Abstract: A method for bonding and encapsulating a sensor to a substrate by using a mold having a top surface, a bottom surface, a void, and a channel includes disposing the flexible mold in contact with a surface of the substrate. The method further includes passing the sensor through the channel and terminating the sensor within the void at an offset distance from the substrate. The method further includes filling the void and encapsulating the sensor with a substantially fixed volume and substantially fixed geometry of cement.

Abstract: Systems, methods, apparatuses and computer-readable storage media for navigating an unmanned aerial vehicle (UAV) using signals of opportunity are disclosed. The UAV may include a receiver for detecting a plurality of signals at two or more receiver elements. The UAV may estimate an angle of arrival (AoA) for at least two signals of the plurality of signals, and may estimate a position of the receiver based, at least in part, on the AoA for each of the at least two signals. Known locations of the transmitters that are transmitting the at least two signals may be used in conjunction with the AoAs to determine the estimate of the position of the receiver. More than two signals may be used to localize the estimated position of the receiver.

Abstract: Systems, methods, apparatuses and computer-readable storage media for navigating an unmanned aerial vehicle (UAV) using signals of opportunity are disclosed. The UAV may include a receiver for detecting a plurality of signals at two or more receiver elements. The UAV may estimate an angle of arrival (AoA) for at least two signals of the plurality of signals, and may estimate a position of the receiver based, at least in part, on the AoA for each of the at least two signals. Known locations of the transmitters that are transmitting the at least two signals may be used in conjunction with the AoAs to determine the estimate of the position of the receiver. More than two signals may be used to localize the estimated position of the receiver.

Abstract: A low-altitude altimeter (10) and a method of determining low altitudes for unmanned aerial vehicles (24). The altimeter includes at least two illuminators (12, 14), at least one sensor (16), and a computing device (18). The illuminators (12, 14) emit signals which are received by the sensor (16) in such a way that an angle at which they are received is determinable by the computing device (18). The computing device (18) processes each signal received by the sensor (16), determines the angle at which the sensor (16) received the signal, and, based thereon, determines the altitude of the unmanned aerial vehicle (24). When a first pair of illuminators are arranged along a fuselage axis, and a second pair of illuminators are arranged orthogonally to that axis, the computing device can combine first and second altitude, pitch angle, and roll angle measurements to provide a more refined altitude determination.

Abstract: A structural member such as a strut includes a composite material tube having metal end fittings that are attached to the tube by co-bonded, double shear joints. The double shear bond joint construction reduces the residual stress on the bonds that result from mismatch of the coefficients of thermal expansion of the composite tube and the metal end fittings. The ends of the fittings that are bonded to the tube may include a stepped profile that functions to limit the peak stresses in the bonds.

Abstract: A low-altitude altimeter (10) and a method of determining low altitudes for unmanned aerial vehicles (24). The altimeter includes at least two illuminators (12, 14), at least one sensor (16), and a computing device (18). The illuminators (12, 14) emit signals which are received by the sensor (16) in such a way that an angle at which they are received is determinable by the computing device (18). The computing device (18) processes each signal received by the sensor (16), determines the angle at which the sensor (16) received the signal, and, based thereon, determines the altitude of the unmanned aerial vehicle (24). When a first pair of illuminators are arranged along a fuselage axis, and a second pair of illuminators are arranged orthogonally to that axis, the computing device can combine first and second altitude, pitch angle, and roll angle measurements to provide a more refined altitude determination.

Abstract: A low-altitude altimeter (10) and a method of determining low altitudes for unmanned aerial vehicles (24). The altimeter includes at least two illuminators (12,14), at least one sensor (16), and a computing device (18). The illuminators (12,14) emit signals which are received by the sensor (16) in such a way that an angle at which they are received is determinable by the computing device (18). The computing device (18) processes each signal received by the sensor (16), determines the angle at which the sensor (16) received the signal, and, based thereon, determines the altitude of the unmanned aerial vehicle (24). When a first pair of illuminators are arranged along a fuselage axis, and a second pair of illuminators are arranged orthogonally to that axis, the computing device can combine first and second altitude, pitch angle, and roll angle measurements to provide a more refined altitude determination.

Abstract: A low-altitude altimeter (10) and a method of determining low altitudes for unmanned aerial vehicles (24). The altimeter includes at least two illuminators (12,14), at least one sensor (16), and a computing device (18). The illuminators (12,14) emit signals which are received by the sensor (16) in such a way that an angle at which they are received is determinable by the computing device (18). The computing device (18) processes each signal received by the sensor (16), determines the angle at which the sensor (16) received the signal, and, based thereon, determines the altitude of the unmanned aerial vehicle (24). When a first pair of illuminators are arranged along a fuselage axis, and a second pair of illuminators are arranged orthogonally to that axis, the computing device can combine first and second altitude, pitch angle, and roll angle measurements to provide a more refined altitude determination.

Abstract: A structural member such as a strut includes a composite material tube having metal end fittings that are attached to the tube by co-bonded, double shear joints. The double shear bond joint construction reduces the residual stress on the bonds that result from mismatch of the coefficients of thermal expansion of the composite tube and the metal end fittings. The ends of the fittings that are bonded to the tube may include a stepped profile that functions to limit the peak stresses in the bonds.

Abstract: An optical homodyne detection scheme for FM chirped lidar is described. The system performs de-chirping within a photodetector, and it does not require high-speed photo-detection or RF mixing. Embodiments are also described for dealing with phase noise.

