遗传算法在组分温度反演中的应用

介绍了遗传算法的主要内容和工作原理。在连续植被热辐射方向性模型的基础上,从热红外多角度遥感数据中,同时反演混合像元组分温度、土壤比辐射率以及叶面积指数。大量试验表明,利用遗传算法反演组分温度效果非常好。在宽松的先验知识条件下,该方法可以解决不确定性反演问题     

Error analysis of the 3D similarity coordinate transformation

The 3D similarity coordinate transformation with the Gauss–Helmert error model is investigated. The first-order error analysis of an analytical least-squares solution to this problem is developed in detail. While additive errors are assumed in the translation and scale estimates, a 3 × 1 multiplicative error vector is defined to effectively parameterize the rotation matrix estimation error. The propagation of the errors in the coordinate measurements to the errors in the estimated transformation parameters is derived step-by-step, and the formulae for calculating the variance–covariance matrix of the estimated parameters are presented.     

基于交互多模型的水下目标跟踪方法

According to the requirements of real-time performance and reliability in underwater maneuvering target tracking as well as clarifying motion features of the underwater target, an interacting multiple model algorithm based on fuzzy logic inference （FIMM） is proposed. Maneuvering patterns of the target are represented by model sets, including the constant velocity model （CA）, the Singer mode~, and the nearly constant speed horizontal-turn model （HT） in FIMM technology. The simulation results show that compared to conventional IMM, the reliability and real-time performance of underwater target tracking can be improved by FIMM algorithm.     

Applications of Lodrigues Matrix in 3D Coordinate Transformation

Three transformation models (Bursa-Wolf, Molodensky, and WTUSM) are generally used between two data systems transformation. The linear models are used when the rotation angles are small; however, when the rotation angles get bigger, model errors will be produced. In this paper, we present a method with three main terms: ① the traditional rotation angles θ , φ ,ψ are substituted with a , b, c which are three re-spective values in the anti-symmetrical or Lodrigues matrix; ② directly and accurately calculating the formula of seven parameters in any value of rotation angles; and ③ a corresponding adjustment model is established. This method does not use the triangle function. Instead it uses addition, subtraction, multiplication and division, and the complexity of the equation is reduced, making the calculation easy and quick.     

Small-world characteristics on transportation networks: a perspective from network autocorrelation

Studies on small-world networks have received intensive interdisciplinary attention during the past several years. It is well-known among researchers that a small-world network is often characterized by high connectivity and clustering, but so far there exist few effective approaches to evaluate small-world properties, especially for spatial networks. This paper proposes a method to examine the small-world properties of spatial networks from the perspective of network autocorrelation. Two network autocorrelation statistics, Moran’s I and Getis–Ord’s G, are used to monitor the structural properties of networks in a process of “rewiring” networks from a regular to a random network. We discovered that Moran’s I and Getis–Ord’s G tend to converge and have relatively low values when properties of small-world networks emerge. Three transportation networks at the national, metropolitan, and intra-city levels are analyzed using this approach. It is found that spatial networks at these three scales possess small-world properties when the correlation lag distances reach certain thresholds, implying that the manifestation of small-world phenomena result from the interplay between the network structure and the dynamics taking place on the network.      

面向多层次公众认知需求的土地利用规划信息重构模型

针对规划公示信息的多层次公众认知需求,利用本体思想解析土地利用规划信息,构建有向图为框架的信息重构模型;设计模型要素的关系数据结构,实现基于图遍历的信息检索与语义表达算法。以海南省昌江黎族自治县土地利用总体规划成果(2006～2020年)为实例,验证了模型的有效性。     

四川大巴山国家地质公园地质遗迹景观数据库平台构建

本文以四川大巴山国家地质公园为例,研究并构建了一套面向地质遗迹资源管理和景观规划辅助为主要目标的数据库管理综合平台.参照《中国国家地质公园建设技术要求和工作指南》(2002),建立了适合研究区地质遗迹景观的分类体系、编码规则和数据库.设计开发了基于SOA的数据库管理平台架构,并通过网络门户集成各项服务.经投入运行表明,...     

Orthorectification of IKONOS and impact of different resolution DEM

IKONOS image has been wildly used in city planning, precision agriculture and emergence response. However, the accuracy of IKONOS Geo product is limited due to distortion caused by terrain relief. Orthorectification was performed to remove the distortion and the impact of different DEM on orthorectification were evaluated. 38 ground control points （GCPs） and 25 independent check points （ICPs） were collected. DEMs were generated from 1 ： 10 000 and 1 ： 50 000 topographic maps. Results show that RMS error at the check points is 1. 554 0 m using DEM generated from 1 ： 10 000 topographic map, which can meet the accuracy requirement of IKONOS Precision product （1.9 m RMSE）. While RMS error is 2. 572 4 m using DEM generated from 1 ： 50 000 topographic map.     

Observation on height changes of chinese tide gauges by GPS

IntroductionBecause of global temperature rising and glacierthawing,the sea level has risen about 10-25 cmin the past century[1]. The sea level change isone of the main ai ms in global change monito-ring. Presently the basic tool used in sea levelmonitori…     

自适应卡尔曼滤波在GPS/DR组合导航中的应用

针对在观测条件较差的情况下卡尔曼滤波的鲁棒性较差,本文设计了一种自适应卡尔曼滤波模型。通过实际车载GPS/DR组合导航试验,结果表明该模型在观测质量较差的情况下能够抑制较大的偏差,相对于标准卡尔曼滤波模型,其平面定位精度提高了近一倍,达到2～3m。因此,在观测环境较差的情况下建议采用渐消自适应卡尔曼滤波模式进行组合导航。