333 results about "Troposphere" patented technology

The invention discloses a method for positioning a network RTK based on a star-shaped virtual reference station, which comprises the steps of: firstly, establishing a star-shaped basic calculation unit, constructing a baseline calculation way for a star-shaped VRS network RTK and proposing an ambiguity calculation method suitable for the star-shaped VRS network RTK; and then studying the algorithm of the corrections of the ionosphere and the troposphere in the VRS network RTK aiming at the star shape. The method markedly increases the calculation speed on the network ambiguity by about 50% and has higher accuracy and reliability of the generated network correction.

The present invention discloses a troposphere atmosphere delay error correction method and correction system. The method comprises the steps of (1) obtaining GNSS observation data through a GNSS foundation reinforcement system network reference stations, (2) sending the GNSS observation data to a CORS server baseline solution system, wherein the step (2) concretely comprises the steps of (a) decomposing troposphere delay into a troposphere dry component and a troposphere wet component according to the GNSS observation data and (b) carrying out regional linear interpolation model processing on the troposphere wet component to obtain a wet component correction value, and using a troposphere prior model to carry out altitude component correction of the troposphere dry component to obtain a dry component correction value, (C) combining the wet component correction value and the dry component correction value to obtain a troposphere correction value total. According to the method, the improvement of troposphere delay error correction is facilitated.

The invention relates to a positioning method for a satellite navigation enhancing system comprising such procedures as, a user station receives info from an adjacent reference station, and determines the mutually-visual satellite of the user station and the adjacent reference station, and calibrates the pseudo distance from a satellite to the user station in a time period; a reference station adjacent to the user station is used to carry out positioning resolution of the calculated pseudo distance from a plurality of satellites to the user station, so as to get the 3D coordinates of the differential positioning of the user station; the positioning result of the user is enhanced by using the final distributed area got by weighted average calculation of 3D coordinates of differential positioning of the user station and all adjacent reference stations. The invention enhances the positioning accuracy for a user by using the enhancing info from a plurality of local areas in a foundation enhancement covered area in respect to the shortcoming that the positioning accuracy is greatly reduced when the user is far from the ground station and a big difference exists between the delay error of the ground station and that of the ionized stratum and the troposphere of the user.

The invention discloses a method for eliminating delay errors of the troposphere of GNSS atmospheric probing data. The method for eliminating the delay errors of the troposphere of the GNSS atmospheric probing data is characterized in that a GPT model, a UNB3m model and a classic troposphere model are merged together, the classic troposphere model is a Hopfield or Saastamoinen model. The method for eliminating the delay errors of the troposphere of the GNSS atmospheric probing data includes the following steps that the temperature and the air pressure of a probing station are calculated out by means of the GPT model, the hydrosphere pressure of the probing station is calculated out by means of the UNB3m model and finally, a global mapping function is used for calculating out delay correction of the troposphere in the gazing direction of a satellite receiver. The method for eliminating the delay errors of the troposphere of the GNSS atmospheric probing data is capable for accurately calculating out a priori value of troposphere delay with insufficient actually measured meteorological data and can be applied to the fields such as GNSS positioning and GNSS meteorology.

The invention discloses a medium-range forecast system and method for cold, rainy and snowy weather based on atmospheric variable physical decomposition. By utilizing the atmospheric space three-dimensional multivariable and time continuous grid data outputted in the past observed, the current observed and the medium-range numerical weather prediction modes, and the physical decomposition of the climate and the weather disturbance quantity, a causality between the regional sustained low temperature, rain and snow and freezing extreme weather events and the weather disturbance prior to and during the events is established in the method. According to the invention, a physical decomposition of the climate seasonal variation field and the day-to-day weather disturbance field is carried out according to the data of day-to-day three-dimensional space grid point temperature, altitude and wind and the like of the atmosphere from the troposphere to the stratosphere in the northern hemisphere for nearly 30 years, and a database for the atmospheric climate field and the weather disturbance field can be established; and a historical database of the low temperature, rain and snow and freezing weather in south China is established according to the data of day-to-day temperature and precipitation from the national meteorological station for nearly 50 years. The invention provides not only an inquiring system for historical low temperature, rain and snow and freezing weather events, but also a forecasting system for medium-range low temperature, rain and snow and freezing weather events.

