Satellite SAR Remote Sensing of Great Lakes Ice Cover,Part 2. Ice Classification and Mapping

During the 1997 winter season, shipborne polarimetric backscatter measurements of Great Lakes (freshwater) ice types using the Jet Propulsion Laboratory C-band scatterometer, together with surface-based ice physical characterization measurements and environmental parameters, were acquired concurrently with Earth Resource Satellite 2 (ERS-2) and RADARSAT Synthetic Aperture Radar (SAR) data. This polarimetric data set, composed of over 20 variations of different ice types measured at incident angles from 0° to 60° for all polarizations, was processed to radar cross-section to establish a library of signatures (look-up table) for different ice types. The library is used in the computer classification of calibrated satellite SAR data. Computer analysis of ERS-2 and RADARSAT ScanSAR images of Great Lakes ice cover using a supervised classification technique indicates that different ice types in the ice cover can be identified and mapped, and that wind speed and direction can have an influence on the classification of water as ice based on single frequency, single polarization data. Once satellite SAR data are classified into ice types, the ice map provides important and necessary input for environmental protection and management, ice control and ice breaking operations, and ice forecasting and modeling efforts.     

Kelvin Probe measurements of polymer coated gold substrates: Mechanism studies

The origin of work-function changes induced in polymer/metal structures (polyacrylic acid (PAA), ammonium and sodium polyacrylate) upon ammonia exposure is studied. To understand and explain the mechanism systematic measurements of uncoated and polymer coated metals are performed in Kelvin Probe (KP) setups. Additional data have been acquired through gravimetric and electrochemical experiments (cyclic voltammetry (CV)). The results obtained confirm that the field effect sensitive processes are taking place at the metal/polymer interface and allow their modelling. The intrinsic sensitivity of metallic samples upon ammonia exposure is influenced by the presence of coating polymers, by their ability to sorb water and to keep the metal surface wet or dry.     

Windows98系统下的远程维护方法

指出在Windos98操作系统下远程维护的必要性,并从理论上分析了实现远程维护的可能性,最后给出实现远程维护的两种方法。     

Vehicle Teleoperation Interfaces

Despite advances in autonomy, there will always be a need for human involvement in vehicle teleoperation. In particular, tasks such as exploration, reconnaissance and surveillance will continue to require human supervision, if not guidance and direct control. Thus, it is critical that the operator interface be as efficient and as capable as possible. In this paper, we provide an overview of vehicle teleoperation and present a summary of interfaces currently in use.     

一种针对PT2262编码芯片的编码软件设计

PT2262编码芯片常用于无线遥控器中,为了避免相互干扰,一般要求在一定范围内多个发射器的地址编码不同,若对PT2262的地址码进行手工编码,则很费时且易出现重复的现象。本文通过分析基于PT2262的遥控发射器发射出的码特征,提出了一种针对PT2262编码芯片的编码软件设计。     

The Remote Product Check and Acceptance Technology Based on Web

1 Introduction The remote product check and acceptanceis ani mportant part of the e-purchase ,andthelast essential linkto a successfully e-purchase .By tri mming and opti mizing the traditional purchase process and the automation ofrepetitive work,the e-purchase systembased on Internet technology greatly raises the efficiency of bothsides ofthe business ,reduces the cost and the cycle of order form disposal as well as the items on stock of both sideswhich eventuallyleads tothe falling of the p…     

闽江口湿地遥感影像最佳景观观察尺度的选择

应用遥感和地理信息系统技术,对景观最佳观察尺度选择的方法进行了探讨;构建了“定量化景观指数粒度敏感区间,定性化尺度大小,定性与定量相结合决定最佳观察尺度值“的最佳景观观察尺度选择模式,并以ASTER遥感影像为数据源,应用该模式对闽江口湿地景观最佳观察尺度进行了研究,指出闽江口湿地的景观观察尺度应以50m和100m为主,最大尺度不应超过200m.     

遥测遥控技术及其在钢铁工业中的应用

对我国工业遥测、遥控技术及其在钢铁工业中的应用现状进行了述评。二遥技术作为信息技术的一个分支,在信息时代必将有一个大的发展,本文针对我国的现状指出了其发展方向。     

从TM影像中提取城镇建筑覆盖区专题信息的改进方法

选用TM影像作为城镇建筑覆盖区专题信息提取的数据源，在Bayes的最大似然法半自动提取城镇专题信息和建筑指数法自动提取城镇专题信息分类方法的基础上，通过二值逻辑演算，综合两种方法的分类结果，去掉不属于城镇的信息，得到真正的城镇建筑覆盖区专题信息。实验结果表明，改进后的分类方法，兼有自动与半自动的优点，其分类精度大大提高。特别是对于短期变化(如防洪区)较大、面积较大而复杂的研究区来说，这一方法的应用弥补了单一分类方法的不足。     

Optimal classification methods for mapping agricultural tillage practices

The classification of agricultural tillage systems has proven challenging in the past using traditional classification methods due to the similarity of spectral reflectance signatures of soils and senescent crop residues. In this study, five classification methods were examined to determine the most suitable classification algorithm for the identification of no-till (NT) and traditional tillage (TT) cropping methods: minimum distance (MD), Mahalanobis distance, Maximum Likelihood (ML), spectral angle mapping (SAM), and the cosine of the angle concept (CAC). A Landsat ETM+ image acquired over southern Michigan and northern Indiana was used to test these classification methods. Each classification method was validated with 293 ground truth sampling locations collected commensurate with the satellite overpass. Classification accuracy was then assessed using error matrix analysis, Kappa statistics, and tests for statistical significance. The results indicate that of the classification routines examined, the two spectral angle methods were superior to the others. The cosine of the angle concept algorithm outperformed all the other classification routines for tillage practice identification and mapping, yielding an overall accuracy of 97.2% (Kappa=0.959).