58 results about "Atmospheric absorption" patented technology

A phase-sensing and scanning time-of-flight LADAR method and device are disclosed that take advantage of an atmospheric absorption bands within the solar IR spectrum.In the phase-sensing LADAR embodiment, an object is illuminated with electromagnetic energy such as a laser beam having a wavelength substantially equal to a predetermined atmospheric absorption band such as 1.39 microns. The transmitted laser beam is modulated at a predetermined frequency and has a first phase. The phase of the reflected and returned laser beam is altered proportional to the distance of the object and has a second phase. The first phase of the transmitted signal and the second phase of the received signal are compared and used to determine the distance of the object from the device. The system may comprise a modified laser that is tuned to operate in an atmospheric absorption band. A method to identify range ambiguity is disclosed by periodically altering the modulation frequency from a first modulation frequency to a second modulation frequency.In the scanning LADAR embodiment, an object is scanned or illuminated with electromagnetic energy having a wavelength substantially equal to a predetermined atmospheric absorption band at a first time and detects the reflection of the beam at a second time. The difference in time from the transmission of the scanning beam and the detection of the reflection of the beam from the object is used to calculate the range of the object.

The invention discloses a hyperspectral remote sensing classification method based on support vector machine under particle optimization. High-efficiency high-accuracy classification of hyperspectral data which are high in data dimension and large in data volume can not be met by existing methods, and no ideal selection method is provided for parameters of a support vector machine method. According to the method, hyperspectral data is preprocessed, abnormal wave bands are removed under the influence of factors such as atmospheric absorption, then a certain proportion of data of various types are selected at random to serve as training data, a Gauss radical basis function is selected to serve as a kernel function mode, a classifier based on the support vector machine is trained, a speed updating formula of changing weight is designed, a certain proportion of particle mutation is guaranteed, an optimal classifier parameter is selected and obtained according to a particle swarm optimization algorithm, a plurality of second classifiers are trained, and a type which wins most votes is selected to be a final predicted type of data points according to a voting mode. According to the method, parameter optimization convergence ability of the classifier is strengthened, and the classification performance of hyperspectral remote sensing images is improved.

An automotive occupant position restraint apparatus senses a position of an occupant of a motor vehicle. An optical energy source emits optical energy that is substantially limited to a first range of wavelengths that corresponds to an atmospheric absorption peak. An optical energy receiver receives the optical energy emitted by the optical energy source after the optical energy has been reflected within a passenger compartment of the motor vehicle. A range of wavelengths that the receiver is operable to receive is substantially limited to a second range of wavelengths that corresponds to the atmospheric absorption peak.

The invention discloses an atmospheric absorption spectral measurement system based on a time-resolved optical frequency comb, and a method. According to the atmospheric absorption spectral measurement system, firstly, the time-resolved variable optical frequency comb is generated, then subjected to laser power amplification and nonlinear transformation, and finally applied to gas absorption spectral measurement. Specifically, the time-resolved optical frequency comb is generated through a frequency shift loop and an optical fiber delay line firstly to serve as probe light, the output opticalfrequency comb is linear polarization pulse light, and thus power amplification and frequency nonlinear transformation are facilitated. According to the atmospheric absorption spectral measurement system based on the time-resolved optical frequency comb, and the method, the optical frequency comb can directly probe a precise gas spectrum on the time domain, system parameters can be conveniently adjusted, thus the system is applied to different atmospheric spectral measurement, and then the parameters of concentration, temperature, pressure intensity and the like on a corresponding gas integralpath can further be obtained through inversion.

A phase-sensing and scanning time-of-flight LADAR method and device are disclosed that take advantage of an atmospheric absorption bands within the solar IR spectrum.In the phase-sensing LADAR embodiment, an object is illuminated with electromagnetic energy such as a laser beam having a wavelength substantially equal to a predetermined atmospheric absorption band such as 1.39 microns. The transmitted laser beam is modulated at a predetermined frequency and has a first phase. The phase of the reflected and returned laser beam is altered proportional to the distance of the object and has a second phase. The first phase of the transmitted signal and the second phase of the received signal are compared and used to determine the distance of the object from the device. The system may comprise a modified laser that is tuned to operate in an atmospheric absorption band. A method to identify range ambiguity is disclosed by periodically altering the modulation frequency from a first modulation frequency to a second modulation frequency.In the scanning LADAR embodiment, an object is scanned or illuminated with electromagnetic energy having a wavelength substantially equal to a predetermined atmospheric absorption band at a first time and detects the reflection of the beam at a second time. The difference in time from the transmission of the scanning beam and the detection of the reflection of the beam from the object is used to calculate the range of the object.

