[Retracted] Optimal Defect Detection and Sensing System of Railway Tunnel Radar considering Multisensor System Combined with Active Interference Suppression Algorithm

Table 2

The difference between the dielectric constant of each parameter and the thickness of the test.

Dielectric constant		Volume ratio%		Concrete dielectric constant	Calculated lining thickness
Air	Water	Air	Water
1	81	5	1	6.25	0.38
1	81	4	2	6.74	0.37
1	81	3	3	7.32	0.36
1	81	2	4	7.68	0.35
1	81	1	5	8.31	0.34