The invention discloses a common view time and frequency transmitting method based on the BeiDou navigation satellite system. According to the common view time and frequency transmitting method based on the BeiDou navigation satellite system, the time difference between the local time and the time of all tracking satellites, clock difference parameters in navigation messages, the parameters of the time delay of the ionized stratum and the time delay of the troposphere and elevation angle data are measured and extracted through a timing type BeiDou receiver, and the clock differences between the local time and tracking BeiDou satellite clocks are worked out; the difference between the local time and the time of the BeiDou navigation satellite system is worked out through preprocessing of original data and weighting of elevation angles of all the tracking satellites; the time of the navigation satellite system is used as a medium, through the short message communication function of BeiDou-1, comparison results of two common view stations are exchanged, so that the time difference of the two stations is obtained, and the relative frequency difference between the two stations is worked out. By the adoption of the technical scheme, the dependence existing when GPS is used for transmitting time can be overcome, and accurate time transmission is achieved through the BeiDou navigation satellite system; high-cost hardware support is not needed, operation is easy, long-time automatic operation can be achieved, and therefore labor cost and use cost are greatly reduced.

The invention discloses an area enhanced precision positioning service method suitable for large-scale users. According to the technical scheme, the method includes the steps that after the users effectively fix wide-lane ambiguity and L1 ambiguity of at least four satellites in a zero difference network RTK processing mode, area enhanced information of surrounding base stations does not need to be acquired, at this moment ambiguity fixed results and zenith troposphere delay residual errors acquired by interpolation are used as known truth values, received satellite UPD information is combined, and an ambiguity fixed solution in a PP-RTK mode can be immediately acquired without initialization. Due to the fact that satellite UPD, real-time satellite orbits and real-time satellite clock errors are only related to the satellites, and short-term forecast lasting tens of seconds to a few minutes can be conducted, the information can be broadcasted to the users through the communication satellites in a broadcast mode, and then real-time data communication burdens among the users and the base stations can be greatly reduced. Once user ambiguity is firstly fixed, the number of the users simultaneously serviced by an area enhanced system is no longer restricted at this moment.

The invention provides a modeling method for zenith tropospheric delay. The modeling method comprises the following steps: S11, obtaining a zenith tropospheric delay amount actually measured in each observation station; S12, calculating an annular mean value ZTDh of the zenith tropospheric delay amount corresponding to the observation station, fitting based on ZTDh to obtain an elevation correction coefficient beta and an annular mean delay amount ZTD0 naturalized to an ellipsoidal surface, corresponding to the observation station, and obtaining a single-day delay amount ZTD0(doy) after elevation correction, corresponding to the observation station according to the beta; S13, fitting based on ZTD0(doy) to obtain a period constant term A0, amplitude and initial phases A1 and d1 of an annual periodic term as well as amplitude and initial phases A2 and d2 of a semi-annual periodic term, corresponding to the observation station; S14, building a latitude and longitude grid function model based on the Chinese mainland area, and calculating based on the parameters A0, A1, d1, A2 and d2 corresponding to the observation station to obtain A0, A1, d1, A2 and d2 corresponding to each grid point in the grid function model. The modeling method is suitable for the Chinese mainland area, the precision is remarkably improved, and the overall service level of a satellite navigation positioning system of the Chinese mainland area can be improved.

A computer implemented method, apparatus, and computer program product for monitoring wind direction, speed, and turbidity. The visible sky is monitored by a set of cameras for contrails produced by a high-altitude aircraft. In response to identifying a contrail, the contrail is tracked across the field of view of the camera. Contrail data generated when the contrail is identified and during the tracking of the contrail is stored. The contrail data describes characteristics of the contrail including the spread of the contrail and the movement of the contrail across the field of view of the camera. Coordinates of the high-altitude aircraft are determined and compared with the contrail data to identify wind conditions.

