The New Literacy Studies and Time:an exploration
The New Literacy Studies and Time:an exploration
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新素养研究与时代:一次探索
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
Karin Tusting
中科院分区：
文献类型：
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作者：
Karin Tusting
单个FM/CW雷达天线和伴随的电子设备被定位在要被防护的空间内。在监视空间内的运动物体在回波返回信号中产生多普勒频移，该返回信号又被分析以获得信号内容。通过FM和距离选通，返回信号分析可针对移动目标大小和范围选择性地调整，使得低于最小大小和/或超过最大范围的移动目标不被检测为敌对对象，而最小大小或高于最小大小和/或处于最大范围或在最大范围内的移动目标被检测为敌对对象。距离选通是可选择性地调节的，以通过预定检测范围内的选定尺寸的敌对物体产生警报信号，300英尺的距离，例如一个人在一个封闭的围栏区域内的300英尺的范围内爬行通过雷达波束，而不产生没有检测范围的相对较大的非敌对物体的警报信号，例如在封闭围栏外的330英尺的范围内移动通过雷达波束的大卡车或检测范围内的相对较小的非敌对物体，例如在围栏内270英尺的范围内通过雷达波束移动的看门狗。
A single FM/CW radar antenna and accompanying electronics are positioned within a space that is to be guarded. A moving object within the space under surveillance produces a doppler frequency shift in the echo return signal which return signal is, in turn, analyzed for signal content. Through FM and range gating the return signal analysis is selectively adjustable for moving target size and range such that moving targets of below minimum size and/or beyond maximum range are not detected as hostile objects while moving targets of or above minimum size and/or at or within maximum range are detected as hostile objects. Range gating is selectively adjustable to produce an alarm signal by selected size hostile objects within a predetermined range of detection, e.g., of 300 feet, such as a man crawling through the radar beam at a range of 300 feet within an enclosed fenced-in area while not producing an alarm signal by relatively large non-hostile objects without the range of detection, such as a large truck moving through the radar beam at a range of 330 feet outside the enclosing fence or by relatively small non-hostile objects within the range of detection, such as a guard dog moving through the radar beam at a range of 270 feet inside the enclosing fence.