由多帧欠采样影像重建高分辨率影像的方法   总被引：2，自引：1，他引：2  

钦桂勤  耿则勋等 《测绘学院学报》2002,19(1):32-35

针对同一区域多帧影像分辨率均很低的情况，首先讨论了多帧1维欠采样影像重建理论及模型，在此基础上分析了2维多帧欠采样影像的重建问题，推导出一般模型。实验结果表明，由多帧具有相异信息的欠采样影像经过完全配准后，可以生成一幅空间高分辨率的影像。  相似文献   

一种提高CCD成像卫星空间分辨率的方法研究   总被引：10，自引：0，他引：10  

周春平  田越  季统凯  吴胜利  张凤坡  许东  时春雨  姚勇航 《遥感学报》2002,6(3):179-182

从卫星硬件设计与地面软件处理相结合的角度出发，建立了一套提高卫星图像空间分辨率的方法。对模拟靶标图像、一航景物图像、遥感图像分别进行了不同分辨率成像效果的计算机模拟。结果表明，所建立的卫星图像空间分辨率提高理论是正确的，使卫星图像空间分辨率提高2倍甚至更多在理论上是可行的。这一研究成果的实际应用，将会提高卫星的空间分辨率，也可以在保持卫星分辨率的条件下，缩小光学仪器的焦距，使卫星相机小型化，减小其体积和重量。  相似文献   

重庆市区域稳定性层次分析模糊综合评价   总被引：10，自引：0，他引：10  

聂洪峰  祁生文  孙进忠  刁淑娟 《工程地质学报》2002,10(4):408-414

重庆直辖市建立后 ,其幅员面积由原来的 2 .3万km2 扩大到 8.2万km2 ,原有资源与环境数据已不能满足政府决策的需要 ,因而比较系统地分析评价区域稳定性对重庆直辖市经济发展中长期规划、重大工程选址与布局及移民搬迁 ,实现可持续发展具有十分重要的意义。本文在前人工作的基础上 ,利用层次分析两级模糊综合评判的方法对重庆直辖市全境进行了区域稳定性评价工作 ,编制了区域稳定性评价图。  相似文献   

Geopositioning Accuracy of Ikonos Imagery: Indications from Two Dimensional Transformations   总被引：1，自引：0，他引：1  

Harry B. Hanley  & Clive S. Fraser 《The Photogrammetric Record》2001,17(98):317-329

Earth observation satellites with 1m resolution, such as Space Imaging's Ikonos system, offer the photogrammetric and remote sensing communities a significant new means for geospatial information collection. These satellites possess the potential for pixel-level geopositioning precision and promise timely, highly automated generation of two dimensional (2D) and three dimensional (3D) spatial information products. This paper concentrates on the pursuit of optimal accuracy and considers an essential first step in the evaluation of the Ikonos imaging system, namely the metric integrity of the sensor system. In the absence of sensor calibration information (the camera model), an empirical evaluation approach has been adopted. This involves an assessment of 2D transformations between image and planar object space. It is shown that based on results obtained in the Melbourne Ikonos Testfield, 2D geopositioning to 0.5 m accuracy is possible from the base-level "Geo"product when a modest amount of good quality ground control is available and sub-pixel image mensuration is achieved. These findings are applicable to both near-nadir imagery and oblique stereo images. Moreover, the results obtained suggest that there are no significant geometric perturbations in the sensor system and initial image processing, which augurs well for the successful application of non-collinearity based 3D orientation and triangulation models for Ikonos imagery.  相似文献   

New analytical and numerical approaches for geopotential modeling     

M. S. Petrovskaya  A. N. Vershkov  N. K. Pavlis 《Journal of Geodesy》2001,75(12):661-672

 The standard analytical approach which is applied for constructing geopotential models OSU86 and earlier ones, is based on reducing the boundary value equation to a sphere enveloping the Earth and then solving it directly with respect to the potential coefficients _n,m . In an alternative procedure, developed by Jekeli and used for constructing the models OSU91 and EGM96, at first an ellipsoidal harmonic series is developed for the geopotential and then its coefficients _n,m ^e are transformed to the unknown _n,m . The second solution is more exact, but much more complicated. The standard procedure is modified and a new simple integral formula is derived for evaluating the potential coefficients. The efficiency of the standard and new procedures is studied numerically. In these solutions the same input data are used as for constructing high-degree parts of the EGM96 models. From two sets of _n,m (n≤360,|m|≤n), derived by the standard and new approaches, different spectral characteristics of the gravity anomaly and the geoid undulation are estimated and then compared with similar characteristics evaluated by Jekeli's approach (`etalon' solution). The new solution appears to be very close to Jekeli's, as opposed to the standard solution. The discrepancies between all the characteristics of the new and `etalon' solutions are smaller than the corresponding discrepancies between two versions of the final geopotential model EGM96, one of them (HDM190) constructed by the block-diagonal least squares (LS) adjustment and the other one (V068) by using Jekeli's approach. On the basis of the derived analytical solution a new simple mathematical model is developed to apply the LS technique for evaluating geopotential coefficients. Received: 12 December 2000 / Accepted: 21 June 2001  相似文献   

