An object is approximately 300 m away. Find the approximate time difference to calculate the distance using a light pulse reflected from the object.
This ranging method can be employed for measuring shorter distances limited by time measurement capability and detecting the reflected signal for longer distances. Surveying instruments for measured by an eletronic computeing system that records the changing reflected-pluse travel time and computes velocity. These and the interferometric methods such as those used in Doppler radar are beyond the scope of this text.