The invention provides a Ka-band satellite channel modeling method integrated with meteorological factors and aims at solving the problems that data classification is lack of theoretical basis and simulation data are difficult to obtain in a traditional Ka-band satellite channel modeling process. The method comprises the following steps of: firstly, analyzing the propagation characteristic of a Ka-band satellite channel and the influences of multipath propagation, rainfall, atmospheric absorption, atmospheric scintillation and other factors to satellite channel modeling; and secondly, establishing a multistate Markov model of the Ka-band satellite channel by using a principal component analysis and fuzzy clustering analysis method. Through comparing the electrical level crossing-over rate and the average decay time of the established model with the electrical level crossing-over rate and the average decay time of a former model, the accuracy and the effectiveness of the channel model are checked, the theoretical basis is provided for resisting the rain attenuation of the Ka-band satellite channel, and meanwhile, Ka-band satellite channel modeling method has great practical significance in technical research on the aspects of signal modulation, coding mode and power control of Ka-band satellite communication.

The invention relates to a terahertz waveguide cavity filter composed of an upper cavity located at the upper portion and a lower cavity located at the lower portion in stacking mode. The upper cavity is sealed on the lower cavity, and a waveguide cavity with a hollow-out structure is arranged at the combining position of the upper cavity and the lower cavity and is located in the lower cavity. A third resonant cavity is connected with a waveguide output section in series through a fifth sensitive coupling window. A waveguide input section, a first sensitive coupling window, a first resonant cavity, a third sensitive coupling window, a second resonant cavity, a second sensitive coupling window and the waveguide output section are sequentially connected in series to form a coupling path to serve as a main signal channel. The waveguide input section, a fourth sensitive coupling window, a third resonant cavity, a fifth sensitive coupling window and the waveguide output section are sequentially connected in series to form a second coupling path for forming a transmission zero point at the passband low end. The terahertz waveguide cavity filter has the advantages that a passband of the waveguide cavity filter is in a frequency range of 380-390GHz, communication and the like under specified conditions can be achieved by utilizing an atmospheric absorption window in the frequency range.

The invention discloses an inversion method for the laser transmittance of the whole atmosphere. The method comprises the following steps of: measuring an aerosol optical depth of the whole atmosphere by selecting a specific wavelength, and performing inversion to obtain the aerosol optical depth of the whole atmosphere of other wavelengths; and inverting the transmittance of the whole atmosphere. The method has the advantages that: inversion of the transmittance of the whole atmosphere in ultraviolet, visible and infrared bands is realized by using a multi-band solar radiometer and atmospheric model or local atmospheric measured data and high-resolution atmospheric absorption optical depth computation software; and the problem about measurement of the laser transmittance of the whole atmosphere in a broad spectrum is solved.

The invention relates to a method and device for simultaneously recycling methylbenzene and dimethyl formamide in industrial waste gas by using a solvent. Water and a solvent N-formylmorpholine in a mass ration of 1:(3-5) are used as absorbents to simultaneously absorb methylbenzene and DMF (N,N-dimethylformamide) in waste gas in an atmospheric absorption tower, and primary vacuumized rectification and secondary vacuumized rectification are sequentially adopted to recycle the DMF and methylbenzene in the waste gas. The content of DMF in the waste gas after removing the methylbenzene and DMF is approximate to zero, and the content of methylbenzene can also be reduced to several ppm, thereby achieving the emission standard. The solvent in the method provided by the invention can be recycled, the DMF recovery rate is up to more than 99%, and the purity is up to 99.9%. The technique not only enhances the recovery value, but also reduces the emission of organic waste gas, thereby solving the problem that industrial waste gas can not be easily treated thoroughly in synthetic leather, textile, printing and dyeing and other industries. Therefore, the invention has high implementation value, social benefit, environmental benefit and economic benefit.

