123 results about "Atmospheric visibility" patented technology

The invention discloses a visibility measuring method based on an atmospheric fine particle spectrometer. The method comprises the following steps of: directly analyzing the atmospheric visibility from the angle of fine particle spectrum distribution in the atmosphere; and obtaining the atmosphere visibility according to the particle size distribution and the particle population concentration measured by the atmospheric fine particle spectrometer by analyzing the total extinction contribution of different sizes of particles to visible light. The method is simple, can realize atmospheric fine particle size distribution, particle population concentration distribution and the atmospheric visibility as well as contribution rate and distributed measurement of different sizes of particles to the atmospheric visibility by means of only the atmospheric fine particle spectrometer, has objective, accurate and reliable measurement results, ensures that the measurement process is not influenced by weather conditions (rain, fog, haze, sand and dust, and the like) and no target and background reference substances are required as references, and is easy to operate because instruments are installed and maintained indoors.

An atmospheric visibility measuring system is characterized in that the system can realize full-scale precise measurement of atmospheric visibility. The system adopts a measurement structure with a single light source and double baselines; a light source transmitting terminal and two signal receiving terminals are integrated into a whole body, which reduces the complexity of optical path debugging and measurement electronic system design, reduces requirements for field installation, improves system practicality, and reduces equipment cost. Meanwhile, the laser light source is subject to high frequency modulation, and an optical filter is installed in the front of a detector, which improve the system capability of resisting background light and stray light influence. In the signal sampling part, synchronous demodulation weak signal detection technology is adopted, which improves the measurement precision and measurement range of the system. The atmospheric visibility measuring system of the invention is applicable to industries of meteorological stations, airports, highway, harbours, atmosphere environment monitoring, and the like.

The radar is composed of laser, receiving optical unit and followed optical unit, signal detection and data acquisition unit as well as system operation control unit. Frequency doubling head is setup on laser, and optical axis of receiving telescope is parallel to direction of laser light. Received optical signal on diaphragm in back of telescope through optical fiber is coupled to opening of holophote. Optical signal from fiber through spherical mirror is reflected to holophote. Then, four optical paths formed from installed dichroic beam splitter, dichroic mirror and beam splitter are received by photomultipliers. The said photomultipliers are connected to amplifiers, which are connected to A/D card or photon-counting card in industrial control computer. The invention can detect horizontal atmospheric visibility in day or night or detect optical properties of aerosol at 1064nm and 532nm wavelengths in day or night for different area in troposphere.

The invention provides a transmission-type atmospheric visibility measuring device which has long-term reliability and can accurately measure visibility, and a measuring method. The transmission-type atmospheric visibility measuring device comprises a transmission part and a detection part, wherein the detection part comprises a receiving unit, a photoelectric signal processing unit, a data collecting unit and a computer control unit; the receiving unit adopts four-quadrant photodetectors; the light beam of each photodetector is provided with a photoelectric signal processing unit; signals output by the photoelectric processing unit is transmitted to the computer control unit through the data collecting unit; and the center coordinate of the four-quadrant photodetectors is controlled by a computer.

The invention relates to an atmospheric correction and regional mineral map spotting method utilizing multi-scene ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) remote sensing data, comprising the following nine steps of: (1) reading in ASTER data; (2) selecting reference data, wherein one-scene data is selected from multi-scene data as a reference for atmospheric correction; (3) carrying out the atmospheric correction on the reference data to obtain reference reflectivity data; (4) carrying out atmospheric correction on non-reference data to obtain non-reference reflectivity data; (5) calculating the overlay region spectral characteristic difference of the reference reflectivity data and the non-reference reflectivity data; (6) calculating the atmospheric water vapor content and the atmospheric visibility of the non-reference data; (7) newly carrying out the atmospheric correction on the non-reference data by utilizing the calculated atmospheric water vapor content and the atmospheric visibility to obtain non-reference reflectivity data; (8) carrying out inlaying treatment on the multi-scene reflectivity data including the reference data and the non-reference data; and (9) carrying out mineral identification and map spotting by utilizing spectral indexes. The method effectively eliminates inlaid gaps among the multi-scene data, thereby realizing the regional mineral map spotting.

