72 results about "Infrasound waves" patented technology

An active non-lethal infrasound system for denying all bird species access to critical areas, particularly in areas around aircraft and other high value systems. The system comprises a plurality of infrasound generators broadcasting continuous infrasonic signals to create a bird-free infrasound active zone within the perimeters of the protected critical area and an infrasound-free dead zones for birds being denied access to the critical areas. Further, an active infrasonic barrier is assembled within an exclusion area surrounding the bird-free infrasound active zone to dampen all low frequency sound waves emanating from the critical area and its perimeters. Wherever the situation allows, a wildlife sanctuary is preferably established further from the exclusion area to attract and protect birds, enforced by broadcasting infrasound signals that simulate natural sounds that attract species typical of the geographic location.

The invention discloses a mud-rock flow early alarm system. The system consists of field monitoring equipment (1), a transmission network (2), a monitoring centre server (3) and a monitoring centre client (4), wherein the field monitoring equipment (1) consists of an intelligent remote measuring rain gauge (11), a mud-rock flow infrasound alarm (12), an ultrasonic mud level meter (13) and image monitoring equipment (14); the monitoring centre server (3) consists of a rainfall information receiving and processing system (31), an infrasound information receiving and processing system (32), a mud level information receiving and processing system (33) and an image receiving and processing system (34); and the monitoring centre client (4) consists of an information display unit (41), a data analysis unit (42) and a threshold configuring unit (43). The mud-rock flow early alarm system integrates rainfall monitoring, mud level monitoring, mud-rock flow infrasound monitoring and image monitoring together, and expresses according to the integration of the information, of rainfall, mud level, infrasound and image, which shows that the mud-rock flow is coming or comes to achieve the effect of signal compensation and comprehensive judgment.

Embodiments of infrasound sensors comprising multiple matched-responsivity pressure sensors are presented. Infrasound sensors in accordance with the present invention have limited volume, which enables them to observe wind velocity at the same point that infrasound is monitored. The small size and matched-responsivities enable infrasound sensors in accordance with the present invention to obviate the need for complex and costly spatial filters that degrade the signal-to-noise ratio of prior-art infrasound sensors.

A horn powered by a compressed air canister and/or battery pack, that emits sounds that are too high for humans to hear (ultrasonic) and/or too low for humans to hear (infrasonic), to act as a means for repelling animals that can hear these sounds (e.g., mammals, birds, reptiles, or insects), combined with a strobe light powered by the battery pack, that can temporarily blind animals. The canister may contain air or other gases. Ultrasonic and infrasonic sounds may alternate. There can be different sound patterns adapted to different species of animals. It may be hand-held and operated by push button or other means. It can also enable lost persons to send signals to rescuers. It may have a strap for carrying, that can be placed around a user's neck. Alternatively, it may have a clip that can be used to attach the device to a belt, back pack, bicycle, etc.

An Atmospheric Turbulence Detector utilizes a sensor to detect noise and extracts infrasound having frequencies below a specified infrasound frequency. A threshold is computed from the detection of infrasound in the vicinity of the sensor prior to the arrival of infrasound from the turbulence and an alarm is given when the infrasound from the turbulence exceeds the computed threshold. Range and direction of atmospheric turbulence are determined with the utilization of two sensors, measuring the phase difference between the detected infrasound of the two sensors, measuring amplitude differences of the infrasound detected at two separate locations.

A system and method for downhole data communication using an infrasound wave generator and receivers. The infrasound waves have a low frequency and a wavelength that is much larger than the transverse dimensions of the well. When the infrasound waves are directed down the well, the well will act as a wave guide for low frequency excitations. The receivers are operatively connected to inflow valves and other downhole equipment, and receive the infrasound waves. If the waves are of a predetermined frequency, the receivers command the valves to open or close, or otherwise control downhole equipment. The infrasound waves can also be used to probe well geometry and to identify fluid properties within the well.

The invention pertains to the sensing and measurement of infrasound (pressure variations with frequency content under 10 Hertz). The invention measures the infrasound pressure variations and then attenuates undesired contributions due to, but not limited to, changes in ambient fluid speed and changes in altitude of the sensing device. The undesired contributions are attenuated using an adaptive filter with the measurements of the change in ambient fluid speed and the change in altitude. This approach differs from existing applications of adaptive filtering in that the invention uses measurements of speed and displacement to improve a pressure measurement. This approach differs from existing methods for attenuating the affects of the wind on the measurement of infrasound in that it does not require the use of a large spatial averaging filter.

