Figure 6

Examples of loop closure experiments using visual SIFT features. a Example locations used to examine the loop closure detection performance. b Multiple matched features from a loop closure in area a in (a). A 180° difference in course is easily handled by the SIFT features. c Location b has both a 180° course difference and a translative change but a couple of features are still matched. d 2 correct and 2 false matches in area c makes it unsuitable for loop closure updates.