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    16 July 2015, Volume 44 Issue 增刊
    Syntactic Characteristics and a Smart Construction Mechanism for Thematic Map Symbols
    ZHAO Fei,Du Qingyun,REN Fu,WANG Guizhi
    2015, 44(增刊):  0. 
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    The construction of thematic map symbols is a very complex and intellectually demanding process, but thematic symbols can be automatically generated and easily shared on the web using the syntactic structure of semantic symbols. In this paper, the symbol types, inner structure, and design pattern are discussed. A syntactic construction theory based on letter (thematic maps primitive) - word (single thematic symbol) - sentence (combined symbols or complex symbols) structure model is proposed to automate the construction of thematic map symbols. As a result of this research, symbols can be defined using cartographic primitives which are arranged according to syntactic principles. A semiotic model and word-centered construction theory can be integrated into interactive cartography as represented by the technology of Internet. Finally, the concepts and schema of this theory are discussed, and some examples are presented based a web thematic cartographic system to verify its utility.

    Complex Least Squares Adjustment to Improve Tree Height Inversion Problem in PolInSAR
    ZHU Jianjun, XIE Qinghua, ZUO Tingying, WANG Changcheng, XIE Jian
    2015, 44(增刊):  0. 
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    At present, the principal data processing methods involving complex observations are based on two strategies according to characteristics of the observation process, i.e., step-by-step and direct resolution. However, these strategies have some limitations, e.g. they cannot consider statistical observation error information, redundant observations and so on. This paper applies least squares methods to complex data processing to extend surveying adjustment theory from real to complex number space. We compared the two adjustment criteria for a complex domain in a quantitative way. In order to understand the effectiveness of complex least squares, tree height inversion from PolInSAR data is taken as an example. We firstly established both a complex adjustment function model and a stochastic model for PolInSAR tree height inversion, and then applied the complex least squares method to estimate tree height. Results show that the complex least squares approach is reliable and outperforms other classic tree height retrieval methods; the method is simple and easy to implement.

    Short-term Prediction of Ionospheric TEC Based on ARIMA Model
    REN Xiaodong,WU Fengbo,ZHANG Xiaohong
    2015, 44(增刊):  0. 
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    In order to achieve high short-term prediction accuracy of Ionospheric TEC, first, we transform a seasonal time series for ionospheric Total Electron Content (TEC) into a stationary time series by seasonal differences and regular differences with a full consideration of the Multiplicative Seasonal model. Next, we use the Autoregressive Integrated Moving Average (ARIMA) model taken from time series analysis theory for modeling the stationary TEC values to predict the TEC series. Using TEC data from 2008 to 2012 provided by the Center for Orbit Determination in Europe (CODE) as sample data, we analyzed the precision of this method for prediction of ionospheric TEC values which vary from high to low latitudes during both quiet and active ionospheric periods. The effect of the TEC sample’s length on the predicted accuracy is analyzed, too. Results from numerical experiments show that during the ionospheric quiet period the average relative prediction accuracy for a six day time span reaches up to 83.3% with average prediction residual errors of about 0.18±1.9TECu. During ionospheric active periods it changes to 86.6% with an average prediction residual error of about 0.69±2.6TECu. For the quiet periods, above 90% of predicted residual is less than ±3TECu while during active periods, it is only about 81%. The two periods show that that the higher the latitude, the higher the absolute precision, and the lower the predicted relative accuracy. In addition, the results show that prediction accuracy will improve with an increase of the TEC sample sequences length, but it will gradually reduce if the length exceeds the optimal length, about 30 days. On the other hand, with the same TEC sample, as the predicted days increase, the predictive accuracy decreases. Athough the predictive accuracy is not apparent at the beginning, it will be significantly reduced after 30 days.

