大类招生下的测绘类专业人才培养方案优化初探

实行按学科大类招生和培养促进了创新交叉型人才的培养。本文对武汉大学测绘学院大类招生下的测绘类专业人才培养方案进行了探讨,对培养测绘类专业创新人才培养有一定的参考意义。     

在线动态水利专题地图系统设计与实现

以浙江省水利专题数据为例,本文基于Vue.js框架和OpenLayers开源地图引擎,设计并实现了在线动态水利专题地图系统。该系统通过可扩展的专题制图模板提供清晰化的制图流程,通过可定制的水利专题符号库增强制图功能的个性化和制图效果,创新地将数据双向绑定和响应式视图更新机制引入专题地图的渲染,并基于底层Canvas实现了在线高清专题地图输出,对提升水利行业专题地图的定制能力和制图效率有一定的积极意义。     

一种基于贪心算法的纹理排样改进方法

针对基于贪心算法的纹理排样方法组织细小纹理块时空间利用率不高的问题,本文提出了一种基于贪心算法的纹理排样改进方法。首先,使用贪心算法对纹理块的最小外包矩形进行初排样,然后计算纹理图的有效模板,均匀划分网格,搜索无效空间的最大矩形加入待排区域,再排入纹理块,直到搜索不到可排区域为止。结果表明,本文算法有效地提高了纹理图的空间利用率,并减少了模型纹理内存。     

计算机人工智能的发展现状与未来趋势

测绘科技发展已进入一个相对关键的时期,需要从战略层面来考虑如何推动其未来发展。基于对测绘科技发展历史的系统回顾,深刻剖析了测绘科技发展的一般规律,即所处的科学范畴、应用需求、新技术发展是影响和决定测绘科技发展方向的三大关键因素。这一规律是研究确定未来测绘科技发展战略思路的基本遵循。基于此,在重点分析人工智能技术发展趋势及其对测绘科技发展已有影响的基础上,阐述了人工智能与大地测量、地理信息数据获取、地理信息数据处理与应用等技术融合发展下的未来智能化测绘科技发展趋势,提出了传统的野外测量将逐渐被无人驾驶飞机、汽车、轮船以及卫星等智能化的机器所替代的设想,以及实现这一设想需要解决的系列难题。     

河北省灵寿县西石门金矿黄铁矿热电性标型及其找矿意义

河北省灵寿县西石门石英脉型金矿位于华北地台太行隆起区之南东部的阜平矿集区,与该区石湖大型金矿受不同断裂控制。黄铁矿是矿床的主要载金矿物,以4个世代产出于黄铁矿-石英阶段(Ⅰ)、石英-黄铁矿阶段(Ⅱ)、多金属硫化物阶段(Ⅲ)和石英-碳酸盐阶段(Ⅳ)等4个成矿阶段,其中,石英-碳酸盐阶段的黄铁矿十分稀少。本矿段黄铁矿单晶热电系数变化范围为-328～341μV/℃,从早期到晚期,4个世代的黄铁矿热电系数离散性先增大再减小,石英黄铁矿阶段(Ⅱ)离散性最大。从黄铁矿-石英阶段(Ⅰ)至石英-碳酸盐阶段(Ⅳ),黄铁矿热电导型的变化规律是P>N(Ⅲ)→P>>N(Ⅳ);P型黄铁矿热电系数均值αP和出现率P%由浅部到深部,总体为逐渐降低,局部呈波状起伏,与矿石金品位呈正相关关系。黄铁矿的热电系数温标计算和投图表明,该矿床的成矿温度集中在168～330℃,为中低温矿床。热电系数在50～200μV/℃之间的黄铁矿是富金矿段的标志。综合分析认为,该矿床290m以下仍有良好的找矿潜力。     

“天绘一号”卫星测绘相机在轨几何定标

卫星在空间环境运转过程中,测绘相机的几何参数会发生不可预估的变化,从而对摄影测量定位精度和数据处理精度产生影响。因此,所有测绘卫星都对星载相机的几何参数进行在轨定标,监测相机几何参数在轨运行状态下的变化情况。本文着重介绍了\"天绘一号\"卫星在轨几何定标的内容和采用的方法。     