A lidar system with improved signal-to-noise ratio in the presence of solar background noise. The lidar system can comprise a light source to emit light toward a target. The light source can have an operating wavelength which lies within a band that delineates a relative maximum in atmospheric absorption. The lidar system can also include a detector to detect scattered light from the target and a processor to determine a characteristic of the target based on a characteristic of the scattered light received at the detector.

The invention discloses a spectrum drifting detection method for an interference type hyperspectral imager. The method comprises the following steps: (1) converting the spectroscopic data of a hyperspectral imager into radiance on entrance pupil position of each wave band to serve as spectrum radiance to be detected; (2) obtaining the radiance on entrance pupil position of satellite height; (3) obtaining radiance on entrance pupil position of each wave band by the response function of the hyperspectral imager to serve as reference spectrum radiance; (4) comparing the positions of the spectrumradiance to be detected and the reference spectrum radiance on an atmospheric absorption peak, determining whether the offset of the spectrum radiance to be detected and the reference spectrum radiance by a judgment function; turning to the step (5) if yes; otherwise, regulating the regulation amount of wave band and bandwidth in the response function of the hyperspectral imager, and circularly judging from step (3); and (5) carrying out inverse fast Fourier transform to the interference data of the hyperspectral imager for the hyperspectral imager spectrum drifting amount determined when a constraint condition is satisfied to obtain a spectrum data graph of the hyperspectral imager, which removes spectrum drifting.

The invention discloses an aircraft engine noise simulation synthesis audible method, system and device, and belongs to the technical field of aircrafts, and the method comprises the steps: 1, readingan input file; 2, preprocessing the input file; 3, calculating the total sound pressure level of each 1 / 3 frequency band of the broadband noise; 4, carrying out short-time fast Fourier transform on the empirical data, analyzing and deriving low-frequency oscillation, and modulating the amplitude of the 1 / 3 frequency band sound pressure level by using the low-frequency oscillation; 5, synthesizingbroadband noise of the aircraft through a subtraction synthesis method; 6, calculating the frequency and the amplitude of each single tone and harmonic waves thereof; 7, independently modulating theamplitude and frequency of each single tone by using low-frequency oscillation; 8, performing single-tone noise synthesis; 9, superposing the broadband signal and the single-tone noise signal of the aircraft; and 10, adding direction-related gain and absolute time delay as well as time delay and gain corresponding to diffusion loss and atmospheric absorption to the aircraft noise signal generatedin the synthesis stage.

The present invention discloses a mobile terminal location method, device and system based on wave beam training. The location method comprises the steps of: emitting location requests for at least two stations by a mobile terminal; receiving wave beam training messages sent by the stations, marking the maximum receiving signal intensity received by each station, feeding back codeword informationcorresponding to the maximum receiving signal intensity to each station; receiving the location information sent by the stations through different measurement wave beams, and marking the receiving signal intensity of the measurement wave beams of each station; calculating the propagation principal diameter azimuths of the stations according to the receiving signal intensity ratios of different wave beams and an antenna swing angle; and estimating the position coordinates of the mobile terminal through adoption of the position coordinates and the propagation principal diameter azimuths of eachstation according to a space geometry relation. The mobile terminal location method, device and system employ the wave beam training process to obtain the information required by the measurement of the propagation principal diameter azimuth of each station, are little in cost and high in location precision, and can eliminate the influences of millimeter wave atmospheric absorption and rainfall declination.

The invention discloses a thermal infrared high spectral remote sensing data on-track spectral calibration method, comprising steps of (1) inputting an atmosphere parameter and an imaging parameter to MODTRAN atmosphere radiation transmission simulation software to obtain a simulated 1nm ultrahigh resolution entrance pupil brightness spectrum, wherein the atmosphere parameter and the imaging parameter are obtained during a process of obtaining thermal infrared high spectral remote sensing data; (2) taking center wavelengths lambda i and FWHM delta lambda i which are obtained by laboratory spectrum calibration as initial values, and constantly regulating center wavelengths (lambda i+delta lambda i) and FWHM (delta lambda i+delta delta lambda i) to perform convolution operation on the ultrahigh resolution entrance pupil radiation brightness spectrum to obtain a simulated sensor entrance pupil brightness spectrum; and (3) choosing a simulated atmosphere absorption band and a near entrance pupil radiation brightness spectrum and a radiation brightness spectrum obtained by a sensor, performing NODD conversion on the near entrance pupil radiation brightness spectrum and the radiation brightness spectrum, comparing normalized optical thickness differential spectrums obtained through NODD conversion, obtaining optimal variables delta lambda i and delta delta lambda i of the center wavelength and the FWHM through an optimal algorithm and finally obtaining the optimal center wavelength and the FWHM. The thermal infrared high spectral remote sensing data on-track spectrum calibration method is accurate, fast and easy to operate.