An infrasonic stethoscope for monitoring physiological processes of a patient includes a microphone capable of detecting acoustic signals in the audible frequency bandwidth and in the infrasonic bandwidth (0.03 to 1000 Hertz), a body coupler attached to the body at a first opening in the microphone, a flexible tube attached to the body at a second opening in the microphone, and an earpiece attached to the flexible tube. The body coupler is capable of engagement with a patient to transmit sounds from the person, to the microphone and then to the earpiece.

Differential pressure sensor assemblies for detecting and measuring infrasound, which is generally characterized as sound produced at frequencies below 20 Hertz (Hz). Specifically, the differential pressure sensor assemblies may form part of a detection system for clear air turbulence or other atmospheric turbulence. The differential pressure sensor assemblies detect a differential pressure across a flexible diaphragm that separates an ambient pressure chamber from a reference pressure chamber. In one embodiment, the pressure in the reference chamber may be controlled using a valve that may be selectively opened and closed. In another embodiment, the pressure in the reference chamber may be controlled using a static, structural member with a plurality of small openings that permits the reference chamber to be in continuous fluid communication with an ambient environment.

The invention relates to an infrasound sensor array telemetric system of a micro-electronic mechanical system in the telemetric field. A data detecting control system controls a scanning orientation control system; the scanning orientation control system controls an ultralow-frequency sound wave emitting system and a micro-electronic mechanical frequency coupling sensor array and transmits feedback information to a data analyzing system; an ultralow-frequency sound wave bunch emitting system emits detecting sound wave to a geologic structure, and the detecting sound wave passes through the micro-electronic mechanical frequency coupling sensor array; the micro-electronic mechanical frequency coupling sensor array receives low-frequency signals, carries out frequency mixing and coupling for the low-frequency signals, transforms the low-frequency signals into medium-frequency signals; measuring frequency coupling signals are transmitted to an analog-to-digital conversion data transmitting network to carry out analog digital signal conversion; measured data is transmitted to a data analyzing system and a data detecting and controlling system to carry out information exchange; and analyzed data result and the feedback information are transmitted to the data detecting and controlling system. The system has the advantages of fast testing speed, strong response ability and high quality of data transmission.

The invention belongs to the technical field of pipeline leakage detection, in particular to a heat supply pipeline leakage detection system based on infrasound waves and a reference point. The heat supply pipeline leakage detection system comprises a center control system, an upstream acoustic wave monitoring device, a downstream acoustic wave monitoring device and an acoustic source device. Thedistance between the upstream acoustic wave monitoring device and the downstream acoustic wave monitoring device is fixed. The acoustic source device is located on a pipeline between the upstream acoustic wave monitoring device and the downstream acoustic wave monitoring device, and the distance between the acoustic source device and the upstream acoustic wave monitoring device is fixed. The upstream acoustic wave monitoring device, the downstream acoustic wave monitoring device and the acoustic source device are all connected with the center control system through wired network or wireless network for two-way data communication. According to the heat supply pipeline leakage detection system based on the infrasound waves and the reference point, the velocity of acoustic wave propagation inthe pipeline can be measured online by detecting an acoustic wave signal emitted from the reference point, when a pipeline leakage accident occurs, the calculation accuracy of a leakage location canbe significantly improved by calculating the leakage location at the acoustic wave transmission velocity, and the site survey workload of maintenance personnel is greatly reduced.

The invention relates to an ultra-low-frequency abnormal infrasound signal judging method and belongs to the technical field of experimental testing. According to the ultra-low-frequency abnormal infrasound signal judging method, whether abnormal infrasound signals exist or not is analyzed and preliminarily judged through an energy curve according to the characteristics of large time scale, long propagation distances, severe signal distortion, source and background signal complex and the like of ultra-low-frequency infrasound signals produced in natural and artificial events including great pre-earthquakes, tsunamis, air explosion and the like during propagation, and if so, the abnormal infrasound signals of different stations come from the same infrasound event through wide-area multi-point long-time digital discrete correlation analysis. Compared with the prior art, the ultra-low-frequency abnormal infrasound signal judging method can achieve intelligent extraction of specific-frequency-band high-amplitude signals from infrasound monitoring data, decrease the work amount of artificial recognition, provide a quantized basis for judgment on abnormal infrasound signals and conduct quantizing calculation on the correlation degree of the infrasound signals and is used for judging whether ultra-low-frequency infrasound waves come from the same event.

