Abstract: A phase difference delay control system is provided that enables distance measurement between a reference position and a terminal at the time of recovery after a line has been disconnected as a result of fluctuation of phase difference of clock crossover units.

Abstract: A continuous environmental noise level recording and analysis system is provided. The system is capable of sampling, processing and storing Equivalent Sound Level values over a period of about two weeks. The recorded data is downloaded and analyzed to show graphs, and to automatically detect noise events of interest.

Abstract: Adaptive noise reduction techniques used in devices that pass light from a laser through a quantum medium such as a rubidium vapor cell. A CPT frequency standard that employs the techniques has a first channel in which the laser light passes through the quantum medium and to a photodetector to produce a first signal and a second channel in which the light passes to a second photodetector without passing through the quantum medium to produce a second signal. The first and second signals are processed in a signal processor to produce an enhanced output signal in which the noise has been reduced. The signal processor implements noise predictor and noise remover. In a preferred embodiment, the noise predictor employs a FIR filter in which the coefficients are set in response to feedback from the enhanced output signal.

Abstract: An apparatus for analyzing the broadband noise content of a digital image comprising the following: a means of automatically identifying regions of originally constant color in the image by analysis of the variance of pixel values of regions of the image; a means of automatically detecting and discarding regions deemed to be unrepresentative of the true noise content of an image, including under- and over-exposed regions; a means of allowing the user to manually select some or all required constant color regions if desired; and, a means of analyzing such constant color regions to generate a parametric or non-parametric model of the noise in the image, including frequency characteristic within and between channels and other characteristics such as phase which might describe structured noise.

Abstract: The weight detecting apparatus includes a weight detecting load cell having a fixed end fixed to a fixed base arranged on a floor and a free end bearing a weight of an object, a first vibration detecting load cell arranged on the fixed end side of the weight detecting load cell for detecting a vibration component on the fixed end side, i.e., a floor vibration component, and a second vibration detecting load cell arranged on the free end side of the weight detecting load cell for detecting a motor vibration component on the free end side, i.e., the motor vibration component. The weight detecting apparatus precisely detects the weight of the object by removing the vibration component from the detection signal of the weight detecting load cell based on the detection signals of the respective load cells.

Abstract: An image processing system includes an image collector and a light falloff correction system. The light falloff correction system comprises a polar transformer that converts an image into radial traces and a falloff fitter that fits the radial traces to a model of falloff to determine a light falloff correction for the image.

Abstract: A technique for estimating the position of an object from sensor measurements in the presence of multipath conditions is disclosed. In one aspect, the technique includes a position estimator comprising a signal filter, a multipath detector, and a multipath bias estimator. The signal filter is capable of receiving a sensor measurement and generating a measurement noise variance estimate and a position estimate therefrom. The multipath detector is capable of applying a dynamic threshold against the measurement noise variance estimate to determine whether a multipath condition exists. And, the multipath bias estimator is capable of generating a correction for multipath induced measurement bias error from a measurement noise variance estimate for application upon determining that a multipath condition exists.

Abstract: A chromatographic analyzer is provided for facilitating curve fitting by means of the linear least-square method for a chromatogram that contains a plurality of overlapping peaks. A chromatographic data processor executes fitting processing to each peak in an arbitrary time region having the plurality of peaks of the chromatogram starting from the front side or back of the time region, and the processed peaks are subtracted from the chromatogram in the time region so that the plurality of peaks in the chromatogram can be separated from one another.

Abstract: A circuit that provides the root-mean-square (RMS) value of an input signal and that detects and independently recovers from an output fault condition is provided. The circuit includes reconfigurable circuitry that changes from normal operating mode to fault recovery mode when an output fault is detected. During fault recovery mode, the circuit provides a modified output signal that allows independent recovery from an output fault condition. Once recovery is complete, the circuit returns to normal operating mode and provides a DC output signal proportional to the RMS value of an AC input signal.

