Exploiting Attitude Sensing in Vision-Based Navigation for an Airship

Table 4

Comparison of visual odometry before and after loop-closing, with the GPS as reference. All values are given in meters.

Unit: meters	3D position error			2D position error			Error in the length of t
	Avg.	Max.	Final	Avg.	Max.	Final	RMS	Avg.	Max.
Visual odometry: Procrustes only	16.5	43.6	43.6	15.3	43.3	43.3	0.73	−0.46	0.59
Visual odometry: after loop-closing	13.5	25.2	5.8	11.7	23.5	5.2	1.08	−0.57	1.1