316 results about "Solar altitude" patented technology

This invention generally relates to automated shade systems that employ one or more algorithms to provide appropriate solar protection from direct solar penetration; reduce solar heat gain; reduce radiant surface temperatures; control penetration of the solar ray, optimize the interior natural daylighting of a structure and optimize the efficiency of interior lighting systems. The invention additionally comprises a motorized window covering, radiometers, and a central control system that uses algorithms to optimize the interior lighting of a structure. These algorithms include information such as: geodesic coordinates of a building; solar position; solar angle solar radiation; solar penetration angles; solar intensity; the measured brightness and veiling glare across a surface; time, solar altitude, solar azimuth, detected sky conditions, ASHRAE sky models, sunrise and sunset times, surface orientations of windows, incidence angles of the sun striking windows, window covering positions, minimum BTU load and solar heat gain.

The invention discloses an automatic tracking linkage mechanism of a solar energy concentration photovoltaic power generating array, which comprises a solar concentrator array, an altitude linkage mechanism, and an azimuth linkage mechanism. The solar energy concentration photovoltaic power generating array drives the whole array of all concentrators to obliquely track a solar altitude through a set of altitude driving mechanism, and drives the whole array of all concentrators rotate around a transmission shaft to track a solar azimuth through a set of azimuth driving mechanism. The whole solar energy concentration photovoltaic power generating array only adopts the set of the altitude driving mechanism and the set of the azimuth driving mechanism, so that the whole array of all concentrators realize tracking the running of the sun by two-dimensional linkage, and the tracking cost is low; moreover, the altitude driving mechanism and the azimuth driving mechanism are formed by simple mechanisms completely, so that the whole solar energy concentration photovoltaic power generating array is manufactured easily, and has high tracking accuracy and strong capability of strong wind resistance.

The invention relates to a method for improving the orbit-transferring safety of an inclined orbit satellite, wherein the problem of energy-source shortage of the inclined orbit satellite in the period of orbit-transferring motorization under the condition of high solar angles is solved through the reasonable adjustment of flight events by considering the condition of solar altitude angles in the designing process of a flight program, and meanwhile, flight-control operation can be simplified. The discharging time of a storage battery in the period of orbit-transferring ignition can be shortened by designing the flight program according to the method, so that the load power in the power-supplying period of the storage battery is reduced, therefore the discharging depth of the storage battery is reduced, the energy-source safety of the satellite is ensured, and a launch window is not limited by solar illumination angles.

The present invention relates to a method of calculating a Topography Adjusted Vegetation Index (TAVI) based on a band ratio model and a solar altitude angle. The method includes the folio wing steps: obtaining the apparent reflectance data of a remote sensing image through image preprocessing, analyzing the quality of the image and numerical distribution, calculating a Shadow Vegetation Index (SVI), and constructing a TAVI combinational algorithm:TAVI=BirBr+f(Δ)·1Br,calculating an adjustment factor f (Δ) with the solar altitude angle, and finally obtaining anti-topographic effect TAVI vegetation information. The TAVI in the present invention is composed of two band ratio submodels RVI and SVI, the denominators of both of which are red band data of a remote sensing image, and the adjustment factor f(Δ), which is calculated by a solar altitude angle as a parameter with a sensor factor applied, has great physical significance. The TAVI calculation method does not need digital elevation model (DEM) data and remote sensing image classification when not depending on ground survey data,, and ensures that the interference of the topographic effects with the vegetation information can be effectively eliminated by the TAVI, thereby avoiding the problem of reduced inversion accuracy of ground vegetation information due to different registration accuracy of a remote sensing image and DEM data.

The invention provides an MODIS remote sensing monitoring method for the vertical distribution pattern of eutrophic lake water algae. The method includes: acquiring the vertical distribution pattern of the algae by means of field monitoring; on the basis of field measured water surface spectral information and environmental information, creating a ground measured spectral data (Rrs) based remote sensing monitoring method for vertical algae distribution; acquiring the quantitative relationship between ground monitoring and remote sensing reflectance Rrs and simulated Rrc after Rayleigh scattering correction by simulating different aerosol types and thicknesses and different solar altitudes, satellite observation angles and azimuthal angles; further promoting the ground measured spectral data based monitoring method for vertical algae distribution to MODIS satellite image data subjected to Rayleigh scattering correction. On the basis of the method, interannual and inter-monthly change rules and spatial distribution of the vertical distribution pattern of the eutrophic lake water algae can be acquired accurately, and scientific support is provided for scientific decision-making on water resource management and water environment protection water conservancy and environmental protection departments.