The invention relates to a navigation satellite signal generator and an implementation method. The navigation satellite signal generator comprises a controller, a USBHUB, a navigation receiver, a receiving antenna, a disciplined clock module, a radio frequency module, an emitting antenna and a base band module. State self-checking is carried out on all the modules. The navigation receiver transmits information to the controller and the disciplined clock module. The disciplined clock module carries out local time service, outputs time frequency signals and transmits the time frequency signals to the radio frequency module. The controller carries out signal parameter configuration and outputs moment configuration according to ephemeris information. Pseudo-range information, Doppler information, ionosphere information, troposphere information and error information are calculated. The base band module generates intermediate-frequency signals. Base band signals are modulated through the radio frequency module, and finally radio frequency signals of multiple frequency points are synthesized into navigation satellite radio frequency signals. By means of the navigation satellite signal generator and the implementation method, navigation signals based on the real-time ephemeris can be generated and can be normal satellite signals or pesudolite signals. The navigation satellite signal generator and the implementation method can be widely used in universal receivers and can be combined with satellites in orbits for positioning.

The invention discloses a high-frequency clock error estimation method of a satellite navigation system. The method includes acquiring observed data of a tracking station; testing the reliability of the observed data; rejecting outliers from the observed data after reliability test by using linear combination of the observation quantity, determining an initial ambiguity, detecting and repairing the cycle slip, and obtaining codes and phase observed values; acquiring a satellite obit parameter, an earth polar motion parameter, a troposphere parameter and a station coordinate parameter; obtaining clock error estimated values of a satellite and a receiver according to original observed data, the satellite obit parameter, the earth polar motion parameter, the troposphere parameter and the station coordinate parameter; and interpolating the obtained clock error estimation by using the code and the phase observed value to obtain the high-frequency clock error estimation of the satellite navigation system. The method has the advantages of high reliability and accuracy and capability of improving the high-frequency clock error estimation accuracy of the satellite navigation system.

The invention discloses a multi-reference station-based network RTK (Real Time Kinematic) area atmospheric error modeling method. The method comprises the following steps of firstly, using multi-reference redundant observation information to build a multi-reference station structure-based basic resolving unit; secondly, for the multi-reference station structure-based basic resolving unit, studying an algorithm of network RTK area troposphere correction number, providing a network RTK area troposphere error modeling method which considers height difference influence and is suitable for a multi-reference station structure, and obtaining a flow station troposphere error correction value. On the basis of considering height difference, the precision and the reliability of network RTK area troposphere correction number can be obviously improved, particularly, for a low-altitude angle satellite, the precision and the reliability are higher.

The invention discloses a deception jamming signal detection method based on a single receiver. The method comprises steps: the position of a satellite after correction under an ECEF coordinate systemis acquired, satellite clock offset correction, ionosphere delay correction and troposphere delay correction are used to correct a measured pseudo range to obtain a pseudo range after correction, a least square method is used for iterative solution, the first position of a carrier under the ECEF coordinate system is obtained, and based on a pseudo range double difference model of the satellite, Taylor's approximation is carried out for iterative solution to obtain the second position of the carrier under the ECEF coordinate system; and according to whether the position offset between the first position and the second position is larger than a preset threshold, whether the currently-received signals are the deception jamming signals is judged. The detection is realized by only requiring the single receiver or a single antenna and the pseudo range measurement information, requirements on equipment are low, the algorithm is simple and efficient, the realization process is simple, and themethod is applicable to generation-type deception jamming and forward-type deception jamming.

A linear regression equation is comprised of the objective variables and the explanatory variables. The objective variables are comprised of the L1 carrier phases, the L2 carrier phases, the C / A code pseudorange, the P(Y) code pseudorange, the clock error data, the delay data of the ionosphere, and the delay data of the troposphere that related with every satellite respectively. The explanatory variables are comprised of at least the integer ambiguity and a receiver's position.The receiver's position has been linear-approximated by using the estimation results of the passed receiver's positions. Applying a least square method to the regression equation, the integer ambiguity and the receiver's position is estimated.

