Table 3.

Influence of processing options on shear velocity measurements.

Frequency	Method	Component
45 Hz		APxRL	RLxHF	HFxAP
	Curl + DF	2.3 ± 0.3	2.2 ± 0.3	2.3 ± 0.2
	No DF	2.7 ± 0.3	2.8 ± 0.5	2.3 ± 0.2
		HF (phase)	AP (freq)	RL (slice)
	No Curl	2.6 ± 0.2	3.2 ± 0.3	2.5 ± 0.4
76 Hz		APxRL	RLxHF	HFxAP
	Curl + DF	3.2 ± 0.4	3.1 ± 0.3	3 ± 0.3
	No DF	4 ± 0.5	3.8 ± 0.6	3.2 ± 0.2
		HF (phase)	AP (freq)	RL (slice)
	No Curl	3.4 ± 0.3	4.3 ± 0.4	3.2 ± 0.4

Velocities are reported as mean ± standard deviation, in m/s. The method we chose (Curl + DF) provided consistent measurements for all components. Disabling the directional filter (No DF) had no significant influence of the velocities measured from the HFxAP component. Disabling the curl operator (No Curl) resulted in increased velocity measurements, especially for displacement in the AP direction.