An empirical InSAR-optical fusion approach to mapping vegetation canopy height

Exploiting synergies afforded by a host of recently available national-scale data sets derived from interferometric synthetic aperture radar (InSAR) and passive optical remote sensing, this paper describes the development of a novel empirical approach for the provision of regional- to continental-scale estimates of vegetation canopy height. Supported by data from the 2000 Shuttle Radar Topography Mission (SRTM), the National Elevation Dataset (NED), the LANDFIRE project, and the National Land Cover Database (NLCD) 2001, this paper describes a data fusion and modeling strategy for developing the first-ever high-resolution map of canopy height for the conterminous U.S. The approach was tested as part of a prototype study spanning some 62,000 km² in central Utah (NLCD mapping zone 16). A mapping strategy based on object-oriented image analysis and tree-based regression techniques is employed. Empirical model development is driven by a database of height metrics obtained from an extensive field plot network administered by the USDA Forest Service-Forest Inventory and Analysis (FIA) program. Based on data from 508 FIA field plots, an average absolute height error of 2.1 m (r = 0.88) was achieved for the prototype mapping zone.     

Characteristics of Schottky Barrier Junction Based on Hexagonal Microtube ZnO

Hexagonal microtube ZnO was firstly grown on single crystal p-Si (111) substrates by hydrothermal method, and fabricated Ag/n-ZnO and Au/n-ZnO Schottky junction. Schottky effective barrier heights were calculated by I-V measurement. It is confirmed that the presence of a large amount of surface states related possibly to lattice imperfections existed near the surface leads to the pinning of the surface Fermi level at 0.35 eV below the conduction-band edge. Then the fabricated Schottky barrier junctions are evaluated for their use as UV photodetectors.     

基于Windows CE的线路巡检系统

首先讨论了现有线路巡检模式的不足，然后提出了利用windows CE来构建线路巡检系统。分析了该系统的硬件平台之后，提出了线路巡检系统的体系结构，阐述了该系统应具有的软件功能。在实际应用中表明，该系统在线路巡检中有较强的推广价值。     

一种新的无线电高度表原位检测的高度模拟方法

针对目前对高度表进行原位检测的需求,设计了一种新的高度模拟方法;该方法的实现以ARM为核心,通过高度模拟电路产生各种需要的高度电压信号,从而达到高度模拟的目的,并且无需对机载高度表进行拆装,操作简单、快捷、可靠性较高;实验结果表明,这种方法的高度模拟精度较高,具有一定的实用价值和经济效益.     

移动位置的信息服务系统研究

随着移动通信技术的发展,无线网的覆盖面越来越广,移动电话发起的紧急呼叫数量在全部紧急呼叫中所占的比例也随之上升。现有的无线网能为移动电话紧急呼叫提供的辅助决策信息非常少。研究的目标是设计一种精确安全的报警系统,使得市民可以便捷并安全地将案情报告给指挥中心,而且指挥中心能够根据案发地点找出最近的警力及时赶往现场,第一时间处理案情。研究表明,系统能够实现报警电话快速定位的功能,并通过地图或文字描述等方式展示位置信息,达到接警、处警对位置信息的要求。     

浅谈GPS导航系统在油田运输管理中的应用

我油田地处华北东部,随着油田不断发展,对外承包业务愈来愈多。道路营运车辆也日益增多,营运范围也逐渐扩大,给道路运输经营管理与车辆合理调度工作提出了新的要求,而全球卫星定位系统的发展为道路运输管理的有效指挥、协调控制和管理提供了技术支持。本文结合GPS系统的原理,探讨GPS系统在油田运输管理中的应用。     

Feedrate optimization and tool profile modification for the high-efficiency ball-end milling process

Trend in die/mold machining is to produce highly quailed surface using the high-speed hard machining with the ball-end cutter. The ball-end milling is, however, less efficiency than the flat end milling. It is important to optimize the feedrate that gives the maximum material removal rate constrained by an allowable surface roughness. The state-of-art of the CBN ball-end cutter technology allows increasing the tooth feed for high-speed and high-efficiency machining. However, because the spherical shape of the cutter can result in the scallop-liked cusps on the machined surface, the surface roughness consideration makes a feedrate limitation to the CBN cutter. In this paper, the optimization of the feedrate by considering the generated-scallop effect of the ball-end cutter has been studied. It was found that the tooth feed must be kept within one third of the path pick in order to keep the feed-interval scallop height not over the path-interval scallop height. Therefore, the potential capability of the CBN cutter for the larger tooth feed (i.e. high efficient) machining can not be fully exploited. It was found a notch-cut on the center of the ball-end cutter reduced the feed-interval cusp height, thus allowing an increased feedrate of more than 50% compared with the standard ball-end cutter. If the parameters of the notch-cut profile can be optimized, it is believed that the feedrate can be further increased.     

火花点燃式发动机压缩比与数字计数器读数的校正关系

采用压缩比与数字计数器的对应检索校正关系来评定检查火花点燃式发动机的机械状况。根据沿海不同地区室内室间实验室的对比与协调试验计算分析，所采用的检索法达到美国沃克夏机器制造厂规定的ASTM精度。本文提出的检索法具有快速、简捷和准确等特点，可适用于沿海地区火花点燃式发动机的机械设备状况校准试验。