An estimated value or a predicted value of an output of photovoltaic generation is easily and properly determined. A learning processor constructs an output calculating model based on a measured value of an output of photovoltaic generation, sunshine hours, and a solar altitude in a learning period. The output calculating model calculates the output of the photovoltaic generation based on the sunshine hours and the solar altitude. An output calculator calculates an estimated value of the output of the photovoltaic generation in an estimation period and a predicted value of the output of the photovoltaic generation in a prediction period based on a measured value of the sunshine hours in the estimation period and the solar altitude or a predicted value of the sunshine hours in the prediction period and the solar altitude. Additionally, the features may be applied to a photovoltaic power system.

The invention provides a high-precision satellite MODIS (Moderate-resolution Imaging Spectroradiometer) monitoring method for chlorophyll a of a eutrophic lake water body. The method comprises the following steps: screening a chlorophyll a evaluation index (NDBI) which is sensitive to the concentration change of the chlorophyll a and is not influenced by high suspended solids; obtaining a quantitative relation between the NDBI and the concentration of the chlorophyll a on the basis of biological optical model simulation; combining spectral information of the water body and the corresponding concentration of the chlorophyll a of the water body monitored in the field in Chaohu Lake in year 2013-2014, so as to obtain a chlorophyll a inversion algorithm based on a ground measured spectrum (Rrs) and the NDBI; simulating different aerosol types and thicknesses, different solar altitudes, satellite observation angles and azimuth angles, so as to obtain a quantitative relation between the ground monitored remote sensing reflectance (Rrs) and simulated Rrc subjected to Rayleigh scattering correction; and further extending the chlorophyll a inversion algorithm based on ground measured spectral data to satellite image data subjected to the Rayleigh scattering correction. According to the method, the inter-annual and inter-monthly change rules and space distribution of the rules of the concentration of the chlorophyll a of a eutrophic lake can be accurately obtained.

The invention discloses a method for on-orbit optimization of imaging parameters of a TDI CCD camera. The method is suitable for different imaging conditions. The method comprises the following steps of 1, aiming at a season change, building a global ground feature reflectivity database by an acquired satellite image, 2, making solar spectral radiance and integrating sphere spectral radiance equivalent by normalized responsibility of a camera system, and acquiring a relationship between a camera system output and apparent radiance according to a radiometric calibration test result, and 3, by the global ground feature reflectivity database and a solar altitude change, acquiring a camera parameter arrangement suggestion by the above computed result. Aiming at different ground feature objects and imaging conditions, the method can realize real time calculation of TDI integration class and gain and provide the calculation result for a user. The method guarantees accuracy, real-time performances and reliability of on-orbit parameter arrangement and improves on-orbit imaging performances and image quality of an optical remote sensor.

The invention relates to an automatic removing method of a vehicle-mounted laser point cloud noisy point based on angle and intensity. The operation steps comprise: acquiring point cloud data by utilizing a laser scanner, and calculating the solar altitude angle according to the time and longitude and latitude of each scan circle of the point cloud data; solving the equation of a POS (point of sale) plane of each scan circle time according to the posture and position information of a POS system; calculating an included angle between a connection line formed by three-dimensional coordinate points in a scan circle and the POS center and the POS plane, calculating the difference value of the included angle and the complementary angle of the solar altitude angle, comparing the difference value and the threshold value of the angle, and determining the points less than the angle threshold value to be the noisy points; calculating the covariance matrix of point coordinates in neighborhood of the noisy points, solving the property value of the matrix, determining the coplanarity and colinearity of the matrix, and determining the points less than the threshold value to be noisy points again; and calculating the variance value of intensity distribution in the neighborhood of the noisy points, and determining the points greater than the threshold value as the noisy points. The method has the advantages of high automation degree, quickness and high efficiency.

