Abstract: Systems and methods for allowing dual-mode radar operation. An exemplary transmission system includes a hybrid coupler that receives a signal produced by a synthesizer and couples the received signal to two output ports. A pulse transmitter receives a pulse transmit-activate signal from a controller, receives an input signal from the hybrid coupler and, if the activate signal has been received, amplifies the received signal based on a predefined desired pulse output transmission setting. A frequency-modulation continuous-wave (FMCW) transmitter receives an FMCW transmit-activate signal from the controller, receives an input signal from the hybrid coupler and, if the activate signal has been received, amplifies the received input signal based on a predefined desired FMCW output transmission setting. An isolator protects the pulse transmitter during FMCW operation and also the FMCW transmitter from receiving power reflected off of pulse transmitter components.

Abstract: One embodiment is directed to a method for operating a radar altimeter. The method includes transmitting a radar signal at a first frequency, ramping the frequency of the radar signal from the first frequency to a second frequency, and transmitting the radar signal at the second frequency. The reflections can be processed by determining an approximate distance to a target based reflections of the frequency ramp and the approximate distance can be refined based on a phase difference between a reflection of the radar signal transmitted at the first frequency and a reflection of the radar signal transmitted at the second frequency.

Abstract: One embodiment is directed towards a FMCW radar having a single antenna. The radar includes a transmit path having a voltage controlled oscillator controlled by a phase-locked loop, and the phase-locked loop includes a fractional-n synthesizer configured to implement a FMCW ramp waveform that ramps from a starting frequency to an ending frequency and upon reaching the ending frequency returns to the starting frequency to ramp again. The radar also includes a delay path coupled between a coupler on the transmit path and a mixer in a receive path. The delay path is configured to delay a local oscillator reference signal from the transmit path such that the propagation time of the local oscillator reference signal from the coupler to the mixer through the delay path is between the propagation time of signal reflected off the antenna and the propagation time of a leakage signal through a circulator.

Abstract: A radar system including a plurality of mini radars may be conformable to a structure that it is attached or built into. A radar system includes a clock, a plurality of frequency modulated/continuous wave (FM/CW) radar units in signal communication with the clock and a processor in signal communication with the plurality of FM/CW radar units. Each of the plurality of FM/CW radar units includes a row of antenna elements.

Abstract: Systems and methods for automatically determining a noise threshold are provided. In one implementation, a system comprises: an antenna configured to gather data about a surrounding environment; a processing unit configured to remove samples representing target data from the gathered data; to estimate the noise floor from the gathered data with the removed target data; and to determine a noise threshold from the estimated noise floor; and a memory device configured to store the estimated noise floor.

Abstract: Systems and methods for providing passive bird-strike avoidance. A passive L-band receiver system is located on an aircraft. The system includes a processor and an antenna having an array of four or more elements. The antenna configured to receive L-band signals. The processor receives the L-band signals from the antenna, determines if the received L-band signals indicate a target, determines distance, direction of travel and speed of any determined targets, determines if the target is a flock of birds based on the determined speed and determines if a hazard condition exists based on the distance, direction and speed.

Abstract: Systems and methods for allowing dual-mode radar operation. An exemplary transmission system includes a hybrid coupler that receives a signal produced by a synthesizer and couples the received signal to two output ports. A pulse transmitter receives a pulse transmit-activate signal from a controller, receives an input signal from the hybrid coupler and, if the activate signal has been received, amplifies the received signal based on a predefined desired pulse output transmission setting. A frequency-modulation continuous-wave (FMCW) transmitter receives an FMCW transmit-activate signal from the controller, receives an input signal from the hybrid coupler and, if the activate signal has been received, amplifies the received input signal based on a predefined desired FMCW output transmission setting. An isolator protects the pulse transmitter during FMCW operation and also the FMCW transmitter from receiving power reflected off of pulse transmitter components.

Abstract: A plurality of mini radars that make the radar system conformable to a structure that it is attached or built into. A radar system includes a clock, a plurality of frequency modulated/continuous wave (FM/CW) radar units in signal communication with the clock and a processor in signal communication with the plurality of FM/CW radar units. Each of the plurality of FM/CW radar units includes a row of antenna elements.

Abstract: Systems and methods for creating a narrow vertical pathway of detection that permits the enforcement of a fixed “exclusion zone” that is narrow and does not widen with range. An advantage to this approach is that the zone or corridor does not widen with range, permitting a fixed exclusion zone that will ignore items that will pass above or below the wing. An exemplary system located on a vehicle includes at least two vertically separated antennas that receive radar reflection signals, a processor, and an output device. The processor receives the radar reflection signals received by the antennas, determines vertical position of any obstacles identified in the radar reflection signals and determines if the obstacles are within a predefined alert zone. The output device outputs an alert if any obstacle is within the alert zone. The predefined alert zone is related to a protruding portion of the vehicle.