The present invention provides an adaptive user autonomous integrity monitoring method. The method comprises: converting the system time of different navigation systems into the same as that of the main system; converting the reference coordinates of different navigation systems to be consistent with the main coordinates; respectively estimating a satellite clock difference, a troposphere delay, an ionosphere delay, and a multipath delay; obtaining a PDOP (position dilution of precision ) value through observation data and satellite ephemeris data; when PDOP<3, using the positioning domain-based location solving method; when 3<PDOP<6, using the measurement domain-based location solving method; when 6<PDOP, determining that the system is not available; using the parity vector method for fault detection; and using the maximum likelihood estimation for fault identification. According to the method provided by the present invention, the exploitation and utilization of observation information can be maximized, and the influence of the gross error on the positioning result can be reduced, so that the performance of the autonomous integrity monitoring of a receiver can be enhanced.

The invention relates to a data processing and controlling apparatus used for a ground-based microwave radiometer. The data processing and controlling apparatus comprises a scaling module, a data quality control module, an atmosphere parameter inversion module, a derivative data product generation module and a data management module. The scaling module is used for realizing scaling operation of the ground-based microwave radiometer, and first-level brightness temperature data are obtained. The data quality control module is used for controlling the original data collected by other apparatus. The atmosphere parameter inversion module generates a troposphere temperature profile, a boundary layer temperature profile, a relative humidity and steam density profile according to the brightness temperature data after being scaled and the voltage data of each auxiliary apparatus. The derivative data product generation module performs simulation computation on the atmosphere integration steam and cloud liquid water content through the atmosphere temperature and humidity profile provided by the history sounding data, computes cloud base temperature and height, atmosphere integration steam and the cloud liquid water content. The data management module is used for realizing internal data file backup and compiling system state information and controlling management log.

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 proposes a time-series InSAR analysis method for integrating tropospheric atmospheric delay correction, thereby correcting the tropospheric atmospheric delay phase error in surface deformation monitoring of the steep mountainous terrain. In the time series InSAR data processing flow, the tropospheric atmospheric delay correction process is added and specifically, vertical stratification atmospheric delay and turbulent mixing delay are carried out. The vertical stratification atmospheric delay is estimated jointly by using a numerical meteorological model and an iterative linear phase-elevation regression model. According to the iterative linear phase-elevation regression model, a coherent point with deformation is rejected by using iterative execution of a linear phase-elevation regression model, so that only the coherent point without the deformation is kept to calculate the linear model. Therefore, the vertical stratification atmospheric delay correction in the time series InSAR analysis method is realized and thus the iterative linear phase-elevation regression model is not affected by the coherent point target without deformation, so that the interference on the mountain surface deformation signal extraction by the atmospheric delay is reduced effectively.

The invention discloses a GNSS carrier phase integral cycle ambiguity single epoch solution method. The method comprises the steps that three-frequency observation data in a Beidou satellite navigation system are used to build optimal combination observation; single epoch fixation is carried out on ultra-wide lane / wide lane and base carrier ambiguity in order; a Beidou satellite with high fixed ambiguity reliability is preferably selected to inverse atmospheric delay information; the information is used as priori information to enhance a GPS / GLONASS ionosphere-free combination ambiguity solution model; correlation between the zenith and troposphere and ambiguity parameters is reduced; the morbidity of the model is weakened; a robust estimation theory is introduced; and through the influence of the bias of a right election iterative boycott model or outliers, ambiguity single epoch accurate solution in a GPS / GLONASS dual-frequency navigation system is realized. The solution method is suitable for a short distance relative positioning mode. The advantage of the three-frequency observation data of the Beidou navigation system is used to constrain and assist the ambiguity solution of other satellite navigation systems. The robust estimation theory is introduced, which improves the reliability of ambiguity solution.

The invention discloses a method for high-precision dynamic point positioning through a big dipper double frequency receiver.Double frequency high-sampling-frequency big dipper data is utilized, only one big dipper double frequency receiver is needed, it is not required to erect a base station or a CORS system or other auxiliary devices at a known point, error sources are eliminated or weakened through algorithms, an iteration least squares elimination method is used, a kalman filter based on single difference ambiguity and troposphere delay parameters is used for parameter calculating, an accurate absolute coordinate position can be obtained, working employment is easy and convenient, the positioning precision is high, the position of a satellite is conveniently locked, and the method is suitable for large working range applications.

