In this scanning (Figure 17) an oscillating mirror directs the laser pulse across the swath. With the use of galvanometers the pattern can be made more uniform. The data points are continuously generated in both directions of scan. The density of points is not uniform in these patterns, as points tend to come closure toward the end of swath due to deceleration of mirror. This problem is eliminated to some extent with the use of galvanometers. This is among the most common patterns and used in ALTM and Leica sensors.
Figure 17: Zig-zag or meander type pattern