Abstract: Disclosed is a signal processing method for a distributed acoustic sensing system (DAS), including receiving a set of scattered signals, each of which was scattered at a different location along an optical path and corresponds to a respective spatial channel. Each scattered signal is interfered with a local oscillator signal, and processed to generate a complex carrier signal whose modulation is related to an instantaneous frequency of an acoustic modulation at the scattering location. In order to improve the signal-to-noise ratio (SNR), complex carrier signals from multiple spatial channels are summed together, so that an instantaneous frequency corresponding to those channels can be estimated. The generation each complex carrier signal involves using a reference complex carrier signal for that channel. When the estimated instantaneous frequency corresponding to a set of spatial channels fulfils a predetermined condition, the reference complex carrier signal for those spatial channels is updated.

Abstract: An optical detection system defined by a distributed acoustic sensing system (“DAS”) and related signal processing. The DAS has a coherent light source that generates a light signal; a launch stage configured to receive the light signal, generate a test signal, and launch the test signal along an optical path. The test signal has a periodic step increase in frequency. A local oscillator stage generates a local oscillator signal having a periodic step increase in frequency which is offset relative to the test signal in each of a time domain and a frequency domain, with the offset being by a user defined time delay and offset by a system defined frequency shift relative to the test signal. A detector stage receives the local oscillator signal and a scattered signal from the optical path. An output signal is defined by interference terms between the scattered signal and the local oscillator signal.

Abstract: Disclosed are signal processing methods for an optical detection system, and corresponding systems. An example is a signal processing method for a distributed acoustic sensing system which utilizes spread spectrum pulses transmitted along an optical path, where a scattered signal that was scattered at a scattering location along an optical path is received and interfered with a local oscillator signal to generate a first carrier signal that is modulated by a phase difference between the local oscillator and scattered signals. The first carrier signal is then processed to generate a second carrier signal that is modulated by a spatial differential of the phase difference. Pulse compression is then performed on the second carrier signal. The spatial differential of the phase difference is directly related to the strain (or acoustic environment) of the optical path at the scattering location, and so enables the strain at the scattering location to be estimated.

Abstract: Disclosed are signal processing methods for an optical detection system, and corresponding systems. An example is a signal processing method for a distributed acoustic sensing system which utilizes spread spectrum pulses transmitted along an optical path, where a scattered signal that was scattered at a scattering location along an optical path is received and interfered with a local oscillator signal to generate a first carrier signal that is modulated by a phase difference between the local oscillator and scattered signals. The first carrier signal is then processed to generate a second carrier signal that is modulated by a spatial differential of the phase difference. Pulse compression is then performed on the second carrier signal. The spatial differential of the phase difference is directly related to the strain (or acoustic environment) of the optical path at the scattering location, and so enables the strain at the scattering location to be estimated.

Abstract: The present disclosure relates to signal processing methods for an optical detection system, and systems for carrying out such processing. In particular, disclosed is a signal processing method for filtering the phase of an input signal, the method includes: receiving an input signal; applying an N-stage delay line to the input signal to generate a plurality of delayed signals, where N is an integer which may refer to the order of the filter, the value of which may be preselected to provide a desired balance between performance and processing power (as higher order filters may produce better results at the cost of increased processing power); applying a respective exponentiation to each delayed signal to generate a plurality of phase modified signals; and cumulatively multiplying each of the phase modified signals to generate a filtered signal.

Abstract: The invention provides an optical measurement system for performing a combination of Distributed Acoustic Sensing (DAS), Distributed Temperature Sensing (DTS), and/or Distributed Strain and Temperature Sensing (DSTS) on a same optical path (e.g. an optical fibre). The optical system comprises a coherent light source configured to generate a light signal, a launch stage configured to receive the light signal from the light source and generate a pulsed test signal and launch the test signal along an optical path, and a local oscillator stage configured to generate a local oscillator signal. A first detector stage is configured to receive the local oscillator signal and a scattered signal from the optical path, and to interfere the local oscillator signal with the scattered signal.

