653 results about "Doppler effect" patented technology

The present invention provides a new non-invasive technique for organ, e.g., heart and lung, monitoring. In at least one embodiment of the invention, a subject is radiated with a non-harmful and relatively low power electromagnetic source diagnostic signal normally associated with a communications protocol such as, but not limited to a version of the IEEE 802.11(x) family of protocols in the 2.4, 3.6, or 5 GHz spectrum bands. After passing through the patient, a return signal is acquired from the patient and compared to the original source signal. The differences between the source and modified signals are then analyzed to monitor the heart, e.g., measure heart rate and detect defects within the heart, and the lung. For example, using Doppler Effect principles, heart rate and motion can be measured from the differences in frequency, phase, and/or wavelength between the source signal and the modified signal reflected back from the heart moving within the patient.

Aspects of the of the disclosure relate to a non-contact physiological motion sensor and a monitor device that can incorporate use of the Doppler effect. A continuous wave of electromagnetic radiation can be transmitted toward one or more subjects and the Doppler-shifted received signals can be digitized and/or processed subsequently to extract information related to the cardiopulmonary motion in the one or more subjects. The extracted information can be used, for example, to determine apneic events and/or to provide apnea therapy to subjects when used in conjunction with an apnea therapy device. In addition, methods of use are disclosed for sway cancellation, realization of cessation of breath, integration with multi-parameter patient monitoring systems, providing positive providing patient identification, or any combination thereof.

Aspects of the of the disclosure relate to a non-contact physiological motion sensor and a monitor device that can incorporate use of the Doppler effect. A continuous wave of electromagnetic radiation can be transmitted toward one or more subjects and the Doppler-shifted received signals can be digitized and/or processed subsequently to extract information related to the cardiopulmonary motion in the one or more subjects. The extracted information can be used, for example, to determine apneic events and/or snoring events and/or to provide apnea or snoring therapy to subjects when used in conjunction with an apnea or snoring therapy device. In addition, methods of use are disclosed for sway cancellation, realization of cessation of breath, integration with multi-parameter patient monitoring systems, providing positive providing patient identification, or any combination thereof.

Seamless hand-off of air-to-ground telephony calls is achieved autonomously within an aircraft by using one of at least two radio links to search for additional ground stations. The search for candidate ground stations for hand-off is expedited by eliminating ground stations exhibiting zero or negative Doppler effects. Other values indicating quality of the link corresponding to the channel over which the search is conducted is compared with the quality of the call and an alternate call is established using the call identification code previously established for the call in progress. The hand-off of the call may then be easily conducted by transferring the voice signal to the channel over which the search was conducted. This is preferably done at a time when the transmission quality of the two channels would be approximately the same or the quality improved on the channel to which hand-off is made.

An aircraft-mounted base transceiver station (mBTS) for providing intermittent coverage in a cellular radio network. The mBTS utilizes the existing protocol of its terrestrial counterparts, thereby avoiding dual-mode devices and enabling common usage of terminal monitoring and device management systems for devices connected to a single radio access network even when outside terrestrial coverage areas. The aircraft follows a transient flight pattern, providing intermittent flyover connectivity for remote radio device such as machine-type devices. Connectivity may be store and forward. Channel usage may be adjusted to avoid interfering with terrestrial communication cells during flyover. Doppler effects due to aircraft speed may be accounted for. The mBTS may be configured to service in-range radio devices which are outside a Doppler-inhibited region and/or to prioritize communication with devices based on expected time outside the Doppler-inhibited region. An aircraft mounted antenna may have a radiation pattern focused toward devices outside the Doppler-inhibited region.

Apparatus for Doppler correction in a wireless communications system, including a first frequency synthesizer for generating a carrier signal oscillating at a rate responsive to a first input, a counter coupled to the first input for generating a Doppler compensation signal, the counter having a clock input, and a second frequency synthesizer coupled to the clock input for generating a clock signal oscillating at a rate responsive to a rate input. The rate input is adjusted over time according to a predetermined sequence so that the Doppler compensation signal compensates for the Doppler effect experienced by, for example, ground-to-satellite communications in a satellite communications system.

Aspects of the of the disclosure relate to a non-contact physiological motion sensor and a monitor device that can incorporate use of the Doppler effect. A continuous wave of electromagnetic radiation can be transmitted toward one or more subjects and the Doppler-shifted received signals can be digitized and/or processed subsequently to extract information related to the cardiopulmonary motion in the one or more subjects. The extracted information can be used, for example, to determine apneic events and/or snoring events and/or to provide apnea or snoring therapy to subjects when used in conjunction with an apnea or snoring therapy device. In addition, methods of use are disclosed for sway cancellation, realization of cessation of breath, integration with multi-parameter patient monitoring systems, providing positive providing patient identification, or any combination thereof.

