sight device meaning in English

瞄准设备
瞄准装置

Because bad weather ? thick fog , mainly ? can severely curtail the reach of these line - of - sight devices , each optical transceiver node , or link head , can be set up to communicate with several nearby nodes in a network arrangement
因为坏天气（主要是浓雾）会大幅缩短这些视线设备的传输距离，因此每个光收发节点（或称连结端）的设立地点，必须可以和网路配置里的多个邻近节点进行沟通。
The sighting device of seeing optical system has two kinds of situations which are the main image and the secondary image , the main image which is the indispensable sign of presenting the target but the secondary image is not useful to the target
摘要视准式光学系统瞄准具的成像有主像和副像两种情形，主像是对目标瞄准的必要标志，副像则对目标的瞄准产生不良影响，为消除或减弱光学系统所成的副像对瞄准精度的影响，主要分析了光学系统中中心反射镜的反射和有无平行差时产生副像的原因。