Abstract: Disclosed is a signal processing method for a distributed acoustic sensing system (DAS), where a scattered signal that was scattered at a scattering location along an optical path is received and interfered with a local oscillator signal to generate a first carrier signal that is modulated by a phase difference between the local oscillator signal and the scattered signal. The first carrier signal is then digitally processed in order to generate a second carrier signal that is modulated by a spatial differential of the phase difference. The spatial differential of the phase difference is directly related to the strain (or acoustic environment) of the optical path at the scattering location, and so enables the strain at the scattering location to be estimated.

Abstract: Disclosed are signal processing methods for an optical detection system, and corresponding systems. An example is a signal processing method for a distributed acoustic sensing system which utilizes spread spectrum pulses transmitted along an optical path, where a scattered signal that was scattered at a scattering location along an optical path is received and interfered with a local oscillator signal to generate a first carrier signal that is modulated by a phase difference between the local oscillator and scattered signals. The first carrier signal is then processed to generate a second carrier signal that is modulated by a spatial differential of the phase difference. Pulse compression is then performed on the second carrier signal. The spatial differential of the phase difference is directly related to the strain (or acoustic environment) of the optical path at the scattering location, and so enables the strain at the scattering location to be estimated.

Abstract: Disclosed is a signal processing method for a distributed acoustic sensing system (DAS), including receiving a set of scattered signals, each of which was scattered at a different location along an optical path and corresponds to a respective spatial channel. Each scattered signal is interfered with a local oscillator signal, and processed to generate a complex carrier signal whose modulation is related to an instantaneous frequency of an acoustic modulation at the scattering location. In order to improve the signal-to-noise ratio (SNR), complex carrier signals from multiple spatial channels are summed together, so that an instantaneous frequency corresponding to those channels can be estimated. The generation each complex carrier signal involves using a reference complex carrier signal for that channel. When the estimated instantaneous frequency corresponding to a set of spatial channels fulfils a predetermined condition, the reference complex carrier signal for those spatial channels is updated.

Abstract: Systems and methods are provided for user interface deployment that include a server with a cloud application and a client device with a client application. The cloud application is a fully functional application, such as a headless application, and transmits scene graph data including presentation data and behavior data for a first set of user interface elements viewable at the client device in a first operational state. The client application locally renders the first set of user interface elements on a client device display to locally render the portion of the scene graph related to the first operational state. In response to a user input, the client application transmits event or state data to the cloud application and may perform an action associated with the user input while awaiting receipt of updated scene graph data, possibly related to a subsequent operational state, reducing or eliminating the perception of latency.

Abstract: Disclosed is a signal processing method for a distributed acoustic sensing system (DAS), where a scattered signal that was scattered at a scattering location along an optical path is received and interfered with a local oscillator signal to generate a first carrier signal that is modulated by a phase difference between the local oscillator signal and the scattered signal. The first carrier signal is then digitally processed in order to generate a second carrier signal that is modulated by a spatial differential of the phase difference. The spatial differential of the phase difference is directly related to the strain (or acoustic environment) of the optical path at the scattering location, and so enables the strain at the scattering location to be estimated.

Abstract: Systems and methods are provided for user interface deployment that include a server with a cloud application and a client device with a client application. The cloud application is a fully functional application, such as a headless application, and transmits scene graph data including presentation data and behavior data for a first set of user interface elements viewable at the client device in a first operational state. The client application locally renders the first set of user interface elements on a client device display to locally render the portion of the scene graph related to the first operational state. In response to a user input, the client application transmits event or state data to the cloud application and may perform an action associated with the user input while awaiting receipt of updated scene graph data, possibly related to a subsequent operational state, reducing or eliminating the perception of latency.

Abstract: An improved technique for acoustic sensing involves, in one embodiment, launching into a medium, a plurality of groups of pulse-modulated electromagnetic-waves. The frequency of electromagnetic waves in a pulse within a group differs from the frequency of the electromagnetic waves in another pulse within the group. The energy scattered by the medium is detected and, in one embodiment, the beat signal may be used to determine a characteristic of the environment of the medium. For example, if the medium is a buried optical fiber into which light pulses have been launched in accordance with the invention, the presence of acoustic waves within the region of the buried fiber can be detected.