Abstract: A continuous environmental noise level recording and analysis system is provided. The system is capable of sampling, processing and storing Equivalent Sound Level values over a period of about two weeks. The recorded data is downloaded and analyzed to show graphs, and to automatically detect noise events of interest.

Abstract: A system and method for characterizing, synthesizing, and/or canceling out acoustic signals from inanimate sound sources is disclosed. Propagating wave electromagnetic sensors monitor excitation sources in sound producing systems, such as machines, musical instruments, and various other structures. Acoustical output from these sound producing systems is also monitored. From such information, a transfer function characterizing the sound producing system is generated. From the transfer function, acoustical output from the sound producing system may be synthesized or canceled. The methods disclosed enable accurate calculation of matched transfer functions relating specific excitations to specific acoustical outputs. Knowledge of such signals and functions can be used to effect various sound replication, sound source identification, and sound cancellation applications.

Abstract: A method of processing data representing intensity values of a measurement signal as a function of a discrete variable such as time, which signal being characterized by series of peaks mixed with a substantially regular background noise, provides efficient noise attenuation and peak detection capabilities. When applied to a two-dimensional system, the method comprises an initial step of forming an intensity histogram vector representing a frequency distribution from the intensity values, which intensity histogram vector having N frequency vector components associated with corresponding N intensity sub-ranges within a maximum range extending from a minimum intensity value to a maximum intensity value. This initial step is followed by a step of zeroing a portion of the data corresponding to the intensity values which are below an intensity threshold value derived from shape characteristics of the distribution.

Abstract: The system and method for calibrating a signal detection threshold circuit is used in a radio frequency (RF) receiver, such as a in an early warning radar (EWR) system, in which a signal detection threshold circuit rejects signals below a predetermined threshold setting and prevents noise signals from causing false alarms. The system and method include setting an initial threshold setting and receiving noise signals in one or more channels. A threshold comparison circuit rejects noise signals below the threshold setting, and a pulse repetition frequency (PRF) detection circuit detects noise pulses above the threshold setting and determines the PRF. An automatic threshold determiner and setter determines whether the PRF has reached a predetermined frequency (e.g., 400 kHz) and lowers the threshold setting until the predetermined frequency is reached. When the predetermined frequency is reached the threshold setting is stored as a noise measurement.

Abstract: Digital filters are used to compensate for echoes in a transmission system in which unwanted couplings occur between a signal value in the receiving direction and a signal value in the transmitting direction. The correct adjustment of the filter coefficients has a considerable influence on the achievable echo compensation. Disturbance signals such as background noises, nonlinear effects in A/D converters or an active local speaker can briefly change the adjustment of the filter coefficients in a way so that the digital filter does not compensate for the echoes and causes additional echoes in unfavorable cases. In accordance with the invention a set of filter coefficients (C(j)) are weighted with an envelope curve (H(j)) and an error measurement (F(j)) is determined therefrom. Depending on the magnitude of the error measurement (F(j)), the filter coefficients (ci) are used for further processing or are discarded.

Abstract: A device for determining the quality of an output signal to be generated by a signal processing circuit with respect to a reference signal. The device is provided with a first series circuit for receiving the output signal and a second series circuit for receiving the reference signal. The device generates an objective quality signal through a combining circuit which is coupled to the two series circuits. Poor correlation between the objective quality and subjective quality signals, the latter which will be assessed by human observers, can be considerably improved by a differential arrangement present in the combining circuit. This arrangement determines a difference between the two series circuit signals and reduces this difference by a certain value, preferably one that is a function of a series circuit signal. Poor correlation can be improved further by disposing a scaling circuit, between the two series circuits, for scaling at least one series circuit signal.