The invention discloses a real-time clock difference determining and forecasting method and system for a navigation satellite and a low orbit satellite. The method comprise the following steps that navigation satellite clock difference determining is conducted, real-time clock difference estimation of the navigation satellite is carried out by a slow update thread and fast update thread which usesthe slow update thread to calculate parameters of troposphere and fuzziness; navigation satellite clock difference forecasting is conducted, real-time clock error of the navigation satellite is usedfor forecasting the clock error of the navigation satellite; low orbit satellite clock difference determining is conducted, real-time clock difference of the low orbit satellite is obtained by using an obtained real time orbit, clock difference and navigation satellite clock difference forecasting data; low orbit satellite clock difference forecasting is conducted, real-time clock difference of the low orbit satellite is used for forecasting the clock difference of the low orbit satellite. The system comprises a navigation satellite clock difference determining module, a navigation satellite clock difference forecasting module, low orbit satellite clock difference determining module and a low orbit satellite clock difference forecasting module. Estimation and prediction accuracy of real-time precise clock difference of the high orbit navigation satellite and low orbit satellite are improved.

The invention belongs to the technical field of remote sensing data application technology, and relates to a near-surface nitrogen dioxide concentration estimation method based on a Stacking integrated model, which comprises the following steps: acquiring actual NO2 concentration data, meteorological monitoring data, geographic data and population data of a monitoring station; acquiring satellite remote sensing data of NO2 troposphere column concentration and verifying the satellite remote sensing data; performing data cleaning, averaging actual NO2 concentration data of a monitoring station and NO2 troposphere column concentration satellite remote sensing data in a gridding mode and matched with meteorological monitoring data, and constructing an NO2 data set; performing modeling based on the NO2 data set, three models of GA-RF, GA-GBRT and GA-XGBoost are adopted as base learners, ridge regression is adopted as a meta learner for fusion, and obtaining a Stacking integrated model; and carrying out simulation estimation on the near-surface NO2 concentration by utilizing the Stacking integrated model to obtain the near-surface NO2 concentration. Through the combination of various machine learning algorithms, the defects of a single model are overcome, the input of linear regression is optimized, and the overall performance of the model is improved.

The invention discloses a CORS reference station network baseline ambiguity resolving method considering a troposphere influence. The method is characterized by through dual-frequency data collected by a geodesic receiver, establishing a GNSS double difference observation equation; using a real distance from a satellite to the receiver to carry out detection and repairing of cycle slip; through using a MW combination observation value, carrying out solving and verification of wide-lane ambiguity; through writing troposphere delay errors of two ends of a baseline into a product of a projection function and site zenith troposphere delay, establishing a Kalman filtering observation equation and establishing a Kalman filtering state equation; through smoothing a Kalman filter, filtering a floating point value of L1 integer cycle ambiguity; searching the L1 integer cycle ambiguity floating point value acquired through the Kalman filtering; and verifying the searched L1 integer cycle ambiguity. In the invention, a characteristic that a base station coordinate in a network RTK is accurate and known is fully used, high precision is possessed and small cycle slip can be detected and repaired.

The invention discloses a landslide monitoring method and a monitoring system applying the same. A mountain body movement state is monitored in a mode of creatively combining a tilt sensor and GPS / Beidou differential positioning, and accurate original data is provided for landslide judgment and early warning. The GPS / Beidou-based differential positioning method is applied to monitoring landslide mass, position data of a plurality of monitoring points of a mountain body is monitored, fixed errors of satellite clock, satellite ephemeris, ionized layer time delay and troposphere time delay and the like are eliminated, and the GPS / Beidou positional accuracy is greatly improved.

