Abstract: A sweep sensor may include a signal source, a propagation medium, and a detector. By transmitting an interrogating signal from the signal source into the propagation medium, detectable disturbances along the medium can physically alter the characteristics of the medium, which may cause a measurable change in the backscattered signal at the detector. Based on the change, it may be possible to locate the geographic origins of the physical disturbances along the propagation medium, or to determine the nature of the disturbances, or both. For example, it is generally possible to estimate the approximate distance between the detector and the disturbance given the time required to obtain the backscattered signal and the velocity of the signal source in the propagation medium. Further, in some embodiments, it is possible to quantify the amount of disturbance.

Abstract: A sweep sensor may include a signal source, a propagation medium, and a detector. By transmitting an interrogating signal from the signal source into the propagation medium, detectable disturbances along the medium can physically alter the characteristics of the medium, which may cause a measureable change in the backscattered signal at the detector. Based on the change, it may be possible to locate the geographic origins of the physical disturbances along the propagation medium, or to determine the nature of the disturbances, or both. For example, it is generally possible to estimate the approximate distance between the detector and the disturbance given the time required to obtain the backscattered signal and the velocity of the signal source in the propagation medium. Further, in some embodiments, it is possible to quantify the amount of disturbance.

Abstract: A sweep sensor may include a signal source, a propagation medium, and a detector. By transmitting an interrogating signal from the signal source into the propagation medium, detectable disturbances along the medium can physically alter the characteristics of the medium, which may cause a measurable change in the backscattered signal at the detector. Based on the change, it may be possible to locate the geographic origins of the physical disturbances along the propagation medium, or to determine the nature of the disturbances, or both. For example, it is generally possible to estimate the approximate distance between the detector and the disturbance given the time required to obtain the backscattered signal and the velocity of the signal source in the propagation medium. Further, in some embodiments, it is possible to quantify the amount of disturbance.

Abstract: A disturbance, such as vibration from human activity, is located along a fiberoptic waveguide configuration (301-304) with two interferometers (801, 802) of the same or different types, such as Mach-Zehnder, Sagnac, and Michelson interferometers. Carrier signals from a source (101) are split at the interferometer inputs (201, 202) and re-combined at the outputs (701, 702) after propagating through the detection zone (401), where phase variations are induced by the disturbance (501). Phase responsive receivers (901, 902) detect phase relationships (1001, 1002) between the carrier signals over time. A processor (1101) combines the phase relationships into composite signals according to equations that differ for different interferometer configurations, with a time lag between or a ratio of the composite signals representing the location of the disturbance.

Abstract: A sweep sensor may include a signal source, a propagation medium, and a detector. By transmitting an interrogating signal from the signal source into the propagation medium, detectable disturbances along the medium can physically alter the characteristics of the medium, which may cause a measurable change in the backscattered signal at the detector. Based on the change, it may be possible to locate the geographic origins of the physical disturbances along the propagation medium, or to determine the nature of the disturbances, or both. For example, it is generally possible to estimate the approximate distance between the detector and the disturbance given the time required to obtain the backscattered signal and the velocity of the signal source in the propagation medium. Further, in some embodiments, it is possible to quantify the amount of disturbance.

Abstract: The location of a physical disturbance along an optical waveguide is determined by measuring different propagation times for the resulting phase variation to propagate to phase responsive receivers at ends of bidirectional signal paths. Each receiver can have a coupler that functions as a beam combiner and as a beam splitter inserting the opposite signal. On each receiving end, the coupler provides one or more detectors with signals from which phase related independent variable values are taken, processed and mapped to phase angles. Relative phase angle versus time is derived for each opposite signal pair and correlated at a time difference, i.e., a difference in propagation time from which the location of the disturbance is resolved. Polarization sensitive and polarization insensitive examples are discussed with various optical fiber arrangements.