Abstract: An improved technique for acoustic sensing involves, in one embodiment, launching into a medium, a plurality of groups of pulse-modulated electromagnetic-waves. The frequency of electromagnetic waves in a pulse within a group differs from the frequency of the electromagnetic waves in another pulse within the group. The energy scattered by the medium is detected and, in one embodiment, may be used to determine a characteristic of the environment of the medium. For example, if the medium is a buried optical fiber into which light pulses have been launched in accordance with the invention, the presence of acoustic waves within the region of the buried fiber can be detected.

Abstract: An improved technique for acoustic sensing involves, in one embodiment, launching into a medium, a plurality of groups of pulse-modulated electromagnetic-waves. The frequency of electromagnetic waves in a pulse within a group differs from the frequency of the electromagnetic waves in another pulse within the group. The energy scattered by the medium is detected and, in one embodiment, may be used to determine a characteristic of the environment of the medium. For example, if the medium is a buried optical fiber into which light pulses have been launched in accordance with the invention, the presence of acoustic waves within the region of the buried fiber can be detected.

Abstract: An improved technique for acoustic sensing involves, in one embodiment, launching into a medium, a plurality of groups of pulse-modulated electromagnetic-waves. The frequency of electromagnetic waves in a pulse within a group differs from the frequency of the electromagnetic waves in another pulse within the group. The energy scattered by the medium is detected and, in one embodiment, the beat signal may be used to determine a characteristic of the environment of the medium. For example, if the medium is a buried optical fiber into which light pulses have been launched in accordance with the invention, the presence of acoustic waves within the region of the buried fiber can be detected.

Abstract: Systems and methods are provided for user interface deployment that include a server with a cloud application and a client device with a client application. The cloud application is a fully functional application, such as a headless application, and transmits scene graph data including presentation data and behavior data for a first set of user interface elements viewable at the client device in a first operational state. The client application locally renders the first set of user interface elements on a client device display to locally render the portion of the scene graph related to the first operational state. In response to a user input, the client application transmits event or state data to the cloud application and may perform an action associated with the user input while awaiting receipt of updated scene graph data, possibly related to a subsequent operational state, reducing or eliminating the perception of latency.

Abstract: An improved technique for acoustic sensing involves, in one embodiment, launching into a medium, a plurality of groups of pulse-modulated electromagnetic-waves. The frequency of electromagnetic waves in a pulse within a group differs from the frequency of the electromagnetic waves in another pulse within the group. The energy scattered by the medium is detected and, in one embodiment, may be used to determine a characteristic of the environment of the medium. For example, if the medium is a buried optical fiber into which light pulses have been launched in accordance with the invention, the presence of acoustic waves within the region of the buried fiber can be detected.

Abstract: An improved technique for acoustic sensing involves, in one embodiment, launching into a medium, a plurality of groups of pulse-modulated electromagnetic-waves. The frequency of electromagnetic waves in a pulse within a group differs from the frequency of the electromagnetic waves in another pulse within the group. The energy scattered by the medium is detected and, in one embodiment, the beat signal may be used to determine a characteristic of the environment of the medium. For example, if the medium is a buried optical fiber into which light pulses have been launched in accordance with the invention, the presence of acoustic waves within the region of the buried fiber can be detected.

Abstract: Systems and methods are provided for user interface deployment that include a server with a cloud application and a client device with a client application. The cloud application is a fully functional application, such as a headless application, and transmits scene graph data including presentation data and behavior data for a first set of user interface elements viewable at the client device in a first operational state. The client application locally renders the first set of user interface elements on a client device display to locally render the portion of the scene graph related to the first operational state. In response to a user input, the client application transmits event or state data to the cloud application and may perform an action associated with the user input while awaiting receipt of updated scene graph data, possibly related to a subsequent operational state, reducing or eliminating the perception of latency.