive properties while feeding multiple radiating elements. In some embodiments, the radiating elements are dual polarized. In at least one embodiment, beam spoiling may be used to generate an unfocused transmit beam that covers an entire elevation range of interest. Digital beam forming may be used during a receive mode to achieve a stack of narrow-width receive beams in elevation. Frequency scanning may also be used to achieve stacked beams in azimuth.

Abstract: A radar system uses a rotating antenna array having rows that display dispersive properties while feeding multiple radiating elements. In some embodiments, the radiating elements are dual polarized. In at least one embodiment, beam spoiling may be used to generate an unfocused transmit beam that covers an entire elevation range of interest. Digital beam forming may be used during a receive mode to achieve a stack of narrow-width receive beams in elevation. Frequency scanning may also be used to achieve stacked beams in azimuth.

Abstract: Methods and apparatus for combining radar signals of a two-dimensional primary radar covering a surveillance area and a passive adjunct radar to provide three-dimensional data for targets and weather. In exemplary embodiments, high beam and low beam data from the primary radar and elevation data from the adjunct radar can be used to mitigate interference from clutter, such as wind farms.

Abstract: A system and method for exchanging information between aircraft (210). Sensors on a first aircraft (210) provide data about the first aircraft's environment, including hazards such as turbulence, icing, lightning, or birds. The system transmits the data to receiving systems in other aircraft (210), which display the data, to warn the pilots flying the other aircraft of potential hazards. The pilot of the first aircraft may supplement the information with visual observations, about birds or unmanned aerial vehicles, for example. In one embodiment, the information is transmitted from aircraft to aircraft over a data link using ADS-B. In another embodiment, a first aircraft may transmit data to a second aircraft, which may relay, or re-transmit, the data to a third aircraft.

Abstract: A system and method for exchanging information between aircraft (210). Sensors on a first aircraft (210) provide data about the first aircraft's environment, including hazards such as turbulence, icing, lightning, or birds. The system transmits the data to receiving systems in other aircraft (210), which display the data, to warn the pilots flying the other aircraft of potential hazards. The pilot of the first aircraft may supplement the information with visual observations, about birds or unmanned aerial vehicles, for example. In one embodiment, the information is transmitted from aircraft to aircraft over a data link using ADS-B. In another embodiment, a first aircraft may transmit data to a second aircraft, which may relay, or re-transmit, the data to a third aircraft.

Abstract: Various embodiments are described herein for a moving target detector that processes input data to perform detection for a current range cell. The moving target detector includes a Doppler filter bank module for processing the input data to provide several Doppler outputs for the current range cell, a no-land-clutter path for processing several input data sets related to the several Doppler outputs to provide detection data by performing peak selection on each of the several input data sets and performing detection on the results of the peak selection, a land-clutter path for processing the several input data sets to provide detection data by performing Constant False Ala?n Rate (CFAR) detection on each of the several input data sets and merging the detection results; and a switching logic module for selecting one of the land-clutter path and the no-land-clutter path based on clutter information.

Abstract: Various embodiments are described herein for a moving target detector that processes input data to perform detection for a current range cell. The moving target detector includes a Doppler filter bank module for processing the input data to provide several Doppler outputs for the current range cell, a no-land-clutter path for processing several input data sets related to the several Doppler outputs to provide detection data by performing peak selection on each of the several input data sets and performing detection on the results of the peak selection, a land-clutter path for processing the several input data sets to provide detection data by performing Constant False Ala?n Rate (CFAR) detection on each of the several input data sets and merging the detection results; and a switching logic module for selecting one of the land-clutter path and the no-land-clutter path based on clutter information.

Abstract: A method and apparatus for estimating elevation angle when using a broad search beam such as a cosecant-squared beam is provided. The range of a target detected during a search with a broad beam covering a broad angular search area is determined. Based on the determined range, consecutive beams are transmitted at increasing search elevation angles in the broad angular search area. Echo signals of the consecutive beams are used to determine an elevation angle estimate for the target.

Abstract: A mechanism for combining signals of multiple radars to achieve increased range, radar sensitivity and angle accuracy is provided. A first signal beam is radiated from an antenna of a first radar in the direction of a target. A second signal beam is radiated from an antenna of a second radar in the direction of the same target. The echo signals from the first signal beam and the second signal beam are received at both radars. The echo signals received at the first radar are processed to produce first radar processed echo signals and the echoes signals received at the second radar are processed to produce second radar processed echo signals. The first and second radar processed echo signals are combined to form an aggregate value.

Abstract: A method and apparatus for estimating elevation angle when using a broad search beam such as a cosecant-squared beam is provided. The range of a target detected during a search with a broad beam covering a broad angular search area is determined. Based on the determined range, consecutive beams are transmitted at increasing search elevation angles in the broad angular search area. Echo signals of the consecutive beams are used to determine an elevation angle estimate for the target.

Abstract: A mechanism for combining signals of multiple radars to achieve increased range, radar sensitivity and angle accuracy is provided. A first signal beam is radiated from an antenna of a first radar in the direction of a target. A second signal beam is radiated from an antenna of a second radar in the direction of the same target. The echo signals from the first signal beam and the second signal beam are received at both radars. The echo signals received at the first radar are processed to produce first radar processed echo signals and the echoes signals received at the second radar are processed to produce second radar processed echo signals. The first and second radar processed echo signals are combined to form an aggregate value.

Abstract: An array antenna system for forming multiple independently steered beams is described. The antenna system includes series or parallel feed circuits and phase shifters which are not disclosed directly in the signal path between the feed circuits and antenna elements included in the array antenna system.

Abstract: An array antenna system for forming multiple independently steered beams is described. The antenna system includes series or parallel feed circuits and phase shifters which are not disclosed directly in the signal path between the feed circuits and antenna elements included in the array antenna system.

Abstract: A method of operating a pulse Doppler radar to increase the probability of detection of an airborne target is shown to consist of transmitting interrogating pulses with a high pulse repetition frequency and processing received signals using any conventional pulse Doppler technique for echo signals having a Doppler shift frequency outside the spectrum of Doppler shift frequencies of clutter and using a DPCA technique at a submultiple of the pulse repetition frequency for echo signals having a Doppler shift frequency within the spectrum of Doppler shift frequencies of clutter.

Abstract: A beam forming apparatus is provided having a plurality of beam ports producing a corresponding plurality of differently directed beams, each one of such beams being associated with a corresponding one of the beam ports, one of such beams being directed at a desired signal source and at least one of the beams being directed at an interfering signal source. A processor is coupled to the beam ports, for combining signals at such beam ports into a composite signal with the ratio of the power of the desired signal component of such composite signal to the power of the interfering signal component of such composite signal being increased from the ratio of the power in such desired and interfering signal components at the one of the beam ports associated with the beam directed at the desired signal source. The beam forming apparatus directs one of the beams at a desired signal source and an additional beam at each one of a number of interfering signal sources.

Abstract: An optically fed lens array radar system is provided with an on boresight ed and a plurality of off boresight feeds. When looking far enough off boresight, one switches from the on boresight feed to the appropriate off boresight feed. The off boresight feeds simultaneously cover a large scan angle and achieve with the on boresight a large bandwidth over the largest scan angle of interest.