Abstract: A method employed in a condition monitoring unit (CMU) for monitoring a circuit breaker or interrupter to obtain a substantially undistorted version of a waveform suffering from saturation distortion comprises employing a current transformer (CT) to measure a current waveform. The output of the CT is prone to be a partially distorted waveform. The invention is generic in the sense that it does not require parameters associated with the CT characteristics or with the burden impedance on the secondary side of the CT. A digital representation of the partially distorted waveform is obtained, and then undistorted portions of the partially distorted waveform are identified by comparing the amplitude of the partially distorted waveform within a sliding window to a pair of boundary values and identifying as undistorted those portions having an amplitude between the boundary values. Next, distorted portions of the waveform are separated from the undistorted portions, thereby yielding a data record with holes.

Abstract: A system involving method and apparatus for cancelling a periodic electrical interference signal from a signal of interest is disclosed. The system of the invention creates an estimate of the periodic noise component in an electrical signal by sampling the electrical signal at intervals locked to the period of the source of the electrical interference signal. The system analyzes the sampled signal to isolate periodically repeating portions of the signal characteristic of noise. The system inverts the estimate of the noise component and constructs a continuous repeating waveform which is added to the electrical signal. The system does not eliminate transient features of the signal of interest, even when those transient features have frequency components which overlap with frequencies present in the electrical interference signal.

Abstract: The device for extracting a useful acoustic signal from a composite acoustic signal including nuisance components includes: first sensor component for picking up the composite acoustic signal; second sensor component for picking up, in real-time, the reference acoustic signal, which is substantially correlated with the nuisance components of the composite acoustic signal; adaptive filtering component; and extraction component. The coefficients of the filtering component are adapted in real time according to an algorithm chosen so as to minimize the energy of the composite acoustic signal as a function of the energy of the reference acoustic signal, until the signal leaving the output of the extraction component corresponds substantially to the useful acoustic signal selectively rid of the nuisance components.

Abstract: A novel method of non-harmonic analysis of a physical waveform is disclosed. A digitized wave data is multiplied by a first sine and a first cosine function having a first predetermined period, respectively, and the resulting products are respectively summed over a predetermined interval equal to an integer multiple of the first predetermined period. The resulting summation values are used to determine the amplitudes of the first sine and first cosine functions. A sine and a cosine waveform having the thus determined amplitudes and the first predetermined period are subtracted from the wave data to derive a residual wave data. The above steps are performed on the wave data successively using a second to n-th sine and cosine functions having a second to n-th predetermined periods to derive (n-1) residual wave data. The power of each residual wave data is checked to determine as a first non-harmonic frequency component the sine and cosine waveforms providing a minimum power.

Abstract: A hybrid active-passive system (20) for reducing noise within a passenger compartment and vibration of a fuselage of a vehicle, such as an aircraft (turboprop, turbofan, or helicopter). The hybrid active-passive system (20) includes, in combination: an active acoustic producer such as a loudspeaker (35), Active Vibration Absorber (AVA) (34), or active absorber assembly (39) for producing antinoise within the compartment (42), and a passive resonant device, such as a passive Tuned Vibration Absorber (TVA) (36), or passive TVA assembly (37) for controlling vibration of the fuselage or structural supports interconnecting the disturbance source (e.g. power plants (26), propellers (28a), gearbox (57), main rotor (28m), tail rotor (28t)) and the fuselage wall (25).

Abstract: The invention described herein provides for an intelligent or "adaptable" filtering method that could be applied when filtering log data. In the present invention, for a given filter model, the adaptive filtering technique differentiates between true changes in the formation or borehole quantity measured and what can be considered to be just a "statistical fluctuation". So, when in long constant-value intervals (data deviations do not exceed those predicted by statistical theory) the filter will automatically increase the number of filter levels used, thereby providing a large reduction (smoothing) of the statistical variations. However, when approaching a spot where there is a true change in the quantity being measured (data deviations over and above those predicted by statistics) the filter will automatically and smoothly decrease, on both sides of this spot, thereby preserving the sharpness of the bed boundary or borehole fluid contact and also preserving the true shape of a thin geologic bed.