The invention relates to based on laser backscattering type atmospheric visibility measuring method and apparatus. It includes the following steps: respectively transmitting and receiving laser backscattering signal for five times as middle gain and high gain, sampling 400 points in each the received signal; respectively computing each fault extinction coefficient while sampling, computing its average extinction coefficient for five sets after removing the point with big error; computing whole relative extinction coefficient by data fusion algorithm; deducing the atmospheric visibility by relative extinction coefficient inversion. The invention has the advantages of high measuring precision, little volume, light weight, wide application range, and no collaboration object.

The application provides a method, apparatus, and system for calculating atmospheric visibility and a radar. When an initial atmospheric extinction coefficient is calculated, the initial atmospheric extinction coefficient is corrected by using an angstrom wavelength exponent that is obtained in advance from a sun photometer or a particle spectrometer and is able to reflect a relationship of changing of the atmospheric extinction coefficient with a laser beam wavelength and an initial atmospheric extinction coefficient corresponding to a laser beam of a visibility laser radar with the wavelength deviating from the 550-nm laser beam farther is converter, so that an atmospheric corrected extinction coefficient of the atmospheric extinction coefficient corresponding to a laser beam with an approximate 550-nm wavelength is obtained; and thus when the atmospheric corrected extinction coefficient is introduced into an existing visibility calculation formula to calculate a visibility value ofa detected region, high matching between the visibility calculation formula and the atmospheric corrected extinction coefficient is ensured, so that the error rate of the visibility value is reduced and the accuracy of the visibility value is improved.

The invention provides an atmosphere visibility measurement device based on an optical cavity ring down spectroscopy technology and relates to a meteorological observation device. The atmosphere visibility measurement device comprises a saddle-shaped shell; a pair of high-reflectivity cavity mirrors are located at the two sides of a concave opening of the shell to form a ring down cavity; after laser transmitted by a laser transmitter penetrates through a polaroid, a 1/4 wave plate and a coupling lens in sequence and then is mitted into a first high-reflectivity cavity mirror, one path is reflected by the first high-reflectivity cavity mirror and is emitted into the polaroid through the 1/4 wave plate to be reflected and output; and the other path is vibrated in the ring down cavity, penetrates through the second high-reflectivity cavity mirror to be transmitted to a photomultiplier, and then is transmitted to a computer by a data acquisition card. By virtue of the atmosphere visibility measurement device, the technical problems that a measurement error is caused by the fact that the deviation is caused between the sampling of a sample to be detected for measuring the atmosphere visibility and the actual measurement in the prior art are solved. The atmosphere visibility measurement device has the beneficial effects that the open type ring down cavity can be in direct contact with atmosphere, and atmosphere extinction coefficient changes caused by gas molecules, aerosol and rainwater can be comprehensively measured, so that the accurate measurement of the atmosphere visibility is realized.

The invention proposes a method for predicting the atmospheric visibility. According to collected historical meteorological data, a new meteorological data set is established; a support vector machineis trained by using the new meteorological data set to obtain a support vector machine training model; a decision-making tree is trained by using the new meteorological data set to obtain a decision-making tree model; to-be-predicted data are normalized and the processed data are inputted to the trained support vector machine training model, the support vector machine training model carries out classification and then the processed data are inputted into the corresponding trained decision-making tree model to obtain final atmospheric visibility prediction data. According to the invention, with combination of the support vector machine and the decision-making tree, preliminary visibility classification is carried out and then the atmospheric visibility is predicted accurately. The operation is simple; the historical meteorological observation data only need to be processed slightly and the model is trained, so that the visibility is predicted.

The invention discloses an atmospheric visibility monitoring method and device. In the monitoring method, the video images took by a camera are received and used to determine the atmospheric light value of a green dark channel and recognize the red-blue card areas in the video images; in the recognized red-blue card areas, a pixel (p) is selected for monitoring, the brightness value and atmospheric light value of a pixel responding to the pixel (p) in the green dark channel are utilized to calculate the atmospheric transmission coefficient; the atmospheric transmission coefficient and corresponding distance information are used to calculate the atmospheric extinction coefficient, and finally the atmospheric visibility of the position where the camera took the pictures can be determined according to the atmospheric extinction coefficient. The provided method and device can effectively monitor the atmospheric visibility by using existed monitor cameras without installing any expensive visibility instrument.