    Colored Noise Identification and Compensation Based on the Continuous Adjustment Model
    XUE Shuqiang,YANG Yuanxi
    2015, 44(增刊):  0. 
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    Colored noises must be taken into account in adjustment models. As useful signals, these colored noises must be accurately identified and extracted by signal analysis techniques. A continuous adjustment model is introduced with respect to colored noises, and then generalized from finite space to infinite space, the so called as Hilbert space. This extension provides a new technique to perform continuous observational system design, Fourier analysis, as well as parameter estimation. Optimization and diagnosis on the continuous adjustment model was performed by maximizing the Gramer’s determinant. Related to the definition of the integral, a least squares solution for the continuous adjustment model was treated as a limit case for the discrete least squares problem with infinite observations. The influence caused by colored noises is systematic, but it can be eliminated or compensated by optimally designing the observational system.

    Comparison between Plane and Stereo Block Adjustment For ZY-3 Satellite Images
    WANG Taoyang; ZHANG Guo; LI Deren ; JIANG Wanshou; TANG Xinming; LIU Xue
    2015, 44(增刊):  0. 
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    Block adjustment for satellite images cannot be solved with weak convergence geometric conditions, therefore a plane block adjustment method to improve the targeting precision of images is proposed utilizing DEM as height constraint plane block adjustment method. First, a rational function mode lwith affine transformation is selected as the mathematical model of the satellite image plane block adjustment. Second, to update the ground coordinates of tie points(TPs), the plane coordinates of TPs are only solved in the adjustment process. Elevation values are obtained by using DEM interpolation. Finally, the plane coordinates of all TPs and orientation parameters of all satellite images are solved through plane block adjustment with a few ground control points ZY-3 nadir images for two regions are tested for plane block adjustment while ZY-3 forward-nadir-back images of the same two regions are tested for stereo block adjustment. A comparison indicates that almost the same accuracy can be obtained with plane block adjustment support using a 1:50 000 DEM and stereo block adjustment for ZY-3 images. For ZY-3 nadir images, almost no loss of plane block adjustment accuracy occurred when global DEM with 1 km grid and SRTM with 90 m grid replaced the 1:50 000 DEM as elevation control, . Test results demonstrate the effectiveness and feasibility of the plane block adjustment method.

    A 16-parameter GEO Broadcast Ephemeris
    ZHANG Zhongkai, DU Lan, LIU Li, HE Feng, LU Yu, ZHOU Peiyuan
    2015, 44(增刊):  0. 
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    Currently, the broadcast ephemerides used in GEOs are same as those of the MEOs and IGSOs in the BeiDou navigation constellation. However, a trade-off strategy, i.e. an orbital inclination of 5? rotation, is needed in the fitting algorithm to solve the ephemeris parameters as well as the user satellite position computation for GEOs. Based on the standard broadcast ephemerides, the representations of both the orbit and its perturbation were revised according to the second class of nonsingular orbital elements. In this research, a 16-parameter broadcast ephemeris is presented specifically for GEOs,and user satellite position computation formulas were derived correspondingly. Fit simulations show that the root of mean squares (RMS) of user range error (URE) with two hour and three hour data sets are better than 0.05 m and 0.1 m, respectively.

    A Fast Aerial Image Matching Method Using Airborne LiDAR Point Cloud and POS Data
    ZHANG Yongjun, XIONG Xiaodong, WANG Mengqiu, LU Yihui
    2015, 44(增刊):  0. 
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    A novel tie point matching algorithm orf aerial images with the assistance of airborne LiDAR point clouds and POS data is proposed in this paper. Firstly, the conjugate point searching strategy used in traditional correlation coefficient matching is improved and a fast algorithm is presented. Secondly, an automatic camera boresight misalignment calibration method based on virtual ground control points is proposed, and then the searching range of image matching is adaptively determined and applied to the image matching of the entire surveying area. Test results verified that the fast correlation coefficient matching algorithm proposed in this paper can reduce approximately 25% of the matching time without the loss of matching accuracy. The camera boresight misalignment calibration method can effectively increase the accuracy of exterior orientation elements of images calculated from POS data, and thus can significantly improve the predicted position of conjugate point for tie point matching. Our proposed image matching algorithm can achieve surperior matching accuracy with multi-scale, multi-view, and cross-flight aerial images.