A multi-plane reflecting mirror solar energy condensation device includes a foundation component, a rotation component, a planemirror supporting structure and a multi-plane reflector array, wherein the multi-plane reflector array consists of a plurality of independent single planar reflecting mirrors; the plane supporting structure includes an H-type main frame and a plurality of parallel support strips fixed on the H-type main frame; the independent single planar reflecting mirrors are connected with the parallel support strips through universal joint brackets; the rotation component includes an electric rotating disc and an electric push rod; the electric push rod expands and contracts to push the pitching angle of the H-type main frame, so as to enable the multi-plane reflecting mirror array to track the solar altitude; and the electric rotating disc rotates to enable the multi-plane reflecting mirror array to track the solar azimuth. The device provided by the invention can be used for acquiring the most uniform focusing spots, fundamentally solves the problem of efficiency reduction caused by nonuniform condensation in photovoltaic power generation, has a simple structure, and is low in cost.

A data acquisition device of a tree canopy analyzer comprises an optical filter, a sensing device which is connected with the optical filter in a sealing way; the sensing device is connected with an acquisition control unit and a memory device; the sensing device is an array which comprises a plurality of opto-electrical sensing units arranged in the same plane. The device measures characteristic parameterS of the tree canopy structure on the plane; when in working, the device is arranged under the canopy of trees or forest; the intensity of the sun illumination permeating the canopy and the change process of the facula structure in a period of time are measured so as to calculate leaf area indexes, extent of porosity, extinction coefficient of the canopy and anisotropic characters of the structure parameters; as the leaf space distribution, the zenith angle of the sensor and the solar altitude can be considered at the same time, the error can be reduced; in addition, as a photoelectric sensor is adopted, the optical imaging error is reduced; and the sensing unit is connected with a memory device, thus realizing data measurement in long period.

The invention discloses a method and system of measuring solar energy on the spot. The method uses the camera with fish-eye lens to soot the picture of the hole hemisphere, making sure every point's altitude angle and azimuth angle in the picture by the law of imagery and find the corresponding local solar trace picture according to the geographic latitude of the measuring point, connecting the solar trace with the orientation data and measuring the fender condition of the surrounding to the sunlight in one year, obtaining a certain time step from the illuminating time and the lever solar radiation intensity of that step can be computed according to the solar altitude angle h and atmospheric translucence p. The invention can measure the solar radiation intensity of the measuring spot on the level surface, vertical surface, any dip face at a certain time and make sure the best getting-energy surface, which can be used orientate the solar collector and battery and measure the energy of the solar house and sun-breaker.

The invention provides a photovoltaic system tracking and backtracking method which comprises the following steps: a) fixedly arranging at least two photovoltaic assemblies; b) obtaining local time and latitude of a direct solar ray point, and obtaining the solar altitude angle; c) obtaining inclined plane length of each photovoltaic assembly, distance between the geometric center of the photovoltaic assembly and the horizontal plane and inclination angle, and obtaining an inclination distance of the photovoltaic assembly extending from the inclined plane top end to the horizontal plane along the bottom end direction; d) obtaining a virtual distance between an image point and a contact point of the inclination distance and the horizontal plane according to the solar altitude angle, the inclination angle and the inclination distance; e) comparing the distance between the geometric centers of the two adjacent photovoltaic assemblies and the virtual distance; and f) carrying out judgment according to the comparison data, and controlling the position relation between the photovoltaic assemblies and the solar rays through a tracker. Through the method, the solar altitude angle can be monitored, and the inclination angle of the photovoltaic assemblies is adjusted, thereby effectively preventing the adjacent photovoltaic assemblies from generating shadow in between, improving generating capacity and enlarging application range.

The invention discloses a solar tracker for water surface floating photovoltaic power generation. The solar tracker includes a plurality of floating type photovoltaic arrays arranged on water surface; photovoltaic assemblies are fixed on the floating type photovoltaic arrays; the side edge of each floating type photovoltaic array is provided with an adjustment water tank; the adjustment water tank is connected with a water pump; and the water pump is connected with a controller. According to the solar tracker of the invention, the quantity of water in the adjustment water tank can be adjusted through the water pump, so that gravity or buoyancy can be changed, the adjustment water tank drives the floating type photovoltaic array to move, so that an included angle between the plane of the photovoltaic assembly and a horizontal plane can be controlled, and therefore, the photovoltaic assembly can track solar altitude angles or solar hour angles in real time. With the solar tracker adopted, the problems of high cost and difficult maintenance brought about by electric machinery and transmission mechanisms adopted by an existing solar tracker can be solved.

