基于Kalman滤波的InSAR基线估计方法

针对目前SAR干涉测量中基线估计现存的问题,提出了利用Kalman滤波和配准参数进行基线估计的方法.所提出的方法具有不需地面控制点、不受地形限制和不依赖于轨道参数等优点,并可以估计时变的基线参数.利用南京地区的ERS-1/2 tandem数据进行了试验研究,并对提出的方法进行了验证.结果表明,在精确的卫星轨道数据和地面控制点不能获取时,所提出的方法仍能有效地估计InSAR基线.这在一定程度上补偿了轨道偏移带来的误差,为获取高精度的DEM奠定了基础.     

利用C_SURF配准的空基视频运动目标检测

目的 针对传统的车辆检测算法的性能易受低空移动平台影响造成相机自运动以及外界的干扰等问题,提出了一种基于改进的C_SURF彩色特征稳像和光流法向量相结合的方法来解决低空视频中的运动车辆检测问题。通过图像稳像消除了相机的自运动和外界干扰问题,提高了运动车辆的检测性能。实验结果显示,该方法不仅在检测车辆方面可以获得更好的检测性能,在复杂的背景环境下也能有效地检测运动车辆。     

Reduced-Dimensional Processing for Ground Moving Target Detection in Distributed Space-Based Radar

With multisatellite radar systems, several additional features are achieved: multistatic observation, interferometry, ground moving target indication (GMTI). In this letter, a new reduced-dimensional method based on joint pixels sum-difference (Sigma-Delta) data for clutter rejection and GMTI is proposed. The reduced-dimensional joint pixels Sigma-Delta data are obtained by the orthogonal projection of the joint pixels data of different synthetic aperture radar (SAR) images generated by a multisatellite radar system. In the sense of statistic expectation, the joint pixels Sigma-Delta data contain the common and different information among SAR images. Then, the objective of clutter cancellation and GMTI can be achieved by adaptive processing. Simulation results demonstrate the effectiveness and robustness of the proposed method even with clutter fluctuation and image coregistration errors     

IPTA方法在地面沉降监测中的应用

干涉点目标分析(IPTA)技术是一种新兴的In SAR形变测量技术。它克服了常规雷达差分干涉测量(DIn SAR)受失相干因素和大气延迟影响较大的问题。介绍了IPTA方法及处理流程,并对参数迭代估计、基线精化等关键问题进行了阐述。对加利福尼亚州安大略市的39幅ENVISAT ASAR数据进行IPTA处理,提取了2005—2010年间的地面沉降信息并进行了形变分析。结果表明,该方法在大范围地面沉降监测中应用效果良好。     

Using a Grid-Based Filter to Solve InSAR Phase Unwrapping

This letter presents a phase-unwrapping (PU) algorithm for synthetic aperture radar interferometry based on a grid-based filter. The proposed PU algorithm, which is based on state-space techniques, simultaneously performs noise filtering and PU. The formulation of this technique provides independence from noise statistics and is not constrained by the nonlinearity of the problem. Results obtained with synthetic data show a significant improvement with respect to other conventional PU algorithms in some situations.     

基于无线通信和视频监控技术的移动目标监控GIS系统设计

视频监控是解决因人员无法到达现场而采用设备将现场信息及时传回以供人们进行决策指挥的一种有效手段。从总体架构、技术路线、功能实现等方面阐述利用无线通信和远程视频监控技术实现移动目标监控的建设思路。该研究成果在安保、应急处置等工作中具有一定的应用前景。     

GPS基线网数据处理系统的设计与实现

本系统基于Windows98操作系统，采用面向对象的程度设计语言，具有良好的人机界面，使用方便，可直接处理多种基线处理软件的基线文件。系统的平差程序采用压缩存储技术，在现有微机内存条件下，一次处理成千上万个控制点。系统采用了图像技术，在图上可以选取基线进行检核，选取独立基线进行平差，平差后显示控制网图和误差椭圆图，图上还可以是询各种平差成果。     

