An Iterative Doppler Velocity Log Error Calibration Algorithm Based on Newton Optimization

Table 1

Initialization	Set , , , and a coarse
Calibration process	Step 1	Substitute into (8) to calculate
	Step 2	Substitute and into (9) to construct the observation equation of
	Step 3	Establish the loss function according to (12)
	Step 4	Substitute into loss function , and calculate its gradient value
	Step 5	Determine the search direction
	Step 6	Calculate the best step and the approximate matrix , respectively, with (20) and (22)
	Step 7	Iterate the latest quaternion of attitude misalignment with (27)
	Step 8	, and loop step 1–5 until