visual sighting meaning in English

目视瞄准

With its minimized structure , the path provides an optimal light - amplifying ratio ; ( iii ) the position sensitive detector ( psd ) is just located in front of the visual sight of operator , this makes the observation and operation more easily
该系统设计有特殊的光路，结构简洁，体积小，通过多次反射提高反射臂的光程，保证了最佳的光杠杆放大比；同时，检测系统中的位置敏感元件( psd )光敏面位于正对视线的方向，易于afm系统的操作和观察。
It is hard to track blue whale , the ocean ' s largest creature , which has almost been killed off by commercial whaling and is now listed as an endangered species . attaching radio devices to it is difficult , and visual sightings are too unreliable to give real insight into its behavior
追踪蓝鲸是相当苦难的,她是海洋中最大的生物,由于商业捕鲸几乎所有的鲸鱼被杀光而成为现在名单中一个将要绝种的物种.对鲸鱼系上无线电装置是很困难的,而眼前所看到的太不可靠而无法对鲸鱼生活状态给于真实的了解