Abstract: Systems and methods for using velocity measurements to adjust Doppler filter bandwidth are provided herein. In certain embodiments, a method for adjusting bandwidth for at least one Doppler filter in a Doppler beam sharpened radar altimeter comprises receiving a velocity measurement; adjusting the bandwidth of the at least one Doppler filter based on the velocity measurement; and transmitting a radar beam, wherein the radar beam is aimed toward a surface. The method further comprises receiving at least one reflected signal, wherein the at least one reflected signal is a reflection of the radar beam being reflected off of at least one portion of the surface; and filtering the at least one reflected signal with the at least one Doppler filter to form at least one Doppler beam.

Abstract: Systems and methods for using velocity measurements to adjust Doppler filter bandwidth are provided herein. In certain embodiments, a method for adjusting bandwidth for at least one Doppler filter in a Doppler beam sharpened radar altimeter comprises receiving a velocity measurement; adjusting the bandwidth of the at least one Doppler filter based on the velocity measurement; and transmitting a radar beam, wherein the radar beam is aimed toward a surface. The method further comprises receiving at least one reflected signal, wherein the at least one reflected signal is a reflection of the radar beam being reflected off of at least one portion of the surface; and filtering the at least one reflected signal with the at least one Doppler filter to form at least one Doppler beam.

Abstract: A tunnel boring machine (90) having a rotating cutter head (93) that rotatably supports a plurality of cutter assemblies (10). A plurality of instrument packages (50) are attached to the rotating cutter head, each instrument package having a distal end in contact with an associated cutter assembly. The instrument packages include a plurality of sensors including an accelerometer (32), magnetometer (33) and temperature sensor (34), for monitoring the associated cutter assembly. The sensors are mounted in a distal end of the instrument packages that is biased to remain in contact with the cutter assembly. The instrument packages include a wireless transmitter, and they are interconnected in a mesh or peer to peer network. A power supply (176) such as a battery pack is provided for each instrument package. The data from the sensors may be used to control operation of the tunnel boring machine and/or to monitor the condition of the cutter assemblies.

Abstract: A method of compensating for component errors within a radar altimeter is described. The method includes periodically switching transmit pulses from a transmit antenna to a programmable delay device, calculating an altitude based on a transmit pulse received from the programmable delay device, comparing the calculated altitude to an expected altitude, the expected altitude based on a pre-set delay through the programmable delay device, and compensating an altitude measured by the radar altimeter, based on transmit pulses output through the transmit antenna, by an error correction amount based on a difference between the calculated altitude and expected altitudes.

Abstract: The methods and systems described herein relate to a recuperative combustion system that recuperates energy from fuel combustion that would otherwise be lost. The recuperative combustion system minimizes or eliminates the need for an air separator unit through the use of a clean water splitter section, consisting of a thermochemical cycle or high-temperature electrolysis. Water is split into its component hydrogen and oxygen, primarily with process heat from the combustion process. The oxygen produced by the water splitter provides oxygen necessary for oxy-fuel combustion, thereby reducing or eliminating the need for the power intensive air separator unit and/or external oxygen source, significantly increasing the efficiency of the oxy-fuel combustion cycle. Hydrogen produced by the water splitter may be used for a variety of industrial uses, or combined with carbon dioxide (captured from the flue gases produced by said combustion process) to produce methanol.

Abstract: A radar sensor is described that includes a radar transmitter, a radar receiver configured to receive reflected returns of signals output by the radar transmitter, and a signal processing unit configured to process signals received by the radar receiver. The signal processing unit includes a comparator, a first filter comprising an output coupled to a reference input of the comparator, and a second filter comprising an output coupled to a signal input of the comparator. The first and second filters are configured to receive a common input related to the reflected returns. The first filter is configured to have a time constant such that a rise time of the first filter output is faster than a rise time of the second filter output.

Abstract: A tunnel boring machine (90) having a rotating cutter head (93) that rotatably supports a plurality of cutter assemblies (10). A plurality of instrument packages (50) are attached to the rotating cutter head, each instrument package having a distal end in contact with an associated cutter assembly. The instrument packages include a plurality of sensors including an accelerometer (32), magnetometer (33) and temperature sensor (34), for monitoring the associated cutter assembly. The sensors are mounted in a distal end of the instrument packages that is biased to remain in contact with the cutter assembly. The instrument packages include a wireless transmitter, and they are interconnected in a mesh or peer to peer network. A power supply (176) such as a battery pack is provided for each instrument package. The data from the sensors may be used to control operation of the tunnel boring machine and/or to monitor the condition of the cutter assemblies.

Abstract: A method of compensating for component errors within a radar altimeter is described. The method includes periodically switching transmit pulses from a transmit antenna to a programmable delay device, calculating an altitude based on a transmit pulse received from the programmable delay device, comparing the calculated altitude to an expected altitude, the expected altitude based on a pre-set delay through the programmable delay device, and compensating an altitude measured by the radar altimeter, based on transmit pulses output through the transmit antenna, by an error correction amount based on a difference between the calculated altitude and expected altitudes.

Abstract: In one aspect, a method of radar altimeter operation including a time dependent gain control is described. The method comprises triggering a Sensitivity Time Control (STC) gain control signal at a pulse repetition frequency (PRF) of a transmit pulse to attenuate interference from at least one of an antenna leakage signal and a signal reflected from equipment. The method also includes shaping the STC gain control signal from no attenuation at a first time, before a transmitter sends the transmit pulse, to a stable maximum attenuation at the time the transmitter sends the transmit pulse, to no attenuation at a second time, after the transmitter sends the transmit pulse. The method also includes matching a bandwidth of an intermediate frequency (IF) amplifier to the pulse width of a transmitted pulse.