Abstract: A disturbance, such as vibration from human activity, is located along a fiberoptic waveguide configuration (301-304) with two interferometers (801, 802) of the same or different types, such as Mach-Zehnder, Sagnac, and Michelson interferometers. Carrier signals from a source (101) are split at the interferometer inputs (201, 202) and re-combined at the outputs (701, 702) after propagating through the detection zone (401), where phase variations are induced by the disturbance (501). Phase responsive receivers (901, 902) detect phase relationships (1001, 1002) between the carrier signals over time. A processor (1101) combines the phase relationships into composite signals according to equations that differ for different interferometer configurations, with a time lag between or a ratio of the composite signals representing the location of the disturbance.

Abstract: The location of a physical disturbance along an optical waveguide is determined by measuring different propagation times for the resulting phase variation to propagate to phase responsive receivers at ends of bidirectional signal paths. Each receiver can have a coupler that functions as a beam combiner and as a beam splitter inserting the opposite signal. On each receiving end, the coupler provides one or more detectors with signals from which phase related independent variable values are taken, processed and mapped to phase angles. Relative phase angle versus time is derived for each opposite signal pair and correlated at a time difference, i.e., a difference in propagation time from which the location of the disturbance is resolved. Polarization sensitive and polarization insensitive examples are discussed with various optical fiber arrangements.

Abstract: Polarization effects are managed to provide differential timing information for localizing disturbances affecting two or more counter-propagating light signals on one or more optical waveguides passing through a detection zone. Activity can be localized to a point for a security perimeter. Events causing optical disturbance can be mapped to points along a straight line, a perimeter or arbitrary pattern or an array. Events cause local changes in optical properties in the optical waveguide, in particular an optical fiber. Short term local changes are distinguishable from phase changes of light travel in the waveguide by managing the polarization state of input and output beams.

Abstract: Polarization effects are managed to provide differential timing information for localizing disturbances affecting two or more counter-propagating light signals on one or more optical waveguides passing through a detection zone. Activity can be localized to a point for a security perimeter. Events causing optical disturbance can be mapped to points along a straight line, a perimeter or arbitrary pattern or an array. Events cause local changes in optical properties in the optical waveguide, in particular an optical fiber. Short term local changes are distinguishable from phase changes of light travel in the waveguide, by managing the polarization state of input and output beams, combining orthogonal polarization components and other aspects. The changes in the states of polarization of the counter-propagating light signals are determined and the temporal spacing of corresponding changes in polarization state are resolved to pinpoint the location of the event along the optical fiber.

Abstract: An intrusion detection system with a distributed sensor system coupled with a plurality of secondary sensors is disclosed. The distributed sensor is deployed over a protected zone, and detects physical disturbances caused by intrusion into the zone. A plurality of physical disturbing devices is coupled to the distributed sensor to physically disturb the distributed sensor. A plurality of secondary sensors is employed as additional sensors to volumetrically extend the sensing zone, and is coupled with physically disturbing devices. A secondary sensor sends a signal to an associated physically disturbing device upon detecting an event to be monitored, and the signal operates the physically disturbing device to produce a physical disturbance that will be detected by the distributed sensor. Location of the event is identified by analyzing the disturbance and consequently by locating the physically disturbing device and the associated secondary sensor.

Abstract: Polarization effects are managed to provide differential timing information for localizing disturbances affecting two or more counter-propagating light signals on one or more optical waveguides passing through a detection zone. Activity can be localized to a point for a security perimeter. Events causing optical disturbance can be mapped to points along a straight line, a perimeter or arbitrary pattern or an array. Events cause local changes in optical properties in the optical waveguide, in particular an optical fiber. Short term local changes are distinguishable from phase changes of light travel in the waveguide, by managing the polarization state of input and output beams, combining orthogonal polarization components and other aspects. The changes in the states of polarization of the counter-propagating light signals are determined and the temporal spacing of corresponding changes in polarization state are resolved to pinpoint the location of the event along the optical fiber.

Abstract: Polarization effects are managed to provide differential timing information for localizing disturbances affecting two or more counter-propagating light signals on one or more optical waveguides passing through a detection zone. Activity can be localized to a point for a security perimeter. Events causing optical disturbance can be mapped to points along a straight line, a perimeter or arbitrary pattern or an array. Events cause local changes in optical properties in the optical waveguide, in particular an optical fiber. Short term local changes are distinguishable from phase changes of light travel in the waveguide by managing the polarization state of input and output beams.