The invention provides a MODIS remote sensing evaluation method for eutrophication lake algae gauss vertical distribution structural parameters. Based on field actual measurement data, a function expression and remote sensing identification method for the same for alge gauss vertical distribution are determined with a combination a alge bloom identification index NDBI and synchronous external environment factor wind speed; based on Hydrolight radiation transferring simulation, ground spectrum database of different alge gauss vertical distribution can be built; by the use of a BP neural network model, a remote sensing evaluation method for the lake algae gauss vertical distribution structural parameters based on simulation data is built; with simulation of various aerosol types, thickness, various solar altitude, satellite observation angles and azimuthal angles, a quantitative relation between ground-based simulation remote sensing reflectance ratio Rrs and a simulated Rayleigh scattering corrected Rrc is acquired; the evaluation method for the algae gauss vertical distribution structural parameters based on spectrum data simulation can be promoted to MODIS satellite image data corrected by Rayleigh scattering.

The invention provides a ground point target push-scanning imaging task parameter spaceborne solving method. The method comprises 1, building a coordinate system and defining vectors of a satellite, a ground object and the earth's core, 2, building an optical system equivalent optical path with a scanning mirror, 3, acquiring sub-satellite point solar altitude information, a satellite position and ground target information, 4, solving motion state characterization parameters of the satellite and ground target in an instantaneous inertial coordinate system, 5, calculating an expression of ground target coordinates and rate of change over time in the instantaneous inertial coordinate system, 6, calculating an expression of ground target coordinates and rate of change over time in a satellite body coordinate system and 7, building a constraint equation and calculating imaging task parameters. After acquiring ground point target coordinates, the satellite in orbit can automatically, fast and accurately adjust a scanning mirror in real time so that the scanning mirror targets an object and thus object imaging is ensured.

The invention discloses a self-maintaining photovoltaic external sunshade device with the adjustable length and angle and a regulation and control method. A sunshade photovoltaic power generation panel is mounted on a traditional external sunshade device, and multidirectional automatic regulation can be conducted according to the solar altitude and the azimuth angle, so it is guaranteed that the sunshade effect is optimal; meanwhile, energy for adjusting the sunshade photovoltaic power generation panel comes from photovoltaic power generation of the sunshade photovoltaic power generation panel. The adjustable external sunshade photovoltaic power generation panel is composed of three stretchable sunshade photovoltaic power generation panel sections, and the stretchable length of the sunshade photovoltaic power generation panel can be adjusted according to the solar radiation intensity and the sunshade requirements of residents; meanwhile, the sunshade photovoltaic power generation panel can be adjusted vertically or horizontally according to the direct solar radiation azimuth angle and the requirements for indoor sunshade effects. The optimal sunshade effect can be achieved through reasonable adjustment of the length, the horizontal angle and the vertical angle of the external sunshade photovoltaic power generation panel, and the sunshade photovoltaic power generation panel can absorb more solar heat.

A method for obtaining satellite solar angle and time on the basis of satellite orbit characteristics comprises the following steps: (1) according to the satellite sun-synchronous orbit characteristics, calculating the orbit inclination angle from the height of the satellite orbit; (2) according to the number of satellite orbits, calculating the longitude and Beijing time of sub-satellite point of the position where a satellite descending orbit intersects the equator, and converting the Beijing time into the local time so as to obtain the time of the position; (3) calculating to obtain the local times of any latitude where the satellite sub-satellite point pass; (4) according to the orbit injection error of satellite orbit inclination angle and the daily change rate of satellite orbit inclination angle during the operation process, calculating to obtain the change of satellite local time and actual local times of any latitude; (5) calculating to obtain the actual local time after satellite side-sway; (6) calculating to obtain the solar altitude, solar azimuth, and the Beijing time of an observation site. The provided method can precisely obtain the solar altitude, solar azimuth, and imaging time of a satellite according to a remote sensing satellite nominal orbit and changes thereof without knowing the satellite ephemeris data and specific imaging time.

The invention discloses an on-track space camera gain regulating method, which relates to an on-track gain regulating method of a space camera for earth observation, and aims to the solve the problems that at present, a space camera adopts a fixed gain so as to lead to overall dimming of part of images, poor image gradation, low signal to noise ratio and the like. The regulating method comprises the following steps of: before a spacecraft is launched, acquiring a gain factor corresponding to the maximal digital quantification output value of images under maximal radiance through laboratory radiometric calibration; after the spacecraft is launched, simulating the track of the spacecraft with high accuracy, and outputting the solar altitude of sub-satellite points at different shooting time; converting the solar altitude into the solar zenith angle, thereby obtaining the radiance of an entrance pupil part by an MODTRAN atmospheric radiation transfer tool when the space camera forms images of a ground feature corresponding to the maximal object reflectivity at different time; calculating gain factors of the space camera at different shooting time; combining the code values corresponding to the gain factors obtained through calculation with the shooting time into a program control instruction, and sending the program control instruction from a ground measurement and control station to the spacecraft to execute through a measurement and control antenna.