ISAR Imaging of a Ship Target Using Product High-Order Matched-Phase Transform

Inverse synthetic aperture radar (ISAR) imaging of a ship target is very important compared with the plane target, and the imaging condition of the ship target is more complicated than that of the plane target due to the complexity of the ship's movement. In this letter, the received signal of a ship target is modeled as a multicomponent cubic phase signal, and the product high-order matched-phase transform is proposed to estimate the parameters of each component. Then, the instantaneous ISAR images can be obtained. Results of real data demonstrate the effectiveness of the new method proposed.     

利用遥感技术监测船舶航速的方法研究

主要讨论了两种利用遥感技术提取水面运动船舶的航速方法：利用波高谱信息提取航速和利用船尾迹中的横波信息提取航速。作者介绍了这两种方法的原理，描述了利用遥感技术提取船舶航速的工作流程，并利用模拟和实测的船尾迹波高数据对这两种方法进行了验证。从计算结果看，两种方法精度都能满足仅要求航速量级的需求者，利用波高谱信息的方法误差（10％左右）小于利用横波信息的方法误差（20％左右）。该项研究为实时或近实时探测运动船舶航速提供了新的方法。     

Optimum Polarizations for Discrimination of a Foliage-Camouflaged Target, Using Genetic Algorithms

Many realizations of foliage around a hard target are run to obtain the statistical variations of foliage and target responses. This is accomplished by using a hybrid target-foliage model, developed for the investigation of the scattering behavior of metallic targets embedded inside a forest canopy. This model is based on the coherent scattering theory of wave propagation through the foliage and an iterative physical optics approximation of scattering from the target. The model is capable of accounting for the first-order near-field interactions between the hard target and the foliage. Fully polarimetric simulation results of a foliage-camouflaged metallic target having complex geometry are generated at 2 GHz, and a polarization synthesis optimization method for improving signal-to-clutter ratio is carried out by applying genetic algorithms.     

单目智能视觉监视应用中小运动目标的检测

提出了以Cauchy分布作为图像像素比值的统计分布模型,并融合图像局部线性相关技术实现背景建模。该方法同时利用了像素点的统计特性和邻近像素点所蕴涵的丰富空间区域信息。实验表明,本文提出的算法可以抗背景中全局或局部光照的渐变和突变,有效地抑制背景中活动物体和阴影的杂波干扰。     

地面坐标作为带权观测值的空间后方交会与验后权估计

本文讨论了验后方差估计在单象空间后方交会中的应用。此时所要估计的是地面坐标和象片坐标的权。如果地面坐标有相同的方差,譬如人工标志点,则我们可将地面点视为固定点而不必作为带权观测值,且不需要进行验后方差估计。但是,若地面坐标的方差不等,譬如采用自然点(需要辨认和转剌)的情况,则必须将它们作为带权观测值逐点进行方差估计。采用这种方法可以提高平差结果的精度。     

An Improvement on the Clustering of High-Resolution Satellite Images Using a Hybrid Algorithm

The challenge of obtaining training data for supervised classifications of satellite images has led researchers to unsupervised algorithms, i.e. cluster analysis. Numerous researches have been conducted to improve quality and decrease uncertainty of results of this analysis. This study proposes a hybrid cost function as well as a hybrid clustering algorithm-Artificial Bee Colony optimization approach for the clustering of high-resolution satellite images. In order to evaluate viability of the proposed methodology, it is compared to some other classic clustering algorithms such as modified K-Means, K-Medoids, Fuzzy C-Means, and Kernel-based Fuzzy C-Means methods over three different study areas selected from a WorldView-2 satellite image. The Shannon entropy technique, Kappa coefficient, compactness, and separation criteria are used as quality and uncertainty indicators for the evaluation. The results of the study show that, compared to other methods, the hybrid algorithm obtained from the proposed cost function, Kernel-based Fuzzy C-Means method, and ABC algorithm provide clustering capabilities of higher quality and lower uncertainty levels.     