Abstract: A structural member such as a strut includes a composite material tube having metal end fittings that are attached to the tube by co-bonded, double shear joints. The double shear bond joint construction reduces the residual stress on the bonds that result from mismatch of the coefficients of thermal expansion of the composite tube and the metal end fittings. The ends of the fittings that are bonded to the tube may include a stepped profile that functions to limit the peak stresses in the bonds.

Abstract: A method and system for a device to embed a low signal to interference plus noise ratio (SINR) communications signal into the backscatter of an illuminating signal. The illuminating signal may be acoustic or electromagnetic (EM) such as radio frequency (RF), light, or infrared (IR). The embedded communications signal may be recovered at a desired receiver.

Abstract: An apparatus and method for horizontally drilling for detecting subsurface features and avoiding such features during closed-loop control of an underground drilling machine. A horizontal drilling system includes a base machine capable of propelling a drill pipe rotationally and longitudinally underground. A cutting tool system is coupled to the drill pipe, and a control system controls the base machine. A detector is employed to detect a subsurface feature. A communication link is utilized for transferring data between the detector and the control system. The control system uses the data generated by the detector to modify control of the base machine in response to detection of the subsurface feature.

Abstract: A receiver system processes a received optical signal that carries user information. The receiver system includes a splitter, a first converter, a second converter, and a detection system. The splitter splits the received optical signal based on polarization into a first optical signal and a second optical signal. The first converter converts the first optical signal into a corresponding first electrical signal. The second converter also converts the second optical signal into a corresponding second electrical signal. The detection system applies radio frequency detection to the first electrical signal to generate a third electrical signal. The detection system applies radio frequency detection to the second electrical signal to generate a fourth electrical signal. The detection system then combines the third electrical signal and the fourth electrical signal to form a fifth electrical signal that carries the user information.

Abstract: An apparatus and method for horizontally drilling provides for detecting subsurface features and avoiding such features during closed-loop control of an underground drilling machine. A horizontal drilling system includes a base machine capable of propelling a drill pipe rotationally and longitudinally underground. A cutting tool system is coupled to the drill pipe, and a control system controls the base machine. A detector is employed to detect a subsurface feature. A communication link is utilized for transferring data between the detector and the control system. The control system uses the data generated by the detector to modify control of the base machine in response to detection of the subsurface feature.

Abstract: An apparatus and method for horizontally drilling provides for detecting subsurface features and avoiding such features during closed-loop control of an underground drilling machine. A horizontal drilling system includes a base machine capable of propelling a drill pipe rotationally and longitudinally underground. A cutting tool system is coupled to the drill pipe, and a control system controls the base machine. A detector is employed to detect a subsurface feature. A communication link is utilized for transferring data between the detector and the control system. The control system uses the data generated by the detector to modify control of the base machine in response to detection of the subsurface feature.

Abstract: An apparatus and method for determining a location and an orientation of an underground boring tool by employment of a radar-like probe and detection technique. The boring tool is provided with a device which generates a specific signature signal in response to a probe signal transmitted from above the ground. Cooperation between the probe signal transmitter at ground level and the signature signal generating device provided at the underground boring tool results in accurate detection of the boring tool location and, if desired, orientation, despite the presence of a large background signal. Precision detection of the boring tool location and orientation enables the operator to accurately locate the boring tool during operation and, if provided with a directional capacity, avoid buried obstacles such as utilities and other hazards. The signature signal produced by the boring tool may be generated either passively or actively, and may be a microwave or an acoustic signal.

Abstract: An apparatus and method for determining a location and an orientation of an underground boring tool by employment of a radar-like probe and detection technique. The boring tool is provided with a device which generates a specific signature signal in response to a probe signal transmitted from above the ground. Cooperation between the probe signal transmitter at ground level and the signature signal generating device provided at the underground boring tool results in accurate detection of the boring tool location and, if desired, orientation, despite the presence of a large background signal. Precision detection of the boring tool location and orientation enables the operator to accurately locate the boring tool during operation and, if provided with a directional capacity, avoid buried obstacles such as utilities and other hazards. The signature signal produced by the boring tool may be generated either passively or actively, and may be a microwave or an acoustic signal.

Abstract: An apparatus and method for determining a location and an orientation of an underground boring tool by employment of a radar-like probe and detection technique. The boring tool is provided with a device which generates a specific signature signal in response to a probe signal transmitted from above the ground. Cooperation between the probe signal transmitter at ground level and the signature signal generating device provided at the underground boring tool results in accurate detection of the boring tool location and, if desired, orientation, despite the presence of a large background signal. Precision detection of the boring tool location and orientation enables the operator to accurately locate the boring tool during operation and, if provided with a directional capacity, avoid buried obstacles such as utilities and other hazards. The signature signal produced by the boring tool may be generated either passively or actively, and may be a microwave or an acoustic signal.

Abstract: An apparatus and method for locating an underground object or structure by employment of a radar-like probe and detection technique is disclosed. The underground structure is provided with a device which generates a specific signature signal in response to a probe signal transmitted from above the ground. Cooperative action between the probe signal transmitter at ground level and the signature signal generating device provided on the underground object provides for accurate detection of the subsurface object, despite the presence of a large background noise signal. The depth and, if desired, orientation of the underground object may also be determined using the signature signal generated by the signature signal generating device mounted to the underground object. Orientation information may be encoded on the signature signal or transmitted as an information signal separate from the signature signal. The probe signal may be microwave or acoustic.