An additive manufacturing apparatus including a chamber, a build platform movable in the chamber such that layers of flowable material can be successively formed across the build platform, a unit for generating an energy beam for solidifying the flowable material, a scanning unit for directing the energy beam onto selected areas of each layer to solidify the material in the selected areas and a getter for absorbing oxygen, nitrogen and / or hydrogen from atmosphere in the chamber.

The invention provides a static meteorological satellite channel modeling method, which comprises the following steps of: according to the spatial distribution situation of a satellite-to-ground link, successively analyzing the influence of free-space loss, ionospheric scintillation, atmospheric absorption, multipath and shadow on a channel link; according to the weather situation, establishing a static meteorological satellite Rice channel model and a Suzuki channel model; and according to a Markov chain, linking the Rice channel model and the Suzuki channel model in one dynamic model to reflect the influence on the transmission characteristic of the static meteorological satellite channel by the weather state change. The method disclosed by the invention has an important value on the signal modulation, the coding mode and the power control technology of static meteorological satellite communication.

A spectrum measurement device that recognizes objects to be measured on the basis of spectral data of observed light that is detected by a spectrum sensor capable of measuring wavelength information and light intensity information. The spectrum measurement device comprises a lighting device capable of projecting light that includes a wavelength region with a high atmospheric absorption index and recognizes the distance from a vehicle to an object to be measured through a computation that uses spectral data of observed light that is obtained from the object to be measured whereupon light of at least the wavelength region with the high atmospheric absorption index is projected.

Combined removal of both ammonia from an ammonia-containing waste gas and nitrogen oxides from a nitrogen oxide-containing waste gas in a combined ammonia / urea synthesis plant is accomplished by mixing the gases and employing one or both of selective non-catalytic reduction at a temperature of 850° C. to 1100° C. or selective catalytic reduction at a temperature of 150° C. to 550° C., in which the ammonia and the nitrogen oxides react with one another to give nitrogen and water, the ammonia-containing waste gas derived from a low-pressure and / or atmospheric absorber of the urea synthesis plant, and the nitrogen oxide-containing waste gas derived from a flue gas duct of a primary reformer of the ammonia synthesis plant, both the ammonia and the nitrogen oxides of the mixed waste gas flows being depleted simultaneously during the same process step.

A radiation temperature measuring device includes: an infrared sensor that detects a wavelength including an absorption band by atmosphere; an absorption rate calculation unit that calculates an absorption rate by the atmosphere when measuring a surface temperature of an object from output of the infrared sensor; an output storage unit that stores conversion information for converting the output of the infrared sensor into the surface temperature of the object; a surface temperature calculation correction unit that calculates the surface temperature of the object from the output of the infrared sensor, the absorption rate calculated by the absorption rate calculation unit, and the conversion information; and an absorption rate storage unit that stores in advance the absorption rate by the atmosphere when the conversion information is set, in which the calculated surface temperature of the object is corrected with the absorption rate stored in the absorption rate storage unit.

The invention discloses a device and method for measuring an atmospheric absorption coefficient based on phase perturbation. The device comprises a mechanical compensation zoom system, a sample storage pipe, an optical fiber interferometer and an extinction tube, wherein the sample storage pipe also comprises a sample inlet and a sample outlet. In the invention, a relation between the phase perturbation and the atmospheric absorption coefficient is established, the effects of dispersion and absorption to the atmosphere are effectively separated, the atmospheric absorption coefficients corresponding to parallel laser beams with different wavelengths can be measured in a non-contact way while the original properties of the atmosphere are maintained, the evolution law of the atmospheric absorption coefficient along with time can be detected, and the method has the characteristics of high detection speed, high sensitivity and simple operation.