利用掩星和地基GPS研究日食电离层效应

21世纪最长的一次日全食于2009-07-22发生,从亚洲东部一直延伸到太平洋地区,同时,日食后期开始伴随着一次中等强度的磁暴。本文利用COSMIC掩星GPS数据反演了食甚时刻电子密度变化情况,利用武汉CORS地基GPS数据反演了局部TEC时序变化情况,并分析了日食电离层效应的物理机制。     

Using a Cold Earth Surface Target to Characterize Long-Term Stability of the MODIS Thermal Emissive Bands

The Moderate Resolution Imaging Spectroradiometer (MODIS) has successfully provided Earth image products for instruments on the Terra and Aqua satellites since 2000 and 2002, respectively. Maintaining accurate radiometric calibration and calibration consistency between two sensors is an important issue for continued quality of long-term data records, especially as the instruments operate beyond their original projected mission lifetime. A strategy to use frequent MODIS measurements of the brightness temperature of the land surface in the area surrounding Dome Concordia, Antarctica (75.1, 123.4 ) to track the long-term stability of MODIS Band 31 is presented. Dome Concordia, located on the Antarctic plateau, is one of the most homogeneous land surfaces on Earth in terms of surface temperature and emissivity, with a seasonal temperature range of 190-250 K. The extremely dry, cold, and rarefied atmosphere of the site makes it ideal to track and detect any long-term changes in the MODIS thermal band response through trend analyses of near-nadir MODIS overpass data in conjunction with surface temperature measurements. Application of this approach shows an average relative bias between Terra and Aqua MODIS Band 31 (11 ) measurements of 0.08 K, which is well within the calibration uncertainty.     

基于稀少控制点的SPOT5卫星立体条带影像的生产应用研究

随着相关技术的发展,高分辨率卫星遥感影像在测绘产品生产中的应用越来越广泛和深入。本文主要通过西部无图区测图的应用实践,讨论利用有理多项式方法、基于稀少控制点纠正的SPOT5HRS立体条带影像的测图生产情况,并对DLG、DEM等产品进行精度检测;同时与传统的航摄方法进行对比,分析其生产效率等情况。     

一种基于非专用接收机的GPS实时定姿算法

描述一种基于非专用接收机的GPS实时定姿算法,主要工作可以分为两个部分:第一,采用最小二乘方法和乔里斯基分解,基于基线长度约束压缩整周模糊度搜索空间,以达到实时计算的目的;第二,结合姿态角约束,使用金字塔算法提高了整周模糊度求解效率.经过实验,算法在基线长度为3 m的条件下,航向角精度优于0.1°.     

Adobe Flex框架中的视频GIS系统设计与开发

根据Web服务概念,在AdobeFlex框架中,聚合地理信息服务、视频流媒体服务和XML文档服务,开发了富互联网应用(RIA)模式的视频GIS。系统开发实验表明,基于Flex框架中的网络视频GIS设计和开发简单快速,系统界面美观高效,有广阔的应用潜力。     

激光导线系统测定拱坝位移

根据生产实际的需要,本文提出一种激光导线系统,可用它来测定拱坝或其它曲线型建筑物的位移。本文对该系统的原理,转角棱镜的设计原则,棱镜安置误差对测定转析角变化量的精度影响,以及该系统的观测方法,拱坝位移量的计算等作了详细的论述。     

Using parallel projection mathematics to orient an object relative to a single image

The paper presents a straightforward method of calculating approximate orientation parameters (six degrees of freedom) of a known targeted object relative to a single calibrated camera. These can then initialise an optimised non-linear calculation of the same parameter values. The method uses the mathematics of a scaled parallel projection and is particularly suited to narrow angle images obtained using a telescope, telephoto or zoom lens. However, the method can also be used with cameras having wider fields of view provided the target group occupies a moderately small part of the image.