Abstract: A high resolution, low power marine radar for use in applications such as the newly mandated barge/river radars that are to be used in very confined spaces such as canals. An example radar system includes frequency-modulated/continuous-wave (FM/CW) radar that uses very low transmitter power (a fraction of a watt) and has an exceptionally short sensing range of a few feet or even inches if needed.

Abstract: Housings for electrical or electronic components made using braid or woven fabric sheets having multiple sections treated with different materials as well as processes and materials for making such housings are disclosed.

Abstract: Systems and methods for automatically determining a noise threshold are provided. In one implementation, a system comprises: an antenna configured to gather data about a surrounding environment; a processing unit configured to remove samples representing target data from the gathered data; to estimate the noise floor from the gathered data with the removed target data; and to determine a noise threshold from the estimated noise floor; and a memory device configured to store the estimated noise floor.

Abstract: Systems and methods for radar altimeter antenna performance monitoring via reflected power measurements are provided. In one embodiment, a single antenna radar altimeter comprises: an antenna; a circulator coupled to the antenna; a transmitter coupled to the circulator; a receiver coupled to the circulator; wherein the circulator provides coupling of the transmitter and the receiver to the antenna while providing isolation between the transmitter and the receiver; a reflected power monitor positioned between the circulator and receiver; and a processor coupled to the reflected power monitor via a first analog-to-digital converter, the processor configured to compute and track reflected power measurement statistics from data generated by the reflected power monitor and provide a performance output indicating when one or more of the reflected power measurement statistics exceed a predetermined deviation threshold.

Abstract: Systems and methods for providing passive bird-strike avoidance. A passive L-band receiver system is located on an aircraft. The system includes a processor and an antenna having an array of four or more elements. The antenna configured to receive L-band signals. The processor receives the L-band signals from the antenna, determines if the received L-band signals indicate a target, determines distance, direction of travel and speed of any determined targets, determines if the target is a flock of birds based on the determined speed and determines if a hazard condition exists based on the distance, direction and speed.

Abstract: A plurality of mini radars that make the radar system conformable to a structure that it is attached or built into. A radar system includes a clock, a plurality of frequency modulated/continuous wave (FM/CW) radar units in signal communication with the clock and a processor in signal communication with the plurality of FM/CW radar units. Each of the plurality of FM/CW radar units includes a row of antenna elements.

Abstract: Systems and methods for radar altimeter antenna performance monitoring via reflected power measurements are provided. In one embodiment, a single antenna radar altimeter comprises: an antenna; a circulator coupled to the antenna; a transmitter coupled to the circulator; a receiver coupled to the circulator; wherein the circulator provides coupling of the transmitter and the receiver to the antenna while providing isolation between the transmitter and the receiver; a reflected power monitor positioned between the circulator and receiver; and a processor coupled to the reflected power monitor via a first analog-to-digital converter, the processor configured to compute and track reflected power measurement statistics from data generated by the reflected power monitor and provide a performance output indicating when one or more of the reflected power measurement statistics exceed a predetermined deviation threshold.

Abstract: A method for radar aided positioning of an air vehicle for approach and landing is described. The method includes integrating global navigation satellite system (GNSS) data and inertial data to calculate a position of the air vehicle, scanning the environment forward of the air vehicle with a radar, and accessing a database of terrain features and their radar signatures. The method further includes matching features in the radar scan data to the radar signatures in the database to determine an actual position of the air vehicle and synthesizing glide slope and localizer signals for the approach and landing based on the determined actual position.

Abstract: A high resolution, low power marine radar for use in applications such as the newly mandated barge/river radars that are to be used in very confined spaces such as canals. An example radar system includes frequency-modulated/continuous-wave (FM/CW) radar that uses very low transmitter power (a fraction of a watt) and has an exceptionally short sensing range of a few feet or even inches if needed.

Abstract: Systems and methods for reducing radar target processing. The systems include a processor configured to receive a first input from a cooperative surveillance source and a second input from a radar device. The first input includes cooperative target information, the second input includes cooperative and non-cooperative target information, and the processor is configured to process the first and second inputs to remove cooperative target information from the second input based on the first input to generate a modified radar output for use by an output device. The methods include receiving a first input including cooperative target information from a cooperative surveillance source, receiving a second input including cooperative and non-cooperative target information from a radar device, processing the first and second inputs to remove cooperative target information from the second input based on the first input, and generating a modified radar output based on the processed first and second inputs.

Abstract: Systems and methods for testing a signal generated by a Direct Digital Synthesizer (DDS) in a radar altimeter. In an embodiment of the method, a voltage signal derived by comparing a fixed reference frequency to a ramped frequency signal generated by the DDS based on a clock-based reference signal is generated. The generated voltage signal is integrated over a predefined range of clock signals. The integration is sampled at a previously defined clock tick. The sample is compared to a desired value and an indication that the radar altimeter is malfunctioning is provided if the comparison exceeds a predefined threshold value. The radar altimeter system is deactivated if an indication that the radar altimeter is malfunctioning has been provided.