The invention discloses an in-orbit absolute radiation calibration method for simplifying radiation transfer calculation based on multi-energy-level targets. According to the invention, a gray-scale target (target plate), a reflector, an active light source and other multi-energy-level targets are used as references, and separation of target radiation from atmospheric path radiation and surface-atmosphere coupled radiation is calculated by using linear regression; and the in-orbit absolute radiation calibration of optical remote sensors is realized through a combination of measurement of the optical thickness of on-site atmosphere, a ratio of diffusion to total irradiance (needed if the target is a diffusion target) and the energy of the multi-energy-level targets, and calculation of the transmittance of atmospheric absorption gases. The in-orbit absolute radiation calibration method of the invention uses data actually measured on the ground as main data and does not depend on radiation transfer calculation, so the influence of aerosol, atmosphere modes and other factors is reduced; and the in-orbit absolute radiation calibration method can realize full-dynamic-scope high-precisioncalibration of the optical remote sensors.

The invention discloses a gasification and expansion power device of liquid gas. An internal combustion engine is constructed to be a substrate, and the liquid gas is automatically gasified and expanded to push a piston to do work so as to produce kinetic energy in a normal-temperature and normal-pressure cylinder. The device is in an environmentally-friendly and pollution-free energy supply mode, and can replace the conventional power devices which supply energy by burning fossil fuels, such as internal combustion engines, steam engines and the like; and in the energy supply mode, most of fossil fuels can be replaced and the consumption of the fossil fuels can be greatly reduced. The power device mainly has the advantages that: a gasification reaction in a physical reaction is used as the energy supply mode, and a new substance is not produced, so environmental friendliness and pollution freeness are guaranteed; the initial energy of the power device is originated from solar energy; the sun irradiates the earth, and most of heat is absorbed by the atmosphere; and most of energy of the reaction is gasified and expanded to produce kinetic energy when heat in the air is absorbed by the liquid gas at normal temperature higher than a gasification point.

The invention discloses an on-orbit absolute radiation calibration method for an optical sensor based on a reflector array, which takes the reflector array as a reference target to separate target reflection radiation from atmospheric path radiation, earth-atmosphere coupling radiation and ground object thermal radiation by using linear regressive calculation. On-orbit absolute radiation calibration for a middle-infrared band optical remote sensor through measuring the field atmospheric optical thickness, temperature, humidity and pressure profile and reflector specular reflectance and combining calculation for the atmospheric absorption gas transmission rate. The on-orbit absolute radiation calibration technology for the middle-infrared band optical remote sensor mainly relies on ground measured data, and does not depend on radiation transmission calculation, thereby reducing influences of factors such as an aerosol and an atmospheric mode. The calibration technology can realize full-dynamic-range and high precision calibration for the middle-infrared band optical remote sensor.

The invention discloses an engine jet flame characteristic test device and method in the atmospheric absorption wave band. The device comprises a Fourier spectrometer, a high-temperature calibration black body and a thermal infrared imager, wherein the Fourier spectrometer, the thermal infrared imager and an engine to be tested are all located in the plane of an engine test bed, the Fourier spectrometer and the body of the engine to be tested are located on the same side of a nozzle of the engine to be tested, and the thermal infrared imager is located on the other side of the nozzle of the engine to be tested. The test method comprises the steps that first, the atmospheric transmissivity of a tested environment is calculated, and a lens of the Fourier spectrometer is selected, and the position of the thermal infrared imager is chosen; second, the high-temperature calibration black body is used for carrying out multi-point radiometric calibration; third, the test device is started, the Fourier spectrometer carries out data acquisition, and the thermal infrared imager acquires infrared image data; finally, atmospheric correction processing is carried out on the acquired data. According to the engine jet flame characteristic test device and method in the atmospheric absorption wave band, the path length of radiation transfer is fully reduced, absorption of atmosphere to jet flame radiation is reduced, high-precision atmospheric correction is achieved through dynamic data, and the precision of test data is improved.

