The complementary nature of triangulation and ladar technologies

Abstract

3D ranging and imaging technology is generally divided into time-based (ladar) and position-based (triangulation) approaches. Traditionally ladar has been applied to long range, low precision applications and triangulation has been used for short range, high precision applications. Measurement speed and precision of both technologies have improved such that ladars are viable at shorter ranges and triangulation is viable at longer ranges. These improvements have produced an overlap of technologies for short to mid-range applications. This paper investigates the two sets of technologies to demonstrate their complementary nature particularly with respect to space and terrestrial applications such as vehicle inspection, navigation, collision avoidance, and rendezvous & docking.

STS-128 on-orbit demonstration of the TriDAR targetless rendezvous and docking sensor

“…single set of scanning optics). This configuration takes advantage of the complementary nature of these two ranging technologies to provide 3D data at both short and long range without compromising on performance [6]. The laser triangulation subsystem is largely based on the Laser Camera System (LCS) used to inspect the Space Shuttle's thermal protection system after each launch [7].…”

Robust vision-based pose estimation of moving objects for Automated Rendezvous & Docking

“…All vision systems, however, F. Aghili provide discrete and noisy pose data at relatively low rate, which is typically 1 Hz. It is worth mentioning that another 3D sensor system called TriDAR is an emerging technology that combines the complementary nature of LCS triangulation and Lidar time-of-flight for enhancing the scan range [4]. Taking advantage of the simple dynamics of a free-floating object, which is not acted upon by any external force or moment, researchers have employed different observers to track and predict the motion of a target satellite [5].…”

Geometrical Model of Laser Triangulation System Based on Synchronized Scanners

“…C. Samson et al [23] studied the accuracy of the synchronized scanning triangulation system and the error caused by the deviation of system parameters, such as mirror angle, are obtained. English Chad et al [24] designed a laser triangulation system based on synchronized scanners with lidar, which makes full use of advantages of triangulation and ladar technologies. Triangulation can be highly precise at close range, while pulsed ladar technology is capable of very long range measurements.…”