PERFORMANCE ANALYSIS OF INTEGRATED GPS/GLONASS CARRIER PHASE-BASED POSITIONING   总被引：2，自引：0，他引：2  

DAI LiwenHAN ShaoweiChris Rizos 《地球空间信息科学学报》2001,4(4):9-18

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MM5模式中不同对流参数化方案的比较试验   总被引：58，自引：2，他引：58  

王建捷  胡欣等 《应用气象学报》2001,12(1):41-53

应用MM5中尺度模式, 在60、20和10 km模式分辨率下, 分别选用4种不同对流参数化方案 (KUO方案、GRELL方案、KAIN-FRITSCH方案和BETTS-MILLER方案, 以下简称KU、GR、KF和BM方案) 对1996年8月3~4日石家庄暴雨过程进行数值模拟试验.模拟结果的对比分析及其与观测的比较表明:主要雨带位置对参数化方案并不是十分敏感, 但随分辨率提高, 雨带分布特征的模拟更接近实况; 当分辨率提高到10 km时, 虚假的降水中心也明显增加; 模拟的暴雨中心强度随分辨率的提高而增强并随参数化方案的不同有所变化, 但均比实况偏弱.分析还发现, MM5模式的GR、KF及BM方案的次网格降水对总降水的贡献率随分辨率的提高而减小, 而KU方案的情况则呈现出不合理的缓慢增加态势.虽然4种方案下模拟的水平环流特征有较好的一致性, 但模拟的云物理特征和垂直运动特征还是存在一定差别的, 这种差别对定点、定量降水和天空状况、地面气温、湿度等要素的准确预报都会产生影响.因此, 在预报和模拟中应考虑预报和研究对象的特点来选择对流参数化方案.  相似文献   

应用高分辨CT（HRCT）扫描弥补腔隙诊断之不足     

王甦  李鹏  李力  钟清君 《CT理论与应用研究》2001,10(2):21-23

目的：应用高分辨CT（HRCT）扫描方法，增加对头颅腔隙梗塞诊断的可靠性，材料和方法：对临床疑有腔隙的病人，在基底节区及可疑部位加用HRC扫描，遇到腔隙病灶与像素颗粒难以区分时在相同层面或上下1－2mm处做HRCT扫描。结果，有489例常规CT正常的病例哪现了腔隙灶，在遇到的502例不易诊断的可疑病灶中，经HRCT确诊的真正腔隙灶300例，伪腔隙（像素）202例，同时发现HRCT对正常脑组织结构的显示要较常规CT越得多，结论HRCT不仅能提高腔隙性梗塞的检出率，还能辨伪腔隙，是弥补常规CT对腔隙诊断不足的较好手段。  相似文献   

反射波法地震勘探在工程勘察中的应用   总被引：2，自引：0，他引：2  

何强  黎大虎  赖敏  何玉林 《地震研究》2001,24(3):258-261

对于地下复杂的地质构造，地震反射波法比折射波法能够提供更多更详细的地下信息。多次覆盖反射波法观测系统可以增加同一反射点的重复观测次数，从而起到压制干扰，提高有效波信号的作用。其次选取合适的地震参数能有效地拓宽有效波频带范围，对地震勘探分辨率的提高起到非常重要的作用。  相似文献   

The impact of resolution on the accuracy of hydrologic data derived from DEMs   总被引：3，自引：0，他引：3  

TANG Guo-an  HUI Yang-he  Josef Strobl  LIU Wang-qing 《地理学报(英文版)》2001,11(4):393-401

1 Introduction Automated extraction of drainage features from DEMs is an effective alternative to the tedious manual mapping from topographic maps. The derived hydrologic characteristics include stream-channel networks, delineation of catchment boundaries, catchment area, catchment length, stream-channel long profiles and stream order etc. Other important characteristics of river catchments, such as the stream-channel density, stream-channel bifurcation ratios, stream-channel order, number…  相似文献