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Strip Adjustment and Registration
Published in Jie Shan, Charles K. Toth, Topographic Laser Ranging and Scanning, 2017
The sensor parameters and configuration jointly define the performance potential of any LiDAR system, and the objective is to approach it as closely as possible under normal operational conditions. The laser sensing unit is generally characterized by its ranging and scanning accuracy. Modern systems support extremely good ranging accuracy, typically 1–2 cm (1σ), up to relatively high flying heights (1000 m AGL). As the moving parts in the laser sensor have shrunk over time, and these smaller components can be better controlled, this has resulted in faster and more even mirror motion, for example. In addition, the encoding performance has improved and, thus, the mirror position can be calibrated to a high accuracy.
Development Toward Autonomous Systems
Published in Ulrich Rembold, Robot Technology and Applications, 2020
To get a three-dimensional image of the environment, range data must be combined with two-dimensional images. The main techniques for ranging are triangulation and time-of-flight measurements. There are two different types of triangulation: active and passive. Passive triangulation involves merging two images taken from stationary devices to produce stereo images. The difficulty with passive triangulation is the correspondence problem. Active triangulation uses a stationary camera and a moving light source. The scene is scanned by a moving spot or strip of light. The reflected image points are detected, and their displacement is used to calculate range.
Force-System Resultants and Equilibrium
Published in Richard C. Dorf, The Engineering Handbook, 2018
Light detection and ranging (LIDAR or lidar), perhaps the most significant innovation to date, is similar in many respects to radio detection and ranging (radar). Lidar can be used to measure characteristics of a remote target, including distance, speed, rotation, and chemical composition and concentration. Known initially as optical radar or laser radar, lidar can be thought of as a radar system that uses electromagnetic radiation at higher, optical frequencies - most commonly a laser.
Evaluation and correction of smartphone-based fine time range measurements
Published in International Journal of Image and Data Fusion, 2021
Yuntian Brian Bai, Allison Kealy, Lucas Holden
Ranging in an indoor environment can be complicated, especially in a dense multipath environment. Factors such as different propagation media, multipath, clock errors and changes in the surrounding environment (e.g. moving people) can all affect ranging accuracy. Therefore, several issues need to be solved to address the offset deviation problems, which include: Definition of the surrounding environment type (only LOS condition is considered).Whether the offset deviation is a constant value across a number of same-model routers within the same manufacturer.Comparison of the different offset deviation errors from different types of APs.Evaluation of the offset deviation and see whether the errors are consistent or vary alongside the change of the distance between an AP and an end-user device.
Performance analysis of parameter estimator on non-linear iterative methods for ultra-wideband positioning
Published in International Journal of Image and Data Fusion, 2023
Chuanyang Wang, Bing He, Liangliang Shi, Weiduo Huang, Liuxu Shan
We evaluate the UWB sensor network positioning system based on a DW1000 module. It is a single chip wireless transceiver based on a UWB technique compliant with the IEEE802.15.4–2011 standard. It allows high data rate communications, up to 6.8 Mb/s, and it is a perfect fit in wireless sensor network applications (Decawave 2016). As shown in Figure 1, the ranging measurements in these transceivers are performed based on a two-way ranging (TWR) method by determining the time of flight (TOF) of signals travelling between an anchor and a tag (Decawave 2015).
A Robust Unscented Kalman Filter applied to Ultra-wideband Positioning
Published in International Journal of Image and Data Fusion, 2020
Chuanyang Wang, Yipeng Ning, Xin Li, Haobo Li
Figure 15 represents the UWB sensor network positioning system based on the DecaWave Mini2016 suite, including the anchor and tag nodes. By determining the time of flight (TOF) of signals travelling between the anchor and tag, the ranging measurements in these transceivers is performed based on the two way ranging (TWR).