12 results about "Occultation" patented technology

The invention provides an occultation constellation observation system simulation and forecast capability evaluation method, which comprises the following steps of: simulating and calculating an atmospheric refractive index by using a GNSS (Global Navigation Satellite System) radio occultation refractive index observation operator; simulating and calculating a one-dimensional bending angle by using a GNSS radio occultation one-dimensional bending angle observation operator; simulating and calculating a two-dimensional bending angle by using a GNSS radio occultation two-dimensional bending angle observation operator; correcting the bending angle of the L2 frequency on the basis of the difference between the bending angles of the L1 and L2 frequencies; and completing quality control of occultation observation data based on the atmospheric refractive index, the one-dimensional bending angle, the two-dimensional bending angle, the corrected bending angle of the L2 frequency and the actually collected occultation observation data, wherein the atmospheric refractive index, the one-dimensional bending angle and the two-dimensional bending angle are calculated through simulation. By establishing the error evaluation model for the autonomous occultation constellation observation data, the assimilation application effect of the autonomous occultation constellation observation data in the numerical weather forecasting system can be optimized, and direct technology and experience can be provided for business operation of future observation data in the numerical weather forecasting system.

The invention discloses an elevation correction method and device for occultation ZTD data and an application system, and the method comprises the steps: obtaining occultation data of a target area, and determining a corresponding year product day and an occultation ZTD value before correction according to the occultation data; matching the occultation point spatial position of the occultation data with the grid point of the ERA5 data, and determining a target grid point; determining ZTD elevation scaling factors corresponding to the annual day and the target grid point by using a pre-constructed ZTD elevation scaling factor model according to the annual day; according to the ZTD elevation scaling factor and the conversion relation between the uncorrected occultation ZTD value and the corrected occultation ZTD value, the uncorrected occultation ZTD value is corrected to the target elevation position, and the corrected occultation ZTD value is obtained. By correcting the occultation ZTD value before correction to the target elevation according to the corresponding ZTD elevation scaling factor, the problem that the ZTD value error is large due to the fact that the earth surface part of occultation data is missing can be effectively solved, and the occultation ZTD data precision is improved.

The invention discloses a GNSS occultation open-loop forecasting method based on a cubic spline interpolation algorithm, and relates to the field of occultation open-loop forecasting. The method comprises the following steps: judging whether a current navigational star is atmospheric occultation or not through an occultation event forecasting algorithm; acquiring position and speed information of atmospheric occultation and a low earth orbit; carrying out occultation forecast calculation on atmospheric occultation by adopting an atmospheric model to obtain model Doppler caused by satellite motion and model pseudo-range caused by neutral atmosphere; the method comprises the following steps: caching n-second model Doppler, model pseudo-range and open-loop forecast time of occultation in a 1HZ task, and obtaining interpolation parameters of the model Doppler and the model pseudo-range by using cubic spline interpolation; through the interpolation parameters, carrying out interpolation to obtain a 100HZ model Doppler and a 100HZ model pseudo-range; through the model pseudo-range, signal emission time is obtained through calculation; through signal emission time of a 100HZ task period, a signal emission time deviation value is obtained through calculation and converted into a hardware adjustment count, and the hardware adjustment count is transmitted into FGPA adjustment so as to carry out open-loop tracking of atmospheric occultation.

This application discloses a one-dimensional variational inversion method and apparatus for GNSS occultation data. The method includes background field preparation: interpolating temperature, air pressure, and water vapor pressure from the grid field to the latitude and longitude of the occultation data; simultaneously, interpolating the liquid water content and ice water content in the clouds to the latitude and longitude of the occultation data to obtain the background field profile required for inversion; and inputting observation data and background field: inputting the occultation data, background field profile, observation error covariance matrix, and background field error covariance matrix into the one-dimensional variational inversion system. By adding liquid water content and ice water content terms to the observation operator, the deviation between the observation data and the background field data is calculated, and the distribution characteristics of the deviation are statistically analyzed. After adding liquid water and ice water, the average refractive index deviation between the two types of data is significantly reduced.

The application provides a GNSS interference detection method and system based on AGC gain of a spaceborne GNSS occultation detector, the method comprising: reading AGC gain data and LEO satellite position data; time matching the AGC gain data and the LEO satellite position data; determining AGC gain under a condition without GNSS interference; calculating an AGC gain difference sequence; and performing GNSS interference detection on the AGC gain difference sequence based on a set GNSS interference detection threshold. The application has the advantages that it is suitable for a spaceborne GNSS occultation detector, and provides an effective solution for GNSS interference detection based on observation of the spaceborne GNSS occultation detector, which is simple, effective and easy to implement.

The present invention discloses a method and system for spatio-temporal data analysis of occultation data. The method includes: acquiring the spatio-temporal data of occultation data, where the spatio-temporal data includes: the time when the occultation event occurs, and the geodetic longitude, latitude, and altitude of the occultation tangent point; dividing the Earth's surface into uniform grids in space; according to the spatio-temporal data of the occultation event, projecting and accumulating the occultation events into the corresponding grids in sequence according to the chronological order of their occurrence, to obtain the occultation spatio-temporal data divided by grids; according to the occultation spatio-temporal data divided by grids, calculating the number of occultation events and its spatio-temporal distribution data, where the spatio-temporal distribution data includes: global coverage rate and global uniform coverage index; according to the number of occultations and its spatio-temporal distribution data, drawing a global coverage situation diagram of occultation events and the trend diagrams of the number and coverage rate changing with time, and conducting analysis on the coverage rate, uniformity, and timeliness of occultation events in specific time periods and specific regions.