A mobile terminal (UE) comprises means (CR) for acquiring pseudo-random codes modulating signals received from positioning satellites (SN) in view belonging to a constellation (CS) and related to a reference time, and computation means (MC1-MC3) for determining its position received from the acquired codes and from navigation data contained in the signals. The acquisition means (CR), on receiving assistance data representing an approximate reference time and the approximate position of the terminal (UE), determine estimated positions of the satellites, estimated distances between the terminal and each of the satellites in view and associated Doppler effects as a function of pairs of hypotheses relating to the approximate reference time and the approximate position, and then determine a signal replica for each pair of hypotheses corresponding to the estimated positions and distances and to the associated Doppler effects over a selected time interval, and select the pair of hypotheses corresponding to the signal replica having the maximum correlation with the signal received during the time interval in order to determine the pseudo-random codes modulating the received signals.

A depth measurement system for determining an absolute depth of a drill string uses a position acquisition device to determine a length value for a joint or stand being added to the drill string. The position acquisition device receives a signal from a target object associated with the added joint. The processed signal can be an optical signal, a radio signal, an acoustic signal, or other suitable signal. Using techniques such as time lapse, Doppler effect or phase shift, the depth measurement system determines a position parameter such as distance or position based on the received signal. Thereafter, the processor determines the absolute depth of the drill string by summing a length of each joint making up the drill string and correcting for the position of the newly added joint.

Methods and systems for determining the resonance frequency of a resonator, using the Doppler effect. An interrogating sonic beam including a carrier frequency and one or more resonator exciting frequencies is directed at a resonator disposed in a measurement environment. Resonator vibrations are excited by the resonator exciting frequencies. The carrier frequency is modulated by the vibrating part(s) of the resonator. The returning signal is received and analyzed to determine the amplitude of the Doppler shifted sideband frequencies. The resulting data is processed to determine the resonator's resonance frequency. Using calibrated resonating sensors having a resonance frequency that varies as a function of a physical parameter in a measurement environment, the method and systems allow determining the value of the physical variable from the sensor's resonance frequency. The methods and systems may be used, inter alia, to determine intraluminal blood pressure in various parts of a cardiovascular system, the pressure of intra-cranial fluids, the pressure of fluids in various bodily cavities by using implantable calibratable resonating pressure sensors. The methods and systems may also be used for determining the pressure in various industrial measurement environments and enclosures. Methods and systems are provided for detecting the sensor and for centering the interrogating beam on the sensor.

A system and method for automatically rotating a control knob unit on an appliance or other device to an Off position upon the occurrence of a safety event is provided. The control knob unit may be secured to and engaged with an operational shaft on the appliance which controls the flow of gas or power to the appliance. The system may include one or more detectors (or detector modules) that are configured to emit a signal upon an occurrence of the event, such as a fire, which may be an early indication of a developing emergency. The signal may be in the form of an audible alert, such as sound (or sound waves). A data transceiver processing module may receive a plurality of sound waves and analyze the plurality of sound waves for a variation in frequency (or Doppler Effect) to determine if any of the sound waves originate from the one or more detector modules.

The invention relates to determining a correct code phase of a received, code modulated carrier signal using a correlation portion, a frequency compensation portion, a coherent memory and a non-coherent memory. In order to compensate for a code Doppler effect and/or a carrier Doppler drift effect, a mapping portion maps correlation values either to the coherent memory or to the non-coherent memory. Alternatively, the mapping portion maps correlation values stored in the coherent memory or in the non-coherent memory to new positions. The mapping depends on a frequency compensation applied by the frequency compensation portion and elapsed integration time, and/or on a drift of a frequency offset in correlation values output by said correlation portion.

The invention discloses an onboard automatic speed measuring and height measuring radar system and a speed measuring and height measuring method. The system comprises an antenna, a transmitter, a superhet receiver, a broadband digital intermediate-frequency receiver, a center computer and a power module. The transmitter generates four sawtooth wave linear frequency modulation radio-frequency signals and achieves space symmetric configuration through the antenna; the superhet receiver and the broadband digital intermediate-frequency receiver complete echo signal digital demodulation together and calculate the frequency, amplitude, phase and signal-to-noise ratio information of echo signals; the center computer separates the speed information and the height information of the same echo beam by applying Doppler principle directivity based on the space symmetry and the timing sequence relevance of four beams, and the information is used for calculating the flight speed value and the flight height value of an aircraft. According to the onboard automatic speed measuring and height measuring radar system and the speed measuring and height measuring method, the same radar can be used for automatically measuring the speed and the height, the structure of an aircraft avionics system is simplified, the measuring precision is high, and the onboard automatic speed measuring and height measuring radar system and the speed measuring and height measuring method can be used for measuring carrier aircraft flight parameters.

