Subjects: Geosciences >> Space Physics submitted time 2017-01-22
Abstract： With the increase of explored data, in order to improve data display result and efficiency, reasonable data arrangement is needed. In this paper, based on the solar wind data characteristics, the SDOG-R grid which is radial independent division in the adaptive SDOG grid is mainly elaborated. In order to make data applicable to the model, a centroid interpolation algorithm based on three-dimensional spherical coordinate system is proposed to re-sample the original data. The division model not only applies to both regular and irregular sampling data, but also maintains the characteristics of original data to the best and encodes grids with improved CDZ curve. The model not only resolves the problem that grids at the two poles and the center of the sphere are too dense, but also resolves the problem that radial resolution is greater than spherical resolution. Keywords: solar wind; space subdivision; SDOG-R;encoding
Peer Review Status:
Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2017-01-22
Abstract： With the massive increase of space exploration data, in order to improve the visibility effect and data access efficiency, effective organization and management is needed. In this paper, based on the existing 2D subdivision models, combined with the solar wind data characteristics, for the ecliptic plane and meridian plane which are over the sun centroid, a new model, applicable to solar wind data, is put forward, PDQG, namely plane degradation quad-tree grid. Based on improved degradation Z curve Grids, encoding scheme of grids is given. The model not only resolves the problem that grids near to heliocentric are too dense, but also meets the requirement that resolution in radius is not equal to that in longitude and latitude, provides hierarchical multi-resolution data. It can support the organization and management of massive space data effectively.
Peer Review Status:Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2017-01-22
Abstract： In sky coverage analysis, we present an efficient algorithm based on a coordinate transformation method to calculate the points on the boundary of detection field. In this method, the complexity of coordinates transformation is reduced by building a new Celestial Coordinates. Based on this algorithm, QTM, a coding method that has many advantages can be used to manage the data calculated. The main contents of this topic include: to build the quantitative calculation model for sky coverage; to establish the rasterized expression method of sky coverage analysis results; and to verify the method, analyse the accuracy of the method, compare the efficiency with the attitude-matrix transformation method and analytical method.
Peer Review Status:Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-13
Abstract： So far the analysis method of detective coverage in multipoint coupling plasma detective missions on space processes is still at the stage of qualitative analysis. Statistical analysis of a certain space region for the satellites also cannot undergo further quantitative analysis. To meet the needs of fast development of space science missions, on the basis of correlation function and space processes analysis, a coverage analysis method based on theta-tR coverage diagram is proposed. By analysis of theta-tR coverage diagram in accumulative time period of various design alternative, the appropriate design can be chosen according to the characteristics of coverage range. Then quantitative analysis is made on multipoint coupling detective processes of two coplanar elliptic orbits, with which the method is verified.
Peer Review Status:Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-13
Abstract： In sky coverage analysis, we present an efficient algorithm based on a coordinate transformation method to calculate the points on the boundary of detection field. In this method, the complexity of coordinates transformation is reduced by building a new Celestial Coordinates. Based on this algorithm, QTM, a coding method that has many advantages can be used to manage the data calculated. The main contents of this topic include: to build the quantitative calculation model for sky coverage;to establish the rasterized expression method of sky coverage analysis results;and to verify the method, analyse the accuracy of the method, compare the efficiency with the attitude-matrix transformation method and analytical method.
Peer Review Status:Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-04
Abstract： Two-dimensional coupled optics swing mirror is a core module in an infrared optical scanning system of space, which demands special requirements of high precision and decoupling movement in a servo control system. A novel decoupling strategy called coupled offset compensation and segmentation stepping method was proposed based on accurate system modeling, abundant simulating and analysis results. The proposed servo control system of optics swing mirror was mainly constructed with a DSP chip, high precision brushless resolvers and limited angle brushless torque motors, which adopted position feedback and velocity feedback by PID algorithm. The experimental results indicate that the novel decoupling strategies are correct and that the servo control system makes the swing mirror achieve high precision movement which has a good dynamic characteristics, short response time and small overshoot. The method applied to the servo control system can be widely used in the field of high-precision swing scanning control system and possesses a great application prospect.
Peer Review Status:Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-04
Abstract： In order to choose the best detection efficiency of different formations, quantitative evaluation of different formations shall be employed. In this paper, the existing evaluation parameters of four-point cooperative detection are analyzed and summarized and then based on the definition of volumetric tensor, the five-point formation is divided into five tetrahedrons and one main tetrahedron plus a fifth point to evaluate the detection efficiency. Finally, orbit data of five-spacecraft in one orbit period is used to simulate and analyze the two methods, and result shows that the method works well in evaluating five-point formation.
Peer Review Status:Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-04
Abstract： Adjacency effect of the optical remote sensing could be regarded as the convolution of the atmospheric point spread function(PSF) and the surface-leaving radiance. By simulating the atmospheric PSF with backward Monte Carlo method and calculating the surface-leaving radiance with MODTRAN model,the at-sensor radiance was obtained. The adjacency effects for different target and background under different propagation conditions were simulated and analyzed. The results show that target and background reflectivity affect adjacency effect significantly and the percentage of the radiance caused by the adjacency effect in the total radiance increases with the increase of the background reflectivity. Adjacency effect for dark target under bright background is more obvious than that for bright target under dark background. Given imaging height and area, the higher the imaging space resolution, the stronger the adjacency effect is. Effect of the surface meteorological range on adjacency effect is of high importance. The larger the surface meteorological range, the bigger the sun zenith angle, the weaker the adjacency effect is. These results could provide the basis for modeling the optical remote sensing imaging system with high precision and exploring the correction algorithm of the adjacency effect.
Peer Review Status:Awaiting Review
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