Study of a Space-Time Monitoring of High-Speed Railway Underline Structure Using Distributed Optical Vibration Sensing Technology

Table 4

Optical fiber rings and sampling points.

Start of the sampling point	End of the sampling point	Ring number	Sampling distance (m)
100	120	1	10
140	160	2	10
180	210	3	10
230	250	Middle of the fiber under test	10
260	300	4	10
320	340	5	10
350	380	6	10
380	400	End of the fiber under test	10