The invention discloses an online calibration method of a tunable filter for solar observation. The online calibration method of a tunable filter for solar observation is composed of a telescope system (1), a filter to be calibrated (2), a camera (3), a reference light intensity recording system (4), a beam splitter (5), and a reflector (6). The tunable filter is widely applied to solar narrowbandspectral imaging observation, and requires regular on-line calibration. A traditional method performs imaging observation on a quiet area of the solar disk, and the change of solar light intensity during the calibration process may have a greater impact on accuracy of calibration of the filter. The online calibration method of a tunable filter for solar observation corrects the solar light intensity change caused by the non-solar atmospheric absorption phenomenon in the calibration process through real-time solar light intensity detection, and can effectively overcome the solar light intensity change during the long-term calibration process and weaken the influence of thin cloud on solar light intensity during the calibration process. The online calibration method of a tunable filter forsolar observation can be applied to online calibration of various tunable filters in solar observation, can significantly reduce the requirement for on-line calibration of solar light intensity stability, and can improve the calibration accuracy.

The invention discloses an intelligent attitude and orbit control system based on air-breathing electric propulsion, and belongs to the field of spacecraft attitude and orbit control. The system is composed of an atmosphere absorption module, an intelligent adjustment module, an attitude and orbit control module, an energy supply module, an attitude execution module and a resistance compensation module. Atmospheric molecules in an orbit space are absorbed as a working medium, and then working medium supply is adjusted through the intelligent adjustment module according to the actual working medium flow rate requirement so as to support a pulse plasma thruster in the attitude execution module to carry out attitude adjustment and support a Hall thruster in the resistance compensation moduleto carry out resistance compensation and orbit transfer work. Solar panels are attached to the periphery of the system, and charging is conducted by absorbing solar energy so as to provide electric energy for all parts needing electric energy in the system. The system has the advantages that under the condition that a satellite carries a small number of working medium or even does not carry the working medium, absorbed atmosphere serves as the working medium to support various thrusters to carry out attitude adjustment and orbit transfer tasks, and working medium waste is avoided through intelligent adjustment.

A spectrum measurement device that recognizes objects to be measured on the basis of spectral data of observed light that is detected by a spectrum sensor capable of measuring wavelength information and light intensity information. The spectrum measurement device comprises a lighting device capable of projecting light that includes a wavelength region with a high atmospheric absorption index and recognizes the distance from a vehicle to an object to be measured through a computation that uses spectral data of observed light that is obtained from the object to be measured whereupon light of at least the wavelength region with the high atmospheric absorption index is projected.

The present invention relates to an atmospheric absorption band infrared radiant luminance calibration method, apparatus and system. The method comprises: aligning a thermal imager light path axis with a central position of a black body, adjusting a relative position between a thermal imager and a black body and a black body temperature, collecting infrared images of different black body temperatures at different relative positions; reading infrared image gray values of a same black body temperature obtained at the different relative positions, establishing a first relational expression between a relative position and an infrared image gray value, and determining an infrared image gray value at a thermal imager detector actinal surface at different black body temperatures; establishing a second relational expression between a black body temperature and an infrared image gray value at the thermal imager detector actinal surface, and converting the second relational expression into a correspondence between an infrared image gray value and an infrared radiant luminance, so as to obtain an infrared thermal imager calibration curve. According to the atmospheric absorption band infraredradiant luminance calibration method, apparatus and system, the calibration curve is constructed, so that quantitative analysis processing on wave band infrared radiation characteristic data of a target in a typical atmospheric absorption band is implemented.

The invention discloses an infrared stealth superstructure compatible with thermally induced variable emissivity and frequency selective heat dissipation. The infrared stealth superstructure comprises a plurality of electromagnetic resonance units which are arranged on a substrate in a periodic arrangement mode, and each electromagnetic resonance unit comprises an emissivity regulation and control layer and a dielectric layer which are sequentially stacked from bottom to top, and a pluraltiy of metal columns which are periodically arranged on the dielectric layer; the emissivity regulation and control layer is prepared by embedding a phase change material into a metal layer stacked on the substrate. According to the invention, the emissivity can be modulated in atmospheric transmission windows of 3-5 microns and 8-14 microns, meanwhile, the thermal radiation of 5-8 microns of an atmospheric absorption wave band is enhanced to actively dissipate heat, and the infrared stealth superstructure has a relatively wide emissivity regulation and control range and can adapt to various infrared stealth scenes.