103 results about "Spectral processing" patented technology

The embodiment of the invention discloses a passive optical network system and a downlink transmission method thereof. The passive optical network system comprises an optical line terminal, an optical distribution network and a plurality of optical network units. The optical line terminal is used to send a downlink multi-wavelength optical signal composed of a plurality of downlink optical signal wavelength division multiplexing having different wavelengths, and the optical distribution network comprises a first-stage optical splitter, a plurality of second-stage optical splitters and a plurality of filter modules. The first-stage optical splitter is used to divide a downlink multi-wavelength signal sent by the optical line terminal into a plurality of downlink multi-wavelength signals, the plurality of filter modules are used to carry out filter processing on the plurality of downlink multi-wavelength signals to obtain a downlink single wavelength optical signal of which the wavelength corresponds to a channel central wavelength; wherein, the channel central wavelengths of the plurality of filter modules respectively correspond to the plurality of downlink optical signals having different wavelengths, the second-stage optical splitters are used to carry out spectral processing on the downlink single wavelength signal and then provide the downlink single wavelength signal to the optical network unit.

An optical network includes a multidimensional coder and modulator for handling multiple-in-multiple-out MIMO spatial lightpath properties and content of any specific supercarrier, a spatial mode multiplexer responsive to orthogonal frequency division multiplexing OFDM transmissions and the multidimensional coder, a spatial-spectral routing node coupled over a fiber link to the spatial mode multiplexer for performing switching granularity by a spatial mode reconnection, a multidimensional decoder and demodulator; and a spatial mode demultiplexer coupled over a fiber link to the spatial-spectral routing node and responsive to the multidimensional decoder and demodulator.

A method of multi-spectral opto-acoustic tomography (MSOT) imaging of a target tissue including a target tissue biomarker comprises the steps of illuminating the target tissue with an illumination device emitting at least one pulsed illumination pattern at several illumination wavelengths, detecting pressure signals from the target tissue biomarker with a detector device, wherein the pressure signals being produced in the target tissue in response to the said illumination, and reconstructing a quantitative tomographic image of a distribution of the target tissue biomarker in the target tissue, wherein the pressure signals are analyzed using a photon propagation model, which depends on an illuminating light fluence in the target tissue and on the illumination wavelengths, at least one spectral processing scheme, and an inversion scheme providing the tomographic image. Furthermore, an imaging device for multi-spectral opto-acoustic tomography is described.

An inversion-based algorithm for computing the time frequency analysis of reflection seismograms using constrained least-squares spectral analysis is formulated and applied to modeled seismic waveforms and real seismic data. The Fourier series coefficients are computed as a function of time directly by inverting a basis of truncated sinusoidal kernels for a moving time window. Spectra may be provided that have reduced window smearing for a given window length relative to the discrete Fourier transform irrespective of window shape, and a time-frequency analysis with a combination of time and frequency resolution that is superior to the short time Fourier transform and the continuous wavelet transform. The reduction in spectral smoothing enables enhanced determination of spectral characteristics of interfering reflections within a short window. The degree of resolution improvement relative to the short time Fourier transform increases as window length decreases.

The invention relates to an automobile anti-collision alarm system based on pulse laser ranging, which belongs to the technical field of electronics, which is provided with a control circuit, a laser transmitting circuit, a laser receiving amplifier circuit and relevant circuits. A single chip microcomputer STC12C5A60S2 is the core of the control circuit, after laser pulse signals are in spectral processing by a spectroscope with the support of corresponding programs, one channel of the laser pulse signals is reflected by a reflector to be directly received by a PIN receiving circuit, another channel of the pulse laser signals is reflected by an automobile ahead, and then is received by the APD (avalanche photo diode) laser receiving circuit, after receiving time of each of the channels of the laser pulse signals is accurately corrected by a discriminator circuit, the channels of the laser pulse signals are transmitted to the single chip microcomputer master control circuit to be processed, the distance from an automobile with the automobile anti-collision alarm system and the automobile ahead is monitored in real time, and the system can give a sound and light alarm when the automobile is in danger, simultaneously reminds a driver of controlling automobile speed in a voice manner and keeping the distance from the automobile to the automobile ahead. In addition, when necessary, the system outputs brake signals to control the automobile to brake. Besides, the automobile anti-collision alarm system is large in measurement range, high in directivity, interference resistance, precision and practicality, fast in response time and simple in structure, and has high economic benefit and social benefit.

