Postprocessing Synchronization of a Laser Scanning System Aboard a UAV

Author(s)

Machado, Marcela do Valle ^[1] ; Garcia Tommaselli, Antonio Maria ^[1] ; Torres, Fernanda Magri ^{[1, 2]} ; Campos, Mariana Batista ^[1]

Affiliation

^[1] Sao Paulo State Univ, Sch Technol & Sci, Dept Cartog, UNESP, Sao Paulo - Brazil

^[2] Brazilian Inst Geog & Stat IBGE, Geodesy & Cartog Div GGC, Goiania, Go - Brazil

• Document type: Journal article
• Source: PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING; v. 85, n. 10, p. 753-763, OCT 2019.
• Web of Science Citations: 0

Abstract

Synchronization of airborne laser scanning devices is a critical process that directly affects data accuracy. This process can be more challenging with low-cost airborne laser scanning (ALS) systems because some device connections from off-the-shelf sensors are less stable. An alternative to synchronization is performing a postprocessing clock correction. This article presents a technique for postprocessing synchronization (off-line) that estimates clock differences based on the correlation between the signals from the global navigation satellite system (GNSS) trajectory and the light detection and ranging (lidar) range, followed by refinement with a least-squares method. The correlation between signals was automatically estimated considering the planned flight maneuvers, in a flat terrain, to produce altimetric trajectory variations. Experiments were performed with an Ibeo LUX laser unit integrated with a No-vAtel SPAN-IGM-S1 inertial navigation system that was transported by an unmanned aerial vehicle (UAV). The planimetric and altimetric accuracies of the point cloud obtained with the proposed postprocessing synchronization technique were 28 cm and 10 cm, respectively, at a flight height of 35 m. (AU)

• FAPESP's process: 13/50426-4 - Unmanned airborne vehicle-based 4D remote sensing for mapping Rain Forest biodiversity and its change in Brazil (UAV_4D_Bio)
• Grantee: Antonio Maria Garcia Tommaselli
• Support Opportunities: Regular Research Grants