The invention relates to a pose measurement and control method of a distributed external shielding planet observation system, and belongs to the field of space astronomical telescopes. The method comprises the following steps: performing primary satellite and secondary satellite formation setting on a telescope; performing relative translation coarse alignment on the primary satellite and the secondary satellite; performing focal length precise adjustment on the primary satellite and the secondary satellite; performing three-dimensional attitude precise alignment on the primary satellite and the secondary satellite; the star shielding cover is arranged between the telescope and the interference fixed star, and the positions and poses of the star shielding cover and the telescope are adjusted. According to the invention, micron-level relative attitude determination and synchronization, centimeter-level formation flight control and arc-second-level measurement resolution can be realized.

The present invention relates to an atmospheric density tomography scanning detection method, a computer device and a storage medium. The method comprises: constructing a forward model of the energy spectrum of the astronomical X-ray source in the process of the earth's atmospheric occultation based on the detector response matrix of the X-ray satellite calibration database, the X-ray cross section of the earth's atmospheric components calculated by using the XCOM database, the energy spectrum of the celestial X-ray source obtained by Xspec fitting, and the atmospheric density basis function provided by the NRLMSIS 2.0 model; constructing a likelihood function between the hypothesis and the actual measurement under Poisson statistics based on the X-ray satellite measured energy spectrum data with a sufficiently high signal-to-noise ratio and vertical resolution obtained by satellite platform processing; and fitting the observed energy spectrum and the model energy spectrum using a Markov chain Monte Carlo algorithm (MCMC) based on the Bayesian theorem and Bayesian estimation, thereby realizing the inversion of the atmospheric density in the near-space of the earth. The method can overcome the defects of the poor spatial coverage of the existing detection means and the difficulty in realizing global measurement.

The invention relates to the technical field of occultation observation, and discloses an occultation atmospheric bending angle observation error confirmation method. The confirmation method comprises the following steps: obtaining an occultation atmospheric bending angle in occultation data, and a first meteorological data set and a second meteorological data set which correspond to an occultation profile in the occultation data and are not derived from the current occultation; determining a first atmospheric bending angle according to the first meteorological data set, and determining a second atmospheric bending angle according to the second meteorological data set; obtaining a first bending angle error between the occultation atmospheric bending angle and the first atmospheric bending angle, a second bending angle error between the occultation atmospheric bending angle and the second atmospheric bending angle, and a third bending angle error between the first atmospheric bending angle and the second atmospheric bending angle; and determining obscuration atmospheric bending angle observation errors through a formula. By adopting the confirmation method, the objectivity of the observation error can be improved. The invention further discloses a device for confirming the obscuration atmospheric bending angle observation error and a using method.

The application relates to the technical field of occultation observation, and discloses a method for confirming an observation error of an occultation atmospheric bending angle. The method comprises the following steps: obtaining an occultation atmospheric bending angle in occultation data, and first and second meteorological data sets corresponding to an occultation profile in the occultation data and not derived from a current occultation; determining a first atmospheric bending angle according to the first meteorological data set, and determining a second atmospheric bending angle according to the second meteorological data set; obtaining a first bending angle error of the occultation atmospheric bending angle and the first atmospheric bending angle, a second bending angle error of the occultation atmospheric bending angle and the second atmospheric bending angle, and a third bending angle error of the first atmospheric bending angle and the second atmospheric bending angle; and determining the observation error of the occultation atmospheric bending angle through a formula. The method can improve the objectivity of the observation error. The application also discloses a device for confirming the observation error of the occultation atmospheric bending angle and a use method.

The invention discloses an autonomous navigation method based on the atmospheric absorption effect of an X-ray source, and belongs to the technical field of autonomous navigation of aircrafts. The method comprises the following steps: firstly, establishing a relation model of the tangency point height and the X-ray atmospheric transmittance in an occultation observation state, then calculating the X-ray atmospheric transmittance at the current moment to obtain the corresponding tangency point height, and combining the predicted speed and position information of the aircraft at the current moment, and carrying out information fusion through Kalman filtering to realize autonomous navigation of the aircraft. The X-ray pulsar navigation detector is used for detecting strong-flow X-ray sources including pulsar and direct-flow X-ray stars, the defect that the number of strong sources in X-ray pulsar navigation is insufficient is overcome, the number of navigation sources is increased, and the precision and real-time performance of X-ray pulsar navigation are improved.

The invention provides a GNSS interference detection method and system based on AGC gain of a satellite-borne GNSS occultation detector. The method comprises the following steps: reading AGC gain data and LEO satellite position data; performing time matching on the AGC gain data and the LEO satellite position data; determining an AGC gain under the condition of no GNSS interference; calculating an AGC gain difference value sequence; and performing GNSS interference detection on the AGC gain difference value sequence based on a set GNSS interference detection threshold value. The method has the advantages that the method is suitable for the satellite-borne GNSS occultation detector, an effective solution is provided for carrying out GNSS interference detection based on the observed quantity of the satellite-borne GNSS occultation detector, and the method is simple, effective and convenient to implement.