A general purpose network tone detection method and apparatus that allows the precise and accurate recognition of North American tones (MF, DTMF (Dual-Tone Multifrequency), and CPT (Call Progress Tones)) and international MF-R2 tones as well as taking into consideration other common tones such as Calling Card Service Prompt and Recall Dial. Through the use of the Discrete Fourier Transform (DFT) on small time windows and by providing phase continuity between these windows, the results of the successive DFTs may be combined and processed by a second DFT computation. This second DFT allows higher frequency resolution without requiring the re-computation of the DFT from the time samples. The resulting effect is a tone receiver with both high time and frequency resolution which consequently leads to robust and accurate tone recognition systems conforming even to the most stringent specification while maintaining low computational requirements.

The invention discloses a diffuse reflection spectrum analyzer of ultraviolet, visible and near-infrared on-line detection, comprising a housing. A lighting system, a probe, an optical beam splitting system, a signal acquisition system, a correction system and a spectrum processing system are arranged in the housing, wherein the lighting system, the signal acquisition system, the correction system and the spectrum processing system are jointly connected with a power supply system. The lighting system is used for irradiating ray of ultraviolet, visible and near-infrared wave band to light a detected object; the probe is used for collecting the ray of the detected object after diffuse reflection and sends the collected ray to the optical beam splitting system; a grating is utilized to form light of different wavelengths by ray; the signal acquisition system converts the optical signal into a digital signal, and the digital signal is collected; and the spectrum corrected by the correction system is processed, analyzed and displayed by the spectrum processing system so as to determine a detection result. The invention has the advantages of wide application range and accurate measurement.

The invention relates to an implementation method for processing an FBG (fiber bragg grating) sensing signal based on a three-point peek-seeking algorithm. The method comprises the steps of providing a peek-seeking processing flow, and giving three elements influencing the peek-seeking accuracy according to the flow, wherein reasonable selection of a window size is a key point for improving the peek-seeking accuracy, and the size of a spectral processing window is determined by adopting a derivation method; the spectrum in the window is resampled by arranging sampling intervals, and sparse spectrum data is acquired and subjected to polynomial fitting; a proper wavelength interval delta lambda is selected according to the fitting result, the coordinates of three points can be determined, the peak value of the FBG reflectance spectrum is detected, so that the central wavelength can be acquired, and external physical parameters can be demodulated.

The invention provides a near-infrared detector for meat, comprising a light source radiating the light on detected meat, a diffuse reflection probe for receiving a diffuse deflection light diffusedly deflected from the detected meat and a spectral processing system mounted on a monitor center, wherein the diffuse reflection probe is connected with the spectral processing system by an optical fiber. According to the near-infrared detector for meat and a detection method provided by the invention, the quality of the detected meat is detected using a near-infrared spectral analysis method so the detection method is a no-destructive detection method and has advantages of simple operation and high detection precision. In addition, the near-infrared spectrum is corrected by temperature, color and roughness information of the detected meat, therefore the detection precision is increased. In addition, the water content, fat content and protein content of the detected meat are completely analyzed, furthermore the quality of the detected meat is obtained, and therefore the reliability for detecting the quality of the detected meat is increased.

The invention provides spectroscopic systems and spectrometers employing an optical interference filter module having a plurality of bandpass regions. In certain embodiments, the systems include a mechanism for wavelength tuning/scanning and wavelength band decoding based on an angular motion of one or more filters. A spectral processing algorithm separates the multiplexed wavelength-scanned bandpass regions and quantifies the concentrations of the analyzed chemical and/or biological species. The spectroscopic system allows for compact, multi-compound analysis, employing a single-element detector for maximum performance-to-cost ratio. The spectroscopic system also allows for high-sensitivity measurement and robust interference compensation.

A programmable, many-band spectral imager based on addressable spatial light modulators (ASLMs), such as micro-mirror-, micro-shutter- or liquid-crystal arrays, is described. Capable of collecting at once, without scanning, a complete two-dimensional spatial image with ASLM spectral processing applied simultaneously to the entire image, the invention employs optical assemblies wherein light from all image points is forced to impinge at the same angle onto the dispersing element, eliminating interplay between spatial position and wavelength. This is achieved, as examples, using telecentric optics to image light at the required constant angle, or with micro-optical array structures, such as micro-lens- or capillary arrays, that aim the light on a pixel-by-pixel basis. Light of a given wavelength then emerges from the disperser at the same angle for all image points, is collected at a unique location for simultaneous manipulation by the ASLM, then recombined with other wavelengths to form a final spectrally-processed image.