The invention discloses a debris flow forewarning system and a debris flow forewarning method. The system comprises an earth sound monitor, an air infrasound monitor and a telemeter main station. The method comprises the steps that a time difference of an air infrasound signal to the air infrasound monitor and an earth sound signal to the earth sound monitor is obtained according to propagation speeds of the earth sound signal and the air infrasound signal, the telemeter main station starts timing according to earth sound signal forewarning information sent by the earth sound monitor, whether time of the air infrasound signal, sent by the air infrasound monitor, to the telemeter main station is equal to the time difference of the air infrasound signal and the earth sound signal to the monitor or not is judged, the telemeter main station monitors occurrence of debris flow if the time is equal to the time difference, and the telemeter main station monitors as an interference signal if not. The time difference is formed through distribution of an earth sound and an air infrasound in space distance. Debris flow forewarning precision is greatly improved through the time difference to accurately judge an infrasound signal of the debris flow. The debris flow forewarning system and the debris flow forewarning method have a strong anti-inference ability, are capable of forewarning the occurrence of the debris flow accurately and timely, and ensure safety of lives and properties.

A first drone equipped with a high energy Directional Ultrasound Parametric Speaker Array and a second drone equipped with an Acoustic Dispersion Cannon are used to fight wildfire. The first drone is distanced far from a burning flame but in close proximity to a fire target. Both drones are guided by GPS to communicate with remote operators. Once the target is locked, the first drone blasts the target with Amplitude Modulated Ultrasound. The Ultrasound is self-demodulated into a lower frequency audio sound when it encounters a hot flame of richly charged ions. The lowered frequency sound pushes and pulls the flame forward and backward rapidly away from the combustion source, causing it to be disconnected from the flame which instantly cools down and is extinguished. The second drone blasts the combustible source with powerful sonic shockwaves to disperse the still hot particulates further apart to prevent the source being reignited.

The invention relates to an infrasonic sensor comprising a metal shell. A metal wire enclosure is arranged on the inner side of the top end of the metal shell. A tapered resonant disc is arranged under the metal wire enclosure. A piezoelectric chip is arranged under the tapered resonant disc above a chip mounting structure; the chip mounting structure is arranged on a bracket; the bracket is arranged at the bottom of the metal shell; an anode lead terminal and a cathode lead terminal are arranged at the bottom end of the metal shell and provided with an anode lead and a cathode lead respectively; the anode lead and the cathode lead are both connected with the piezoelectric chip. The infrasonic sensor is simple in structure, small in size, high in sensitivity and well responsive to low-frequency infrasound.

The invention relates to an infrasound detection device and method of determining a goaf fire area in a coal field. The device includes an underground semi-space infrasound collecting and amplifying component/assembly, an infrasonic sensor, a preamplifier, a low-pass filter, a data recorder, a computer and a data transmission line. According to the infrasound detection device and method of the invention, ground semi-space signals are shielded through an internally-vacuumized double-layer hemispheric device; underground semi-space infrasound signals are received through the infrasonic sensor connected with the underground semi-space infrasound collecting and amplifying component/assembly; the output signals of the infrasonic sensor are transmitted to the preamplifier through the data transmission line; after being processed by the preamplifier, the signals are transmitted to the low-pass filter through the data transmission line, so that audio signals of which the frequency is higher than 20Hz are filtered out; the filtered signals are transmitted to the data recorder; data in the data recorder are inputted into the computer; and based on software calculation and analysis, the combustion fire area of the coal field can be located. The infrasound detection device has the advantages of simple structure, convenient operation and high detection accuracy.

The invention discloses a dam leakage detection method, which relates to the technical field of water conservancy and hydropower, in particular to a dam leakage detection method. The principle for detecting dam body leakage is based on the fact that when a water body with pressure flows through a crack or a pipeline in a dam wall body, friction is generated with the wall body to generate elastic waves, and the elastic waves with different frequencies and energy are spread upwards along a wall body medium. Because the attenuation of low-frequency elastic waves is small, the low-frequency elastic waves can be propagated upwards for a long distance along a wall body medium. Therefore, the energy of the elastic wave is detected along the trend of the dam body, and the position below the position corresponding to the maximum point is the position of a crack or a pipeline in the wall body. Due to a leakage point direct measurement principle, compared with an electromagnetic measurement principle, direct and accurate positioning can be realized by adopting a mode of detecting elastic waves, and the problem of multiple solutions of results does not exist. The method is suitable for dam leakage detection, especially for detection of low and medium-frequency infrasound waves in the dam.