Table 1.

Comparison of advantages and disadvantages of TLS and ALS.

	TLS	ALS
Advantages	More detailed and precise point cloud. Better control over the captured point cloud; less redundant data to filter out during the post-processing stages. TLS-based technology is less complex to operate than ALS, which incorporates GPS and IMU elements.	ALS is highly automated and requires less manual movement of the instrument. It requires less emphasis on each scan’s angle and target, as it can be maneuvered at different heights off the ground, which captures more points. More points are captured than in typical TLS scans, therefore, larger surface areas can be covered by the scans. It can capture harder-to-reach targets (e.g., roofs of buildings) and larger areas in a shorter period.
Disadvantages	TLS is highly manual and requires the movement of the scanner to capture the intended target(s). There is less flexibility in the device’s mobility; thus, incomplete or obstructed scans are common. Larger point clouds take longer amounts of time to acquire. TLS devices often are unable to reach remote or hard-to-reach locations.	Pre-planned flight paths are often required to reduce the amount of redundant point cloud data. These devices are highly dependent on weather conditions, due to consistent speeds being required for uniform point clouds. With an abundance of data captured, ALS point clouds require more complex and time-consuming post-processing methods.