813 results about "Direct wave" patented technology

A method is described for the measurement of multidirectional far-field source signatures from seismic surveys whereby a vertical cable acquisition technique is provided, vertical cable data are acquired, the proper receivers are specified to measure the signature, data are sorted into common selected receiver gathers CSRG, the direct wave within common receiver gather is properly windowed, the angles of each direct path are computed and the amplitude of the signatures is normalized, so as to obtain the multidirectional far-field signatures of the seismic source array having the same characteristics as those that generated the seismic reflections.

Geophysical exploration for oil wells, the source from the vertical seismic profile aspect wave data stack depth domain Corridor profile approach is the use of in situ collection of well spacing VSP data, which will all receive points drilling depth of information and hierarchical data with the depth of information, the use of direct wave VSP data travel through and optimization algorithms are highly accurate anti-layer velocity model, the direct wave to the beginning of the reflected wave in the vicinity of the depth and precision homing imaging, further in-depth domain Corridor section and with the superposition of alternative conventional method leveled in the time domain, with corridors and the superposition method, the results can be superimposed for direct comparison with the drilling and seismic data stratified layer identification. More intuitive, but also made full use of VSP data in the depth of information, make geological formation of the earthquake response and drilling, logging data in depth domain direct contrast, a more intuitive geological layer and the relationship between seismic horizon, thereby enabling layer of identification and calibration more reliable.

A method and apparatus for enhancing the moveout between a direct wave and a reflected wave. The method involves transmitting imaging signals into a body to be imaged and receiving the resulting signals propagated from the signal source. The step of receiving the propagated signals includes selectively adjusting the distance between the signal source and the signal receivers between successive signals. The method further comprises separating the reflected signals from the total received signals and enhanced stacking of the measured reflected signals.

A MIMO communication system having deterministic channels the orthogonality of which can be ensured even if a reflected wave other than the direct wave is present during line-of-sight communication is provided. The MIMO communication system is used in a line-of-sight environment and has deterministic channels between the transmission side where a plurality of transmission antennas are arranged and the reception side where a plurality of reception antennas are arranged. The transmission side, the reception side, or both transmission and reception sides of the MIMO communication system have a channel matrix calculation processing means for calculating a channel matrix for establishing an orthogonal channel as a communication channel. The transmission and reception antennas forming the channel matrix are horizontally arranged with respect to the ground.

The invention discloses a method suitable for positioning a hydraulic fracturing micro-seismic source. The method includes: building a micro-seismic-monitoring observation system, acquiring logging information and other seismic data, building an initial speed model, researching and analyzing regional stratum conditions and perforation records, determining background interference and micro-seismic signal features, performing noise compression on fracturing records and performing effective waveform identification on micro-seismic signals, and using methods such as first break picking and manual intervention to pick the first break travel time of a direct wave, wherein the travel time of the perforation records is used for optimizing the speed model, and other effective events are used for the inversion positioning of the seismic source. The method has the advantages that transverse wave travel time is added on the basis that longitudinal wave travel time is used, the micro-seismic source is positioned by using the longitudinal wave travel time and the transverse wave travel time to perform simultaneous constraining, the inversion uses a method combining global searching and local searching, and the method is high in positioning precision and high in calculation efficiency.

It is a ultra-wide band earth-probing radar self object identification method based on information integration, which is the following: first to use the large time lag in the relative object signals to the direct wave in the echo-signal of the earth-probing radar and to filter the direct wave; to use the bandwidth relative process to filter wave and to extract typical data and to improve the signal to noise ratio of the signal and to extract the longitudinal and transverse typical data to object shape identification and to extract typical echo-duct data for Welch power spectrum valuation; to use RBF web to classify the object material and finally to integrate the results of the object shape identification and material identification to achieve the complete and effective automatic identification of the underground object of different materials.

The invention discloses a super-resolution height measuring method based on topographic matching for a digital array meter wave radar, which is mainly used for solving the problem of high height measuring error of a fluctuating position in the prior art. The method comprises the following implementation steps of: performing clutter cancellation and interference cancellation processing on a targetsignal received by the radar to obtain a cancelled target signal; roughly measuring a target elevation angle by using a beam forming method; determining a maximum likelihood search range according tothe roughly-measured elevation angle and searching in the search range; computing a ground reflection point coordinate corresponding to each array element and a direct wave path and a reflection wavepath of each target relative to each array element according to a search elevation angle; computing a corresponding direct steering vector and a multipath steering vector by using the direct wave path and the reflection wave path; constructing a synthetic steering vector and computing a projection matrix of the synthetic steering vector; and performing maximum likelihood estimation to obtain a target accurate elevation angle. In the method, an altitude parameter of a radar position and the synthetic steering vector are introduced into super-resolution height measurement, so that the measuringaccuracy is increased; and the method can be applied to target tracking.

Methods and related systems are described for processing surface seismic data. Surface seismic data representing seismic signals detected at a plurality of surface locations is wavefield deconvolved using a combination of direct wave travel times estimated from borehole seismic data, and wavefield energy estimated from the surface seismic data.