An instrument having an illumination source configured to illuminate a field of illumination on a surface of a substrate that is configured to hold a sample. The field of illumination typically has a diameter greater than 1 micron or an area greater than that of at least one pad of an array. The instrument also includes an interferometer, and a detectors. The instrument is configured to perform Fourier transform imaging without single spot scanning or without line scanning. Additionally, the instrument may include an illumination light source, an array detector and spectral processing electronics. A method of collecting Fourier transform (FT) data is also disclosed.

The invention discloses a scattering spectrum detection method of true and false honey. After sequentially passing through a half-wave plate, a polarizing film, a quarter-wave plate and a first convex lens, laser of a first laser is incident in true honey in a glass tank, and a backward stimulated Brillouin scattering signal is generated; after being reflected through the polarizing film, the backward stimulated Brillouin scattering signal is reflected to a second convex lens through a reflector, and is collimated through a first slit after being converged through the second convex lens; the collimated signal passes through a non-spherical head mirror and a narrow second slit; spectral processing is carried out through a F-P etalon; the true honey in the glass tank is changed into false honey; the true honey and the false honey are analyzed, processed and compared through a first computer; respective backward stimulated Brillouin scattering spectrograms of the true and false honey are obtained, and the true and false honey can be identified. The scattering spectrum detection method disclosed by the invention has the advantages of being simple to operate, free of pollution, low in cost, high in speed, high in efficiency and the like in the event of detecting the true and false honey.

The invention discloses an ancient tomb inscription character recognition method based on a hyperspectral remote sensing technology, and the method comprises the steps: 1, sequentially obtaining the image data of an ancient tomb inscription through a hyperspectral instrument, and obtaining a plurality of hyperspectral images in each region; 2, preprocessing the hyperspectral image of the inscription; 3, selecting a spectral band to perform spectral processing on the hyperspectral image; 4, performing image enhancement on the inscription image after spectral processing; and 5, performing character recognition on the inscription image after image enhancement, performing similarity comparison with the inscription image to be recognized by utilizing a character image library, and outputting acharacter recognition result according to the similarity. According to the method, the characters of the inscription inscriptions in different environments can be recognized, good adaptability is achieved, the characters which cannot be recognized by naked eyes can be extracted, noise is smoothed while a picture containing the characters is enhanced, and the reliability, practicability and feasibility of the character recognition effect are good.

The invention relates to a multispectral laminated imaging method based on aperture scanning. An LED matrix is replaced by aperture scanning, single-beam light irradiation is adopted, light waves emitted from a sample pass through an aperture, low-resolution images from different positions of the sample are obtained through aperture cyclic scanning and hyperspectral processing, processing is carried out in a Fourier domain, and finally a high-resolution image of the sample is obtained. On the premise of realizing laminated imaging, the defects of an LED matrix are overcome. And the pupil function and the sample spectrum are iteratively updated, and the pupil function is converged, so that the resolution of the obtained imaging picture is higher. Hyperspectral imaging is introduced, and thenature of the sample is further understood through hyperspectral imaging, so that a clearer image is constructed, the sample can be analyzed more thoroughly, and conditions are provided for analyzingthe sample.

This disclosure pertains to a system and method configured for detecting fluid flow of a conduit. The method and system include using a flow sensor configured to sense fluid flow energy through the conduit, and a spectral processor in communication with the flow sensor. The spectral processor determines a spectral energy curve (SEC) of the fluid flow by obtaining, utilizing the flow sensor, raw flow data for the conduit and determining the SEC of the fluid flow energy. The method and system for determining fluid flow includes isolating, utilizing the SEC of the fluid flow energy, a flow-born energy of the conduit from an airborne environmental energy of the conduit, and a structural-born energy of the conduit, and detecting fluid flow based on the flow energy of the conduit.

The invention relates to a hyperspectral processing method and a waveband selection method. A hyperspectral classification model is trained by using a first training data set which is a full-band hyperspectral training data set, each training sample in the first training data set is input into the trained hyperspectral classification model, a second training data set for band selection is acquiredthrough a hyperspectral classification model, the second training data set is input into a waveband selection model for training, the waveband selection model outputs a selected waveband sequence number set, a corresponding waveband is extracted from the first training data set according to the selected waveband sequence number set to form a third training data set, and the hyperspectral classification model is trained by using the third training data set. According to the method, the purpose of hyperspectral band selection can be achieved, the band selected by the method is favorable for being matched with the hyperspectral classification model, and when the finally obtained hyperspectral classification model is applied, the precision can be effectively guaranteed.