Abstract: The invention provides a method of estimating an input count rate of a radiation pulse detector from a detector signal where some individual signal pulses making up the detector signal are closely spaced in time less than a minimum reliable detection gap. In one aspect, the individual signal pulses are detected using a detection algorithm and a plurality of interval start times are defined each interposed with at least one of the detected individual signal pulse arrival times, each interval start time being later by at least the minimum reliable detection gap than a corresponding most recent detected individual signal pulse arrival time. A corresponding plurality of individual signal pulse arrival intervals are calculated between each of the interval start times and a corresponding next detected individual signal pulse arrival time.

Abstract: The invention provides a method of estimating an input count rate of a radiation pulse detector from a detector signal where some individual signal pulses making up the detector signal are closely spaced in time less than a minimum reliable detection gap (104,105; tc, td). In one aspect, the individual signal pulses are detected using a detection algorithm and a plurality of interval start times (sk) are defined each interposed with at least one of the detected individual signal pulse arrival times (tk), each interval start time (sk) being later by at least the minimum reliable detection gap than a corresponding most recent detected individual signal pulse arrival time (tk?1). A corresponding plurality of individual signal pulse arrival intervals are calculated between each of the interval start times (sk) and a corresponding next detected individual signal pulse arrival time (tk).

Abstract: A method and apparatus for resolving individual signals in detector output data are disclosed. One inventive aspect includes a processing circuit configured to receive detector output data wherein the detector output data may be stepped data or non-stepped data; transform the detector output data to produce stepped data wherein the detector output data is received as non-stepped data; detect at least one signal at least partially based on the stepped data; and estimate a parameter associated with the signal, wherein estimating the parameter may preferably comprise estimating a signal energy or signal time of arrival associated with the signal.

Abstract: A device and method for material characterization are provided. In one aspect, the method includes detecting packets of radiation emanating from within or passing through one or more items of freight or baggage as a result of irradiation by incident radiation, using a plurality of detectors, each of the detectors being configured to produce an electrical pulse caused by the detected packets having a characteristic size or shape dependent on an energy of the packets. The method further includes processing each of the electrical pulses using one or more digital processors to determine the characteristic size or shape, generating a screening detector energy spectrum for each of the detectors of the energies of the packets detected, and measuring an effective atomic number Z of an unknown material associated with the one or more items of freight or baggage based on the screening detector energy spectra in comparison with calibration measurements.

Abstract: A device and method for material characterization are provided. In one aspect, the method includes detecting packets of radiation emanating from within or passing through one or more items of freight or baggage as a result of irradiation by incident radiation, using a plurality of detectors, each of the detectors being configured to produce an electrical pulse caused by the detected packets having a characteristic size or shape dependent on an energy of the packets. The method further includes processing each of the electrical pulses using one or more digital processors to determine the characteristic size or shape, generating a screening detector energy spectrum for each of the detectors of the energies of the packets detected, and measuring an effective atomic number Z of an unknown material associated with the one or more items of freight or baggage based on the screening detector energy spectra in comparison with calibration measurements.

Abstract: A method and apparatus for resolving individual signals in detector output data by obtaining an impulse response characterizing a detector. The method further includes obtaining digitized detector output data in a form of a digital time series and making estimates of a signal temporal position of at least one signal present in the detector output data. The method further includes forming a mathematical model based on the digital time series and determining an amplitude of the at least one signal indicative of an event based on the mathematical model.

Abstract: A method for locating a pulse in detector output data, comprising fitting one or more functions to the detector output data; and determining a location and an amplitude of a peak of said pulse from said one or more functions. The one or more functions may be are a function of time.

Abstract: A method and apparatus for resolving individual signals in detector output data are disclosed. One inventive aspect includes a processing circuit configured to receive detector output data wherein the detector output data may be stepped data or non-stepped data; transform the detector output data to produce stepped data wherein the detector output data is received as non-stepped data; detect at least one signal at least partially based on the stepped data; and estimate a parameter associated with the signal, wherein estimating the parameter may preferably comprise estimating a signal energy or signal time of arrival associated with the signal.

Abstract: A method and apparatus for borehole logging, the method comprising collecting detector output data from a radiation detector of a borehole logging tool, and resolving individual signals in the detector output data by (i) determining a signal form of signals present in the data, (ii) making parameter estimates of one or more parameters of the signals, wherein the one or more parameters comprise at least a signal temporal position, and (iii) determining the energy of each of the signals from at least the signal form and the parameter estimates. The logging tool is shorter, logging tool speed is greater, dwell time is shorter and/or resolution is improved.

Abstract: A screening method and apparatus, the method comprising irradiating a subject for screening with excitation radiation, collecting detector output data from a radiation detector located near the subject, and resolving individual signals in the detector output data by (i) determining a signal form of signals present in the data, (ii) making parameter estimates of one or more parameters of the signals, wherein the one or more parameters comprise at least a signal temporal position, and (iii) determining the energy of each of the signals from at least the signal form and the parameter estimates. The screening time is shorter, dwell time is shorter, resolution is improved and/or throughput is increased.