The technical problem to be solved of the invention aims at providing a system for fast, conveniently and exactly calibrating an atmosphere visibility meter. The calibration system of the atmosphere visibility meter comprises a gradual change ratio light attenuation lens; the gradual change ratio light attenuation lens is positioned on an optical path between the transmitting end of the visibilitymeter and the receiving end of the visibility meter; and the gradual change ratio light attenuation lens, the transmitting end and the receiving end are positioned in cleaning atmospheric space. Theinvention completely considers the affects such as environment, temperature, weather variation, and the like, and can conveniently and fast calibrate the atmosphere visibility meter; by adopting the system, one atmosphere visibility meter can be calibrated only with 4-8 hours; the system has low system energy consumption and no environment pollution, and is convenient in operating and controlling;and the invention precludes the difficulties to the calibration of the atmosphere visibility meter, which are caused by human beings, weather, environment, temperature, humidity level, time, and thelike, and can scientifically, objectively and fast calibrate the various atmosphere visibility meters.

The invention provides a differential global position system (GPS) orientation azimuth introduction method which comprises the steps of (a) fixed station arrangement; (b) main movable station arrangement; (c) movable reference station arrangement; and (d) differential GPS orientation azimuth introduction. The differential GPS orientation azimuth introduction method solves the problem existing in long-distance alignment and has the advantages of being capable of adapting to long-distance orientation, solving the problem of difficult alignment caused by influence of atmospheric visibility of more than 10Km and atmospheric disturbance, reducing operation requirements of operators, reducing requirements for meteorological conditions and being capable of working except for thunderstorm weather. Due to only one theodolite, protective measures can be easily taken. In addition, due to aligning to the reference standard real object, the differential GPS orientation azimuth introduction method can work except for thunderstorm weather.

The invention relates to an online observation device and method for weather phenomena based on a light attenuation and scattering theory. The online observation device adopts an optical-mechanical structure with double light-source transmitting terminals and a single receiving end, and the optical-mechanical structure is as follows: a light source 1 transmits a precise parallel measuring light band; when falling precipitation particles pass through the measuring light band, the falling precipitation particles play a role of blocking and attenuating the light band; a photoelectric conversion signal is analyzed, so that the falling speed of the precipitation particles and the information of particle sizes can be obtained, the judgment to a precipitation weather phenomenon is realized, and the information such as precipitation intensity and raindrop spectrum can be provided; a light source 2 transmits a collimated measuring light beam; the scattering light intensity in an angle of horizontal 45 degrees of atmospheric particles in a sampling area on the light beam is detected, so that atmospheric visibility is reflected, and the identification of a visible weather phenomenon is realized. The device and the method realize the online automatic observation of a variety of weather phenomena, avoid adverse factors such as subjectivity in manual observation to cause observed results to be more accurate, timely, complete and integrated, have real significances on corresponding sciences such as meteorology, agriculture and environmental protection and engineering researches, and are widely applied to the fields of meteorological service observation, traffic safety scheduling, prevention and reduction of agricultural disasters, air quality monitoring and the like.

The invention belongs to the technical field of optical fiber sensing and visibility measurement, and particularly relates to an atmospheric visibility detection device based on the cavity ring-down technology and an application method. The device comprises a light source, a lead-in optical fiber, a resonant cavity, a lead-out optical fiber, a photoelectric detector and a data processing unit for calculating the optical loss data to obtain the visibility value of the detected sample arranged in sequence. The data processing unit obtains the loss of optical wave in the resonant cavity according to the characteristics of the resonant cavity and finally determines the visibility value of the detected sample through the optical loss. The device provided by the invention is compact in structure, the method is simple and easy to understand and convenient to implement, the detection accuracy of the detected sample visibility and the detection performance stability are greatly improved, and the device and method are applicable to the fields such as highway traffic, navigation, aviation and atmospheric pollutant monitoring.