The invention discloses a comprehensive testing device for improving the thermal physical environmental performance of a heat-reflecting asphalt pavement. The device consists of an environmental control system, a data acquisition system, a test piece assembling system. According to the device, the acquisition of a structural layer temperature of the asphalt pavement under the action of solar thermal radiation can be realized, the temperature variation conditions of a pavement structure with a heat-reflecting coating and a pavement structure without the heat-reflecting coating are compared and the heat reflecting approach of the heat-reflecting asphalt pavement at different solar altitudes or angles can be measured so as to evaluate the influence of the heat-reflecting asphalt pavement on the surrounding environment. The device has the advantages of being simple in test and maintenance, convenient in data acquisition and the like.

The invention discloses an aviation image building damage detection method based on shadow and texture characteristics, and the method comprises the steps: estimating a theoretical shadow area of a building in an image through the vector data and altitude data of the building before damages and a solar altitude angle; carrying out the detection of an actual shadow in the theoretical shadow area through employing constrained color invariance; obtaining the actual shadow area of the building; obtaining the damage level of the building according to the proportional relation of the actual shadow area and the theoretical shadow area, and dividing the damage level into three levels: complete damage, general damage, and suspected intactness; detecting the top surface of the intact building through employing a vision bag-of-word model, and further judging whether the building is damaged or not. The method integrates the shadow information (height) and top surface information (texture) of the building for detection, avoids registering difficulties in conventional data fusion, and improves the detection accuracy of the damage of the building.

The invention discloses an integrally packaged type solar heat collector with combined curved surface for light collection and vacuum tube for heat collection, belonging to the technical fields of solar light collection and medium and high temperature solar heat collection. The solar heat collector of the invention comprises a combined curved surface light collector, a vacuum tube heat collector, an adjustable tracker, a packaging shell and the like. After the sun light enters the combined curved surface light collector through a transparent glass cover plate, the sun light is reflected through an inner surface of the combined curved surface light collector and collected onto the vacuum tube heat collector, the vacuum tube heat collector absorbs the sun light to generate high-temperature heat energy, and the heat energy is conducted and transmitted to users by a heat conducting working medium in the vacuum tube heat collector. The invention can collect the sun light with low energy flow density after being reflected by a plurality of curved surfaces on the vacuum tube heat collector, thus the heat conducting working medium in the vacuum tube can be quickly heated to form high-temperature heat energy. The manually adjusted tracker can adjust the orientation of the combined curved surface light collector to track the sun, thereby enabling the heat collector to keep in the optimal sun light collecting state. The invention is especially suitable for use in high-latitude areas and in winter when the solar altitude is smaller.

The invention relates to a vegetation structure parameter measurement device based on a wireless sensor network. The device is formed by the wireless sensor network and a data processing and node control system, wherein the wireless sensor network is formed by measurement nodes distributed at the upper part and the lower part of the canopy of a study area and routing nodes, and the data processing and node control system is formed by a convergent node and a control terminal remote server in a connecting way; the measurement nodes obtain vegetation parameter information through acquiring the solar radiation of the upper part and the lower part of the canopy at different solar altitudes in one day, and conducts data transmission and positioning through a wireless ad hoc network; the convergent node can upload the data of the measurement nodes to a control terminal through serial ports and GPRS, and vegetation structure parameters are computed through a data processing system; and the control terminal sends commands to the nodes through the convergent node to modify parameter setting. The invention has the advantages that the volume is small, the power consumption is low, the deployment is convenient and the cost is low, the device is suitable for large-area and long-period vegetation parameter measurement, and the practical value and the application prospect are wide in agriculture, ecology and the wireless sensor network technical field.