Abstract: A method and apparatus for resolving individual signals in detector output data, the method comprising obtaining or expressing the detector output data as a digital series, obtaining or determining a signal form of signals present in the data, forming a transformed signal form by transforming the signal form according to a mathematical transform, forming a transformed series by transforming the digital series according to the mathematical transform, the transformed series comprising transformed signals, evaluating a function of at least the transformed series and the transformed signal form and thereby providing a function output, determining at least one parameter of the function output based on a model of the function output, and determining a parameter of the signals from the at least one determined parameter of the function output. The method may include forming the model by modelling the function output.

Abstract: A method for locating a pulse in detector output data, comprising fitting one or more functions to the detector output data; and determining a location and an amplitude of a peak of said pulse from said one or more functions. The one or more functions may be are a function of time.

Abstract: An imaging method and apparatus are provided. The method includes collecting detector output data from a radiation detector positioned near a subject provided with a radio-active tracer The method further includes resolving individual signals in the detector output data by determining a signal form of signals present in the data, and making parameter estimates of one or more parameters of the signal. The one or more parameters include at least a signal temporal position. The method further includes determining the energy of each of the signals from at least the signal form and the parameter estimates.

Abstract: A method and apparatus for resolving individual signals in detector output data by obtaining an impulse response characterizing a detector. The method further includes obtaining digitized detector output data in a form of a digital time series and making estimates of a signal temporal position of at least one signal present in the detector output data. The method further includes forming a mathematical model based on the digital time series and determining an amplitude of the at least one signal indicative of an event based on the mathematical model.

Abstract: A method and apparatus for resolving individual signals in detector output data, the method comprising obtaining or expressing the detector output data as a digital series, obtaining or determining a signal form of signals present in the data, forming a transformed signal form by transforming the signal form according to a mathematical transform, forming a transformed series by transforming the digital series according to the mathematical transform, the transformed series comprising transformed signals, evaluating a function of at least the transformed series and the transformed signal form and thereby providing a function output, determining at least one parameter of the function output based on a model of the function output, and determining a parameter of the signals from the at least one determined parameter of the function output. The method may include forming the model by modelling the function output.

Abstract: An imaging method and apparatus, the method comprising collecting detector output data from a radiation detector positioned near a subject provided with a radio-active tracer, and resolving individual signals in the detector output data by (i) determining a signal form of signals present in the data, (ii) making parameter estimates of one or more parameters of the signals, wherein the one or more parameters comprise at least a signal temporal position, and (iii) determining the energy of each of the signals from at least the signal form and the parameter estimates. The acceptable subject to detector distance is reduced or increased, spatial resolution is improved, tracer dose or concentration is reduced, subject radiation exposure is reduced and/or scanning time is reduced.

Abstract: A method and apparatus for borehole logging, the method comprising collecting detector output data from a radiation detector of a borehole logging tool, and resolving individual signals in the detector output data by (i) determining a signal form of signals present in the data, (ii) making parameter estimates of one or more parameters of the signals, wherein the one or more parameters comprise at least a signal temporal position, and (iii) determining the energy of each of the signals from at least the signal form and the parameter estimates. The logging tool is shorter, logging tool speed is greater, dwell time is shorter and/or resolution is improved.

Abstract: A screening method and apparatus, the method comprising irradiating a subject for screening with excitation radiation, collecting detector output data from a radiation detector located near the subject, and resolving individual signals in the detector output data by (i) determining a signal form of signals present in the data, (ii) making parameter estimates of one or more parameters of the signals, wherein the one or more parameters comprise at least a signal temporal position, and (iii) determining the energy of each of the signals from at least the signal form and the parameter estimates. The screening time is shorter, dwell time is shorter, resolution is improved and/or throughput is increased.

Abstract: A method and apparatus for resolving individual signals in a radiation detector output data. The method comprising: obtaining a signal form characterizing the detector; obtaining digitized detector output data in a form of a digital time series; making parameter estimates of one or more parameters of at least one signal present in the detector output data, wherein the one or more parameters comprise at least a signal temporal position of the at least one signal; forming a mathematical model based on the digital time series and as a function of at least the signal form, the temporal position of the at least one signal, and an amplitude of the at least one signal; and determining the amplitude of the at least one signal based on the mathematical model, the amplitude being indicative of a radiation event.

Abstract: A method and apparatus for resolving individual signals in detector output data, the method comprising determining a signal form of signals present in the data, making parameter estimates of one or more parameters of the signals, wherein the one or more parameters comprise at least signal temporal position, and determining the energy of the signals from at least the form and the parameter estimates.