Table 1.

Parameters of selected DFOS measurement methods.

Parameter	Feature	TW-COTDR	PSP-BOTDR	PPP-BOTDA	BOTDA	BOTDR	OBR (OFDR)
Strain accuracy, µε		0.1	6	10	20	50	1 *
Spatial resolution, cm	max	2	10	2	100	100	<1
	typical	10	20	10	100	200	1
Distance range, km	max	25	25	25	25	25	0.07
	typical	6	6	6	6	6	0.03

* Accuracy as provided by interrogator technical specifications.