The end point of the baseline is usually set with a permanent measurement mark to indicate its point. Such a point is called a baseline point. For example, the length baseline verification field is a field site used to calibrate electromagnetic waves and laser rangefinders. After a certain period of use of the rangefinder and other instruments, their internal parts will age and decay, which will seriously affect the accuracy of the distance measurement. The baseline verification is compared with the true length to find the correction number and find the instrument’s problems. Ensure the accuracy of measurement.