Multi-channel Signal Acquisition Algorithm for Multi-beam Satellite Systems in High Dynamic Environment

The registration of point clouds in urban environments faces problems such as dynamic vehicles and pedestrians, changeable road environments, and GPS inaccuracies. The state-of-the-art methodologies have usually combined the dynamic object tracking and/or static feature extraction data into a point cloud towards the solution of these problems. However, there is the occurrence of minor initial position errors due to these methodologies. In this paper, the authors propose a fast and robust registration method that exhibits no need for the detection of any dynamic and/or static objects. This proposed methodology may be able to adapt to higher initial errors. The initial steps of this methodology involved the optimization of the object segmentation under the application of a series of constraints. Based on this algorithm, a novel multi-layer nested RANSAC algorithmic framework is proposed to iteratively update the registration results. The robustness and efficiency of this algorithm is demonstrated on several high dynamic scenes of both short and long time intervals with varying initial offsets. A LiDAR odometry experiment was performed on the KITTI data set and our extracted urban data-set with a high dynamic urban road, and the average of the horizontal position errors was compared to the distance traveled that resulted in 0.45% and 0.55% respectively.

Download Full-text

High Dynamic Spread Spectrum Signal Acquisition Algorithm based on Delay Autocorrelation

2018 International Conference on Sensor Networks and Signal Processing (SNSP) ◽

10.1109/snsp.2018.00080 ◽

2018 ◽

Author(s):

Wang Le ◽

Tang Wenzhao ◽

Hu Mi

Keyword(s):

Spread Spectrum ◽

Signal Acquisition ◽

High Dynamic

Download Full-text

Deeply Integrated GNSS/Gyro Attitude Determination System

Sensors ◽

10.3390/s20082203 ◽

2020 ◽

Vol 20 (8) ◽

pp. 2203

Author(s):

Alexander Perov ◽

Alexander Shatilov

Keyword(s):

Attitude Determination ◽

Signal To Noise Ratio ◽

Low Cost ◽

Dynamic Environment ◽

Global Navigation Satellite Systems ◽

Satellite Systems ◽

System Sensitivity ◽

Low Snr ◽

Determination System ◽

Phase Differences

Attitude determination systems based on Global Navigation Satellite Systems (GNSS) work on principle of phase interferometer, using multiple receiving antennas. They rely on a good quality of carrier phase tracking, that is not the case in real dynamic environment with low signal-to-noise ratio (SNR), for example, in a ground vehicle moving through an urban area or forest. There is still a problem in providing a GNSS attitude in such common conditions. This research is focused on improving sensitivity (i.e., the capability of providing attitude at a low SNR) and the reliability of the GNSS attitude determination system. It is contrasted with the majority of publications, where precision or computational efficiency is the main goal, but sensitivity and reliability are out of their scope. In the proposed system, sensitivity improved by using two measures: (a) tracking only phase differences instead of tracking full carrier phases—this is more sensitive due to the lower dynamics of the underlying process, and (b) using deep integration with gyroscope, where all phase differences are tracked in a vector gyro-aided loop closed on user’s attitude in state vector. The algorithm synthesis is given, and simulation results are presented in this article. This shows that the minimal working SNR is lowered from 27–36 dBHz (typical) down to 20 dBHz, even with a low-cost MEMS gyroscope.

Download Full-text

Research on INS-Aided GNSS Carrier Tracking Loop in High Dynamic Circumstance

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.464.215 ◽

2013 ◽

Vol 464 ◽

pp. 215-221

Author(s):

Xin Long Wang ◽

Chuan Jun Li ◽

Xing Cheng Li

Keyword(s):

Dynamic Environment ◽

Coupled System ◽

Tracking Performance ◽

Tracking Loop ◽

Loop Control ◽

Closed Loop Control System ◽

Loop Control System ◽

Tightly Coupled ◽

High Dynamic ◽

The Stability

GNSS receiver will produce a large Doppler shift in high dynamic environment, thus causing lock-lose of the tracking loop. INS-aided GNSS tightly coupled system can improve tracking performance in high dynamic environment by introducing the Doppler information estimated by INS. Through analyzing by the theory of closed loop control system theory and numerical simulation of the INS-aided carrier tracking loop, the results show that INS-aided carrier tracking loop can obviously improve the stability of carrier tracking performance and anti-jamming ability of the satellite navigation receiver in high dynamic circumstance.

Download Full-text