Abstract: In one aspect, a method of radar altimeter operation, the altimeter including a high frequency counter coupled to a processor is described. The method comprises providing a continuous wave to the high frequency counter upon receipt of a transmit pulse, counting the cycles of the continuous wave, discontinuing counting of the continuous wave cycles upon receipt of a return pulse, outputting a count from the high frequency counter to the processor, and operating the processor to convert the count to an altitude.

Abstract: A method of delaying propagation of a radio frequency (RF) signal through a circuit is described. The method comprises receiving data that represents a delay time interval, providing an RF signal when a start pulse triggers a memory device, initiating a count through the delay time interval based on receipt of a start pulse, and outputting the RF signal after the delay time interval has expired.

Abstract: A method for phase calibrating antennas in a radar system is disclosed. The method comprises providing a transmit antenna and two or more receive antennas, the receive antennas each in communication with a respective receiver channel. A radio frequency pulse having a leakage pulse is transmitted from the transmit antenna. The leakage pulse is received at each of the receive antennas and respective receiver channel. The relative phase change between the receive antennas is determined by using the leakage pulse as a reference signal.

Abstract: In one aspect, a method of radar altimeter operation including a time dependent gain control is described. The method comprises triggering a Sensitivity Time Control (STC) gain control signal at a pulse repetition frequency (PRF) of a transmit pulse to attenuate interference from at least one of an antenna leakage signal and a signal reflected from equipment. The method also includes shaping the STC gain control signal from no attenuation at a first time, before a transmitter sends the transmit pulse, to a stable maximum attenuation at the time the transmitter sends the transmit pulse, to no attenuation at a second time, after the transmitter sends the transmit pulse. The method also includes matching a bandwidth of an intermediate frequency (IF) amplifier to the pulse width of a transmitted pulse.

Abstract: A method of delaying propagation of a radio frequency (RF) signal through a circuit is described. The method comprises receiving data that represents a delay time interval, providing an RF signal when a start pulse triggers a memory device, initiating a count through the delay time interval based on receipt of a start pulse, and outputting the RF signal after the delay time interval has expired.

Abstract: A programmable circuit for controlling a detonation altitude of a radar equipped munition is provided. The circuit comprises means for calculating a velocity of the munition while the munition is operating in a pulse mode at an altitude greater than the desired detonation altitude and means, responsive to the means for calculating the velocity of the munition, for determining when the munition is at a reference altitude in order to operate the munition in a continuous wave transmission mode. The circuit further comprises means, responsive to the means for determining, for calculating a time representing when the vehicle will reach the desired detonation altitude based on the calculated velocity and the determined reference altitude, and means, responsive to the means for calculating the time representing when the vehicle will reach the desired detonation altitude, for generating a fusing signal to detonate the munition after the calculated time has passed.

Abstract: A radar processor for controlling detonation of a munition and operable to receive a detonation altitude from an external source is provided. The radar processor is configured to set a first range gate and a reference range gate based on the received detonation altitude, and cause a radar transmitter to operate in a continuous wave mode, for a predetermined period, upon receipt of radar return signals through the first range gate. The radar processor calculates a velocity of the munition from continuous wave return signals, and calculates a time delay for outputting a detonation signal based on the received detonation altitude, the calculated velocity, and a reference altitude of the munition, the altitude of the munition calculated based upon receipt of radar return signals through the reference range gate. The radar transmitter operates in a pulse mode while the munition is outside the reference range gate.

Abstract: A method for phase calibrating antennas in a radar system is disclosed. The method comprises providing a transmit antenna and two or more receive antennas, the receive antennas each in communication with a respective receiver channel. A radio frequency pulse having a leakage pulse is transmitted from the transmit antenna. The leakage pulse is received at each of the receive antennas and respective receiver channel. The relative phase change between the receive antennas is determined by using the leakage pulse as a reference signal.

Abstract: A radar processor for controlling detonation of a munition and operable to receive a detonation altitude from an external source is provided. The radar processor is configured to set a first range gate and a reference range gate based on the received detonation altitude, and cause a radar transmitter to operate in a continuous wave mode, for a predetermined period, upon receipt of radar return signals through the first range gate. The radar processor calculates a velocity of the munition from continuous wave return signals, and calculates a time delay for outputting a detonation signal based on the received detonation altitude, the calculated velocity, and a reference altitude of the munition, the altitude of the munition calculated based upon receipt of radar return signals through the reference range gate. The radar transmitter operates in a pulse mode while the munition is outside the reference range gate.

Abstract: A method for controlling a detonation altitude of a radar equipped munition is described. The method includes calculating a velocity of the munition while the munition is at an altitude greater than the desired detonation altitude, determining when the munition is at a reference altitude, and calculating a time representing when the vehicle will reach the desired detonation altitude based on the calculated velocity and determined reference altitude. The method also includes generating a fusing signal to detonate the munition after the calculated time has passed.

Abstract: A radar sensor is described that includes a radar transmitter, a radar receiver configured to receive reflected returns of signals output by the radar transmitter, and a signal processing unit configured to process signals received by the radar receiver. The signal processing unit includes a comparator, a first filter comprising an output coupled to a reference input of the comparator, and a second filter comprising an output coupled to a signal input of the comparator. The first and second filters are configured to receive a common input related to the reflected returns. The first filter is configured to have a time constant such that a rise time of the first filter output is faster than a rise time of the second filter output.