Method and apparatus enabling worldwide reduction of carbon dioxide emissions and / or deforestation, personal clean energy system providing for cooking and / or electricity needs, earning emission credits, monetizing values of tradable emission rights / credits accruing from emissions avoided by using the apparatus to pay for the cost of the apparatus and / or to provide ongoing revenue thereby inducing many people to substitute carbon containing fuels for cooking and / or electricity needs by a synergic combination of cooking 0 and / or electricity generation 21 on sunlight H through a low cost two-axis easy sun tracking mechanism including a bendable mirror 14 having variable curvatures rm and tilt angles sm optimized for the solar altitudes αs at the latitudes, seasons and day times from equator to arctic, resulting in greatly augmented cooking power enabling high quality meals 0 through much shorter cooking times and / or longer / higher PV cell 21 outputs charging batteries 24 powering lights, refrigerator, television, computer, enabling worldwide education and sustainable development.

The invention relates to a solar tracking device, in particular to a solar tracking device based on bionic polarized light detection. Extraction of the polarization angle and degree of polarization in an atmospheric polarization mode is achieved through polarized light detection sensors by imitating a compound eye navigation model. Firstly, a central control and information processing unit drives an actuating mechanism of a horizontal servo motor according to the included angle between the solar azimuth and polarization angle output by two polarized light sensors on a horizontal tracking physical structure unit, and then solar azimuth direction tracking is achieved; then, the central control and information processing unit controls an actuating mechanism of a vertical servo motor to rotate according to degree-of-polarization information output by two polarized light sensors on a vertical tracking physical structure unit, and then solar altitude direction tracking is achieved; finally, fine adjustment of two platforms is carried out through output of a natural light sensor. In this way, solar tracking is successfully achieved through the solar tracking device based on bionic polarized light detection.

The present invention provides a high-resolution remote sensing image building height estimation method based on a shadow. The method comprises the steps of: performing shadow detection of an originalimage to be detected, obtaining a shadow detection result map, and employing a morphological processing to obtain a more independent shadow and a shadow with more smooth edge; employing the area andthe length of the shadow and the imaging features of a satellite image to determine the direction of the shadow; determining the length of the shadow corresponding to a building through the shadow direction and the statisticals of the length of the shadow corresponding to the building; obtaining a solar azimuth through the shadow direction, and calculating a solar altitude through solar azimuth; and employing the solved shadow length and the solar altitude to estimate the height of the building. The high-resolution remote sensing image building height estimation method fully utilizes the features of the building shadow to achieve the building height estimation to effectively detect the remote sensing image building height with the shadow so as to provide effective information for remote sensing related application such as building three-dimensional reconstruction, city building historical information obtaining, city change detection.

The invention discloses an image processing-based heliostat fault diagnosis method and system. The method further comprises the following steps of: (1) acquiring images of a heliostat in the same target area to obtain at least two two-dimensional images in the same scene; (2) calculating the practical attitude data of the heliostat; (3) calculating the theoretical attitude data of the heliostat according to a solar altitude, an azimuth angle and a relative position between the heliostat and a heat absorber at an image acquiring moment; and (4) comparing the practical attitude data of the heliostat with the theoretical attitude data of the heliostat to judge whether the heliostat is faulted heliostat, wherein the step (2) further comprises the following steps of: calculating the practical attitude of a target heliostat at the same moment by using a binocular vision three-dimensional measuring algorithm; and judging the position information and the serial number of the heliostat. Due to the adoption of the method and the system, the defects of high cost and complex installation existing in the conventional close-loop fault diagnosis method are overcome; and a computer image processing technology is adopted, so that fault diagnosis of the heliostat is realized automatically, rapidly, conveniently and accurately.

The invention relates to a method for automatically updating a background in a specifically monitored video, which is used for accurately updating the changes in real time during outdoor monitoring, such as the illumination changes, the height changes of a building projection along with the sun and the shakings of tree leaves blown by wind. The method comprises the following steps of: 1) if a difference image has no changing region and then no moving target appears, ending a judgment; 2) if the changing region exists, un-determining reasons, storing a frame, acquiring the next frame, and continuously judging whether the difference image has the changing region or not, namely (1) if the changing region does not exist, considering the former change is an instantaneous light ray change, and making no response, and (2) if the changing region exists, storing the frame and reading the next frame; 3) processing the current frame in the same way, if the changing region exists, storing the current frame; 4) performing three-frame difference on the continuous three frames, if the changing region exists, considering that a target enters, otherwise, considering other reasons and making no response; and 5) selecting the latest frame to replace the original background.