土地覆盖制图：基于最优化遥感数据的支撑向量机分类

遥感数据具有在不同空间、光谱和时间尺度上获取地表测量信息的能力,使其成为获取土地覆盖信息的一个主要数据源。影像分类即把卫星影像上的相关像元划分给某类已知的土地覆盖类型的过程。支撑向量机（SVMs）是一种土地覆盖分类的新技术。三种常用的SVMs是：基于线性和多项式的SVM以及具有高斯核函数的SVM分类器,分类能否成功地应用有赖于其各自选择的最佳参数。但是海量的遥感数据使得这些参数的确定速度十分缓慢。本文研究了一种新的基于最优化遥感数据压缩技术的SVM分类方法。研究显示用于获取SVM参数的数据量能够在不影响土地覆盖的分类精度的前提下进行压缩。数据压缩成功的应用于多项式和高斯核函数的SVM分类,而线性SVM的分类精度却非常低。     

Use of SPOT 5 and IKONOS imagery for mapping biocenoses in a Tunisian Coastal Lagoon (Mediterranean Sea)

Mapping marine biocenoses is an efficient method for providing useful data for the management and conservation of Mediterranean lagoons. Fused images from two satellites, SPOT 5 and IKONOS, were tested as management tools for identifying specific ecosystems in the El Bibane lagoon, situated in southern Tunisia near the Libyan border. The objectives of this study were to provide a precise map of the entire El Bibane lagoon using fused images from SPOT 5 and to compare fused images from SPOT 5 and IKONOS over a test-area. After applying a supervised classification, pixels are automatically classified in four classes: low seagrass cover, high seagrass cover, superficial mobile sediments and deep mobile sediments. The maps of the lagoon revealed and confirmed an extremely wide distribution of seagrass meadows within the lagoon (essentially Cymodocea nodosa; 19 546 ha) and a large area of mobile sediments more or less parallel to the shore (3 697 ha). A direct comparison of overall accuracy between SPOT 5 over the entire area, SPOT 5 over the test-area and IKONOS over the test-area revealed that these tools provided accurate mapping of the lagoon environment (83.25%, 85.91% and 73.41% accuracy, respectively). The SPOT 5 images provided greater overall accuracy than the IKONOS image, but did not take into account the heterogeneous spatial structure of the seagrasses and sediments present in the lagoon environment. Although IKONOS imagery provided lower overall accuracy than SPOT 5, it proved a very useful tool for the mapping of heterogeneous structures as it enabled the patchiness of formations to be better taken into account. The use of SPOT 5 and IKONOS fused images appears to be very promising for completing the mapping of lagoons in other regions and countries of the Mediterranean Sea.     

Calculation of the added mass of circular cylinders in shallow water

The added mass of hull section shapes must be known, in order to carry out any studies of ship motions, which may be associated with either seakeeping or manoeuvring. Determination of the added mass in deep water can involve conformal mapping or surface singularity distributions. However, in shallow water the problem of determining the added mass is made more difficult by the proximity of the seabed. In this paper, three approaches to the problem of finding the added mass of semi-circular sections are explored. Although there is no known exact solution to this problem, the relationships given by the three methods are compared and the approximate nature of the solutions is examined. The first method is a series solution, which is taken here to include more terms than are normally given in the existing literature. The other two solutions are considered to be new, and so are given in some mathematical detail.     

省级基础测绘1∶1万比例尺数字测绘产品的质量检验

省级基础测绘1∶1万比例尺数字测绘产品包括DEM,DOM,DLG,DRG、元数据、文档簿等。为验证数字测绘产品最终成果的精度和可靠性,可选择多种方案进行质量检验;在选择检验方案时,既要考虑检验的成本、周期,又要考虑检验方案的科学性和严密性。针对不同的数字测绘产品,该文给出了与之相适应的检验方法,并阐明了检验内容和注意事项。