A directional sound wave logging while drilling device comprises a drill collar special for the directional sound wave logging while drilling device and a directional sound wave while drilling sonic system installed on a drill collar upper centralizer and composed of a single-transmitting four-receiving probe, and adopts a groovy sound insulator on the drill collar to inhibit drill collar direct waves from a transmitting probe to a receiving probe, wherein the transmitting probe and the receiving probe are respectively powered on by a special power supply battery. A measurement and control circuit receives acquired waveform data to perform real-time calculation treatment, communication interfaces are provided for a measurement while drilling system (MWD) and a ground processing system, the power supply battery and the measurement and control circuit are arranged in a compression resistance barrel in a special drill collar mud flowing channel special for sound waves, and upper and lower flow guiding sleeves are connected with the sonic system. The stratum rock longitudinal and transverse sound velocity measured in the drilling process in real time can be used for lithological identification, porosity degree calculation, rock mechanical parameters, well opening stability prediction and the like.

Disclosed herein is a wireless transmission system. Transmission antennas are provided on a first communication apparatus while reception antennas individually corresponding to the transmission antennas are provided on a corresponding second communication apparatus. Each reception antenna receives a desired wave from a corresponding transmission antenna as a direct wave and receives an unnecessary wave from a different transmission antenna as a direct wave. The first communication apparatus modulates only the amplitude of a carrier signal for all channels. The second communication apparatus demodulates composite waves of desired waves and unnecessary waves received by the reception antennas by envelope detection or square-law detection and carries out correction operation for the demodulation signals based on transmission characteristics of transmission spaces between the transmission and reception antennas to acquire transmission subject signals.

The invention which discloses a radar remote sensing method for detecting the distribution of the water content in soil in a depth direction relates to the radar remote sensing detection technology. The method comprises the following steps: 1, respectively adopting two modes of horizontal polarization and vertical polarization to measure the scattering field of the soil under multiple visual angle and multiple frequency observation; 2, filtering out components of direct waves in radar echoes; 3, scaling echo data; and 4, utilizing the scattering model and the dielectric constant of the soil to obtain the distribution of the water content in the soil in the depth direction. The radar remote sensing method for detecting the distribution of the water content in the soil in the depth direction of the invention allows the distribution of the water content in soil with the depth under the soil surface of 0-3m to be detected, and can be applied to ground, air and space base remote sensing monitoring platforms.

A method of processing seismic data obtained using a seismic vibrator that includes estimating travel times of direct wave arrivals between the seismic vibrator and an array of seismic receiver locations and wavefield deconvolving the seismic data using the direct wave arrival travel times. Also a related method of producing a high-frequency geological subsurface image that includes acquiring seismic data having significant harmonic energy using a seismic vibrator, estimating direct wave arrival travel times between the seismic vibrator and an array of seismic receiver locations, wavefield deconvolving the seismic data using the estimated direct wave arrival travel times, and using the wavefield deconvolved seismic data to produce a high-frequency geological subsurface image. A further related computer useable medium having computer readable program code means embodied therein practicing the inventive method.

The invention discloses a exploration method for transmitting and receiving dipole transverse waves in a well. The remote exploration method comprises the following steps of: setting a sub dipole sound source in the well; controlling the frequency of a dipole sound wave excited by the sub dipole sound source so as to enable a dipole sound source to transmit the dipole sound wave in the well below a bending wave cut-off frequency; filtering received waveform signals of a direct wave in the well and a reflected wave outside the well through a filter; adjusting the signals through programmable gain controlled by a micro-processor and a receiving control system to an amplitude suitable for a subsequent analogue/digital converter; after digitally sampling the signals through the analogue/digital converter, transmitting the signals to the micro-processor; and storing digitized data by the processor and transmitting the digitized data to a ground acquisition system. The technical problem of difficulty in measurement and processing because sound wave signals of a receiver reflected to the well are very weak in the traditional dipole transverse wave method can be solved by the method disclosed by the invention.

Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.

The invention discloses a method for fast realizing the signal processing of passive radar based on a GPU (Graphics Processing Unit). The method comprises the following steps of at a link of direct wave and clutter suppression, dividing whole data into N data blocks and dividing the data blocks into L data segments, wherein the number of data points within each data segment is M; splicing the data with the same data segment number, of each data block together in a way that the current segment of the No. N data block is spliced with the next segment of the first data block; enabling M*N threads by the GPU for parallel processing; at a link of coherent accumulation and walk correction, segmenting the data in a way that all the data are divided into n segments; grouping the continuous segments in a way that every DIM segments form one group; splicing the all groups of data together in sequence and storing such data in a continuous address space of a GPU video memory; and finally, carrying out GPU parallel processing on the each group of data. The method for fast realizing the signal processing of the passive radar based on the GPU is more applicable for the GPU parallel processing, and the higher speedup ratio can enable real-time processing demands to be met.

The invention discloses a single-station user terminal locating method and a system. The method comprises that position information of a plurality of known points in a community is obtained, the position information comprises a signal reaching angle, time advance and longitude and latitude information; information of the signal reaching angle and the time advance of a point to be located is obtained; at least one known point with the signal reaching angle and the time advance most approximate to the signal reaching angle and the time advance of the point to be located is found according to the position information of the known point; and the longitude and latitude information of the point to be located is calculated according to the longitude and latitude information of at least one found known point. According to the single-station user terminal locating method, at least one known point near to the point to be located is found, and longitude and latitude of the point to be located are calculated through the longitude and latitude of at least one known point. The single-station user terminal locating method can solve the problem that a traditional locating method is not accurate caused by multi-diameter or non-direct waves, and can locate accurately under the condition of many obstacles including buildings and the like.