LiDAR Products - Sources of Error

This article seeks to concisely answer the question - what impacts on the accuracy of LiDAR derived products? The extract is from a paper presented at the recent International LiDAR Mapping Forum in the USA.

“The overall error budget of an airborne LiDAR system has been the subject of numerous publications. As shown in the diagram below, several potential error sources exist:

1. Errors related to the LiDAR instrument itself, which includes the laser rangefinder and scanner subsystems, and errors caused by the finite size of the laser footprint on the ground;

2. Errors determined by the Position and Orientation System (POS), which is required for geo-positioning data collection and processing;

3. Errors in POS/LiDAR interrelations - since the LiDAR data (range and angle measurements) are blended with the POS data, the errors associated with POS/ LiDAR interrelations can play a significant role in the error budget;

4. Errors introduced during data handling and processing, including interpolation and filtering errors, various human errors, etc. During data handling and processing the overall error budget may be reduced if advanced calibration and
optimization or “smoothing” algorithms are applied to the data set.

In order to minimize the overall error budget and optimize the design of an integrated instrument, a thorough analysis of the contribution from all error sources is required. Theoretical modeling usually helps to identify the major contributors to the error budget, and to quantify the impact of the various error sources on the final data accuracy.”

Subset of the Optech paper by Ussyshkin et al, 2008.

This is the first in a series of short extracts about the errors and expected accuracies associated with LiDAR products. Future issues will examine vertical and horizontal accuracies and related topics.