A piezoelectric thin film sensor array is used to scan and capture biometric data, for example, a fingerprint image. In one embodiment, a multi-layer structure includes a PVDF layer in between two conductor grids arranged orthogonally to one another. Urethane can be added to one side where a finger is placed. A foam substrate can be used as a support. In one feature, the PVDF, and grids can be peeled off like a label for easy replacement. Multiplexers are switched to scan the sensor. A single pixel or a group of pixels can be detected and output to an image memory. The presence of a fingerprint ridge is detected by virtue of a ring-down oscillation that arises from reflection when an electric field is applied to the piezoelectric thin film sensor array at a pixel in contact with the fingerprint ridge. For example, such a ring-down value associated with a fingerprint ridge can be detected at about 150 ns. (or 5 cycles at 30 MHZ). Other reflections indicative of additional biometrics (e.g. from tissue, blood, bone, fingernail, etc.) can also be detected. A Doppler effect due to reflections from circulating blood can also be detected. Such a Doppler effect can provide further information about direction and speed of blood circulation. An instantaneous pyroelectric effect can also be detected to indicate a live finger presence.

The invention discloses a Doppler radar-based non-contact type vibration measuring method. The method includes the following steps: S1. directly facing a measured vibration object to emit single-frequency microwaves in the form of continuous waves, and receiving radar echoes after modulation by vibration motion; S2. performing amplifying, filtering and quadrature mixing on echo signals and taking down conversion signals to obtain two paths of baseband signals I(t) and Q(t); S3. performing data collection on the baseband signals to obtain discrete digital signals; and S4. performing phase demodulation processing on the discrete baseband signal I[n] and Q[n], and extracting vibration amplitude and frequency information. The Doppler radar-based non-contact type vibration measuring method provided by the invention uses a microwave radar to perform non-contact type vibration measurement based on a Doppler effect, has good low frequency measurement sensitivity, is high in environmental adaptation, and can perform accurate vibration measurement under the condition of containing a barrier. The microwave radar used by the method is compact in structure and low in cost and has relatively low power consumption, thereby providing a solution to integration of a large-scale vibration measuring system.

The invention discloses a Doppler factor estimation and compensation method of mobile underwater acoustic communication, related to underwater acoustic communication. The Doppler factor estimation andcompensation method of the mobile underwater acoustic communication comprises the following steps: 1) large scale Doppler estimation and compensation; 2) residual Doppler estimation and compensation;and 3) Doppler phase rotation compensation. In order to accurately and efficiently estimate the Doppler factor in the mobile underwater acoustic communication environment, overcome the more obvious Doppler effect compared with the terrestrial radio channel and eliminate the adverse effects on the underwater acoustic OFDM communication system of the Doppler effect, a Doppler factor estimation andcompensation method of the mobile underwater acoustic communication considering both the accuracy and the computationcomplexity is needed. Because the estimation is carried out in the frequency domainand aims at the characteristics of the underwater acoustic channel, the Doppler factor estimation and compensation method of the mobile underwater acoustic communication, especially the Doppler factor estimation and compensation method applied to the mobile underwater acoustic OFDM system is more suitable for the fast changing mobile underwater acoustic channel based on the traditional Doppler estimation and compensation. The estimation accuracy is high; and meanwhile, the computation complexity is reduced appropriately, therefore, the practicability is excellent.

The invention concerns a passive radar receiver for a received orthogonal frequency division multiplex-type signal consisting of symbol frames each emitted on coded orthogonal carriers. After formatting the received signals into digital symbols (S₁ S₁), a filtering circuit (2) eliminates by subtraction or using a covariance matrix, in the symbol signal at least unwanted signals with null Doppler effect so as to apply a filtered signal (X′) including essentially signals backscattered by mobile targets to a Doppler-distance correlator (4).

A method for re-establishing a moving sound source by adopting a moving equivalent source method is characterized in that the method comprises the following steps of measuring Doppler effect-contained sound pressure data in a moving sound source radiation sound field; establishing a transmission relationship between vibration speed and radiation sound pressure under Doppler effect-contained measured sound pressure and sound source static situation by the moving equivalent source; removing the influence of the Doppler effect according to the transmission relationship; and realizing the positioning identification and sound field re-establishment of the moving sound source. The moving sound source applicable to the method can be any shapes including plane, cylindrical surface or spherical surface; and the method is developed on the basis of a near-field acoustical holography reconstruction algorithm based on the equivalent source, has good computation stability, high computation precision and simple execution.

