3)The latter, on the other hand, emits energy in order to scan objects and areas whereupon a passive sensor then detects and measures the radiation that is reflected or backscattered from the target.而后者本身散发出来能量,以便对被测物体和区域 进行扫描,这样,被动传感器就能探测和测量出由目标物反射或散发 出来的射线。 注释:主语 The latter指代 active sensors;注意 whereupon是连词, 意为“因此,于是”,引导结果状语从句; that is reflected or backscattered from the target是定语从句,修饰先行词the radiation 2021/2/20 P3 End2021/2/20 P.3 3) The latter, on the other hand,emits energy in order to scan objects and areas whereupon a passive sensor then detects and measures the radiation that is reflected or backscattered from the target. 而后者本身散发出来能量，以便对被测物体和区域 进行扫描，这样，被动传感器就能探测和测量出由目标物反射或散发 出来的射线。 注释：主语The latter 指代active sensors；注意 whereupon是连词， 意为“因此，于是”，引导结果状语从句；that is reflected or backscattered from the target是定语从句，修饰先行词the radiation. End