The invention discloses an all-weather long-distance transmission type atmospheric visibility meter which comprises an optical transmitter and an optical receiver, wherein the transmitter comprises a first sealing cavity and a first housing; an LED light source and a modulation light driver are arranged in the first sealing cavity; the LED light source transmits square wave radiation with fixed frequency under the action of the modulation light driver; the receiver comprises a second sealing cavity and a second housing; a detector and a detector amplification circuit connected with the detector are arranged in the second sealing cavity; the detector is used for receiving the light radiation transmitted by the transmitter; the detector amplification circuit receives a synchronous signal, and processes a signal converted by the detector on the basis of the synchronous signal, so as to remove the background radiation. The all-weather long-distance transmission type atmospheric visibility meter utilizes the characteristic that the background radiation is mostly DC or low-frequency radiation to modulate the radiation signal with fixed frequency transmitted by the LED light source, and uses a method that the receiving end only receives the radiation signal with the fixed frequency to shield the background radiation.

The present invention provides a visibility observation method, and belongs to the meteorological detection field, and the method comprises the following steps: image acquisition, used to obtain a digital image containing ground objects; digital image processing, used for processing the digital image into a dark channel image; image transmittance distribution calculation, used to calculate and obtain a transmittance distribution map; transmittance distribution map processing, used to obtain a refined transmittance distribution map; and visibility calculation, used to calculate and obtain visibility by use of an image visibility observation model. According to the visibility observation method, separated erection of an artificial object is not needed, brightness, color, contrast ration and other optical information of the digital image are used fully for image analysis processing, atmospheric visibility information can be obtained, the cost is low, the structure is simple, and the application range is wide.

The invention provides a double-base-line transmissometer for the atmospheric visibility, which can be used for measuring the atmospheric visibility. The double-base-line transmissometer is simple in structure and mainly comprises a collimation transmitter device, a receiver device, an upper computer and combined power supplying equipment, wherein the receiver device comprises a first receiving machine and a second receiving machine. According to the double-base-line transmissometer, one collimation transmitter and the two receiving machines are adopted to form two measuring base lines so as to carry out extinction calculation; and compared with the single-base-line transmissometer for the visibility, the double-base-line transmissometer provided by the invention has the advantages that the system error caused by stains on the optical surface can be eliminated, the measuring accuracy of the transmissometer can be improved, and the stability of long-time measurement of the transmissometer is guaranteed, so that the double-base-line transmissometer is especially suitable for long-term work under the severe environments such as fields and open air.

The invention discloses a visible light equipment operating distance testing method based on a controllable objective target. The method comprises the following steps that: firstly, selecting the controllable objective target as a testing objective; then, according to the practical terrain condition of a testing place, determining a testing operating distance; according to the determined testing operating distance, the operating distance stipulated by an index and an objective size stipulated by the index, determining the radiation area of the testing objective target; according to a meteorological condition during practical testing, a meteorological condition stipulated by the index and the determined testing operating distance, determining the radiation temperature of the testing objective target; and finally, according to the radiation area and the radiation temperature of the testing objective target, testing an infrared system on the determined testing operating distance, if the infrared system can detect/ identify the objective, judging that the operating distance index of the infrared system under the stipulated condition is qualified, and otherwise, judging that the operating distance index of the infrared system is not qualified. By use of the evaluation method, the defect that the operating distance of the infrared system is restricted by atmospheric visibility and places when the operating distance of the infrared system is evaluated can be effectively eliminated, testing implementation difficulty is lowered, and testing efficiency is improved.

The invention provides a small high-performance scattering-type visibility measuring device and a measuring method thereof. The small high-performance scattering-type visibility measuring device is high in long-term reliability and accuracy. The small high-performance scattering-type visibility measuring device comprises a transmitting part and a detecting part, wherein the transmitting part comprises a stable light intensity driving source, a transmitting light intensity monitoring circuit, a transmitting light fiber and a fiber collimator; the detecting part comprises a receiving unit, an optoelectronic signal processing and acquiring unit and a computer control unit; the receiving unit receives and transmits scattered light signals by adopting fibers, the optoelectronic signal processing and acquiring unit is provided for detected scattered light beams, a signal output by the optoelectronic signal processing and acquiring unit is sent to the computer control unit, and the computer control unit is used for calculating the visibility.