The invention provides a two-degree-of-freedom heterodyne grating interferometer displacement measurement system and method. The system comprises a double-frequency laser device, a grating interferometer, a measuring grating, a receiver and a signal processing unit. The grating interferometer comprises a lateral displacement light splitting prism, a polarization light splitting prism, a 1/4 wave plate, a reflecting mirror and an optical fiber coupler. The method realizes displacement measurement based on grating diffraction, the optical Doppler effect and the optical-beat frequency principle. Laser of the double-frequency laser device is incident to the interferometer and the measuring grating and then optical signals are outputted to the signal processing unit. When the interferometer and the measuring grating perform two-degree-of-freedom linear relative movement, the system can output two linear displacements; the measurement system adopts Littrow incident conditions, a measurement target has large passive movement tolerance and two linear displacements can be measured simultaneously so that precision can reach the nanoscale and higher scale; and the measurement system has advantages of short light path, small size, compact structure, low weight and low requirement for the measuring grating and is suitable for two-degree-of-freedom high-precision long-stroke displacement measurement.

An ultrasonic diagnostic apparatus in which an image generation time can be reduced and a frame rate can be improved even in a color mode in which a two-dimensional color Doppler image obtained due to Doppler effect is combined with a B-mode image. The ultrasonic diagnostic apparatus includes an ultrasonic probe, a transmission system signal processing unit for supplying drive signals to the ultrasonic probe to transmit pulse trains, each including plural pulses respectively having frequency components of orthogonal frequency division multiplexing waves orthogonal to one another and having different center frequencies from one another, in the same direction, and a reception system signal processing unit for pulse-compressing the plural pulses having different frequency components included in each reception signal outputted from the ultrasonic probe which has received the pulse trains from the same direction, and generating a B-mode image signal based on the compressed pulse.

In a vehicle-to-vehicle network, a driver may listen to audio generated by other drivers participating in the network. The usability of the audio is enhanced by determining the relative positions of the providing and the receiving vehicles and then distributing received audio to specific speakers in the audio system of the receiving vehicle to create an impression that the sound originates from a source on the line between the two vehicles. The audio distributed to different speakers in the vehicle changes as the relative positions of the two vehicles changes. Volume changes and Doppler effects can be added to the audio if the two vehicles are converging or diverging.

The invention provides a pulsar navigation method with a single detector, which comprises the steps that an X-ray detector on a spacecraft receives X-ray photons from four millisecond pulsars one by one and measures times when the X-ray photons arrive at the X-ray detector; the arrival times are saved as original observation signals; a doppler effect, a relativistic effect and Shapiro delay correction are performed; the arrival time of a pulse profile datum point is obtained; an observation equation of each corresponding pulsar is formed; and independent timing and positioning of the spacecraft are realized after resolving. The pulsar navigation method can accomplish absolute positioning of the pulsars with the single detector, and the positioning accuracy is high without secular error accumulation.

A method includes: receiving, at a host vehicle, a plurality of messages transmitted using Vehicle-to-Vehicle (V2V) communications indicating a heading angle and a speed of a remote vehicle; calculating an expected change in frequency of the plurality of messages received at the host vehicle based on the heading angle and the speed of the remote vehicle; measuring an actual change in frequency of the plurality of messages received at the host vehicle due to the Doppler effect; comparing the expected change in frequency to the actual change in frequency; and determining that the plurality of messages were not transmitted from the remote vehicle when a difference between the expected change in frequency and the actual change in frequency exceeds a predefined frequency change threshold.

The invention discloses a multi-laser-beam heterodyne micro-impulse-measuring device and a multi-laser-beam heterodyne micro-impulse-measuring method and relates to the technical field of micro impulse detection. By the device and the method, the problems of low energy coupling efficiency and big system error in the current small-impulse-measuring system are solved and the micro impulse measurement is carried out on the basis of a laser heterodyne technology and a Doppler effect. The method comprises the steps of: converting the micro impulse generated under the action of the laser and a target into a rotating angle of a torsional pendulum; then introducing a scanner into the measuring light path to attach an optical frequency to each of the light signals entering at different time points, so that a reflected light from the front surface of a planer standard lens and a transmitted light reflected by the front surface and the back surface of the planer standard lens for many times generate a multi-beam heterodyne interfering signal under an interfering condition; and thus modulating the change information of the rotating angle of a standard beam into the frequency difference of a medium-frequency heterodyne signal successfully. With polyvinyl chloride (PVC) and 2 percent of carbon (C) as working fluid, the micro impulse generated under the action of the laser and the working fluid is simulatively measured by using a torsional pendulum method and the measurement result shows that the maximum relative error of the measurement is less than 2.3 percent.