The invention discloses a correcting method for global satellite navigation system troposphere zenith delay, and relates to correcting technologies for troposphere zenith delay of radio signals in satellite navigation application. The method includes the following steps that (1), a global troposphere zenith delay original data base is built; (2), a global troposphere zenith delay data base is built; (3), a reseau and global troposphere zenith delay simplifying data base is built; (4), the annual mean value and annual variation amplitude of the troposphere zenith delay are calculated; (5), a global troposphere zenith delay correcting parameter table is stored; (6), the troposphere zenith delay is corrected through a receiver end. The correcting method for the global satellite navigation system troposphere zenith delay has the advantage that elaborate space and time changes of the global troposphere zenith delay are fully considered, simple calculation formulas and a reasonably optimized space reseau and parameter table storing method are adopted, so that the correcting method has the advantages of being high in accuracy, easy and convenient in calculation and high in efficiency, and meanwhile requirements for storing space of the receiver end are lowered.

The invention discloses a sparse reference station network zenith troposphere delay modeling method considering the elevation difference. Conventional local area network enhancement PPP (precise point position) modeling methods do not consider effects caused by the elevation difference on the interpolation accuracy and depend on a certain amount of reference stations. According to the method, the relation between the elevation difference and zenith troposphere delay is considered, reference station zenith troposphere wet delay values are calculated through non-ionosphere combined precise point filtering, zenith troposphere dry delay values are calculated through a model, the dry (wet) delay values are divided into an elevation strong correlation part and an elevation weak correlation part according to the relation between the troposphere delay values and elevation factors, and the sparse reference station network zenith troposphere delay modeling method considering the elevation difference is provided on the basis. The method considers the effects caused by the elevation difference on the troposphere delay values, is applicable to sparse reference station local area networks and is low in dependence on the number of the reference stations.

A network RTK solution method according to the invention comprises a first step of joint solution of the baseline involved in a GNSS network and atmosphere (ionosphere and troposphere) model parameters according to a scale factor of the atmosphere (ionosphere and troposphere); a second step of floating point ambiguity closed loop constraint; a third step of integer double-difference ambiguity searching; a fourth step of integer ambiguity closed loop check; a fifth step of integer ambiguity constraint, solving of the atmosphere (ionosphere and troposphere) model parameters, and solving, by using the constrained integer ambiguity, of a new scale factor of the atmosphere (ionosphere and troposphere) for the use in the next epoch (feedback to the first step); and a sixth step of generation of VRS observation data and the like. The network RTK solution method of the invention can improve the accuracy and reliability of the baseline double-difference integer ambiguity fixing in the network RTK and solve the problem that the fixing rate of the baseline ambiguity in some areas is not high which leads to the decline of the network RTK performance.

The invention discloses a novel method for calculating local zenith tropospheric moisture delay by using meteorological data and belongs to the technical field of space geodetic surveying. The novel method is characterized in that meteorological parameters of daily weighted average temperature, vapor direct-attenuation factors and the like are acquired by calculation according to historical vertical profile meteorological data of the area to be calculated and specifically includes: calculating the vertical profile temperature value of the time to be calculated; building a water vapor pressureattenuation module and calculating the vertical profile vapor pressure of the time to be calculated; calculating the average weighted temperature; calculating the vapor direct-attenuation factors; calculating the daily tropospheric moisture delay. The variation characteristics of the meteorological parameters affecting the troposphere moisture delay are studied deeply; parameters of temperature, air pressure, vapor pressure and the like can be easily acquired according to the earth's surface, the tropospheric moisture delay of the area is calculated accurately, and high precision is achieved as compared by using a current global tropospheric delay model.

The invention discloses a method for multiplying positioning precision in a satellite navigation positioning system. In the method, each navigational satellite in the satellite navigation positioning system downloads pseudo stochastic noise codes, navigation messages, and wide-area enhanced information via multiple carrier frequency points; a user terminal measures and corrects the track errors of the navigational satellites, ionosphere time delay, troposphere time delay, and multipath errors simultaneously and individually with the multiple carrier frequency points in order to achieve pseudo range measurement between the navigational satellites and the user terminal on the multiple carrier frequency points; and by using a pseudo range observational equation of the multiple carrier frequency points, the accurate coordinate of the position of the user terminal can be calculated via iterative computations. The method is capable of well increasing the positioning precision of the user terminal and substantially improving the navigation positioning performance of the satellite navigation positioning system.