Atmospheric turbulence induced synthetic aperture lidar phase error compensation

2016 ◽  
Vol 381 ◽  
pp. 214-221 ◽  
Author(s):  
Tian-an Lu ◽  
Hong-ping Li
Keyword(s):  
Atmospheric Turbulence ◽  
Error Compensation ◽  
Phase Error ◽  
Synthetic Aperture

A channel phase error compensation method for multi-channel synthetic aperture ladar

Optik ◽  
2019 ◽  
Vol 178 ◽  
pp. 830-840
Author(s):  
Shuai Wang ◽  
Maosheng Xiang ◽  
Bingnan Wang ◽  
Fubo Zhang ◽  
Yirong Wu
Keyword(s):  
Error Compensation ◽  
Phase Error ◽  
Compensation Method ◽  
Synthetic Aperture

Algorithm of Phase Error Compensation for Inverse Synthetic Aperture Ladar

2013 ◽  
Vol 50 (10) ◽  
pp. 102801
Author(s):  
阮航 Ruan Hang ◽  
吴彦鸿 Wu Yanhong ◽  
叶伟 Ye Wei ◽  
贾鑫 Jia Xin
Keyword(s):  
Error Compensation ◽  
Phase Error ◽  
Synthetic Aperture

Phase Error Compensation in Airborne Synthetic Aperture Lidar Data Processing

2015 ◽  
Vol 35 (8) ◽  
pp. 0801002
Author(s):  
鲁天安 Lu Tianan ◽  
李洪平 Li Hongping
Keyword(s):  
Data Processing ◽  
Error Compensation ◽  
Phase Error ◽  
Synthetic Aperture ◽  
Lidar Data

scholarly journals Channel Phase Error Compensation for MIMO-SAR

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Lei Zhang ◽  
Yunkai Deng ◽  
Robert Wang
Keyword(s):  
High Resolution ◽  
Error Compensation ◽  
Phase Error ◽  
Synthetic Aperture ◽  
Error Source ◽  
Processing Stage ◽  
Novel Technique ◽  
Internal Calibration ◽  
Multichannel Systems ◽  
Wide Swath

Multi-input multioutput (MIMO) is a novel technique to achieve high-resolution as well as wide swath in synthetic aperture radar (SAR) systems. Channel imbalance is inevitable in multichannel systems that it declines the imaging quality. Generally, the imbalance cannot be fully compensated by simple internal calibration in a MIMO-SAR system. In this paper, a new algorithm based on raw data is presented to remove the channel phase error. Based on the error source, this approach models the phase error as two parts: the transmit phase error and the receive phase error. The receive phase error is removed using cost function at the azimuth processing stage, whereas the transmit phase error is estimated with correlation. Point target simulations confirm the influence of channel phase error and the validation of the proposed approach. Besides, the performance is also investigated.

scholarly journals Analysis of the Subdivision Errors of Photoelectric Angle Encoders and Improvement of the Tracking Precision of a Telescope Control System

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2998 ◽  
Author(s):  
Jiawei Yu ◽  
Qiang Wang ◽  
Guozhong Zhou ◽  
Dong He ◽  
Yunxia Xia ◽  
...  
Keyword(s):  
Error Compensation ◽  
Phase Error ◽  
Tracking Error ◽  
Great Influence ◽  
Measuring Error ◽  
Distribution Law ◽  
Lissajous Figure ◽  
Amplitude Error ◽  
Noise Error ◽  
Angle Encoder

Photoelectric angle encoders, working as position sensors, have a great influence on the accuracy and stability of telescope control systems (TCS). In order to improve the tracking precision of TCS, a method based on subdivision error compensation for photoelectric angle encoders is proposed. First, a mathematical analysis of six types of subdivision errors (DC error, phase error, amplitude error, harmonic error, noise error, and quantization error) is presented, which is different from the previously used analysis based on the Lissajous figure method. In fact, we believe that a mathematical method is more efficient than the figure method for the expression of subdivision errors. Then, the distribution law and period length of each subdivision error are analyzed. Finally, an error compensation algorithm is presented. In a real TCS, the elevation jittering phenomenon occurs, which indicates that compensating for the amplitude error is necessary. A feed-forward loop is then introduced into the TCS, which is position loop- and velocity loop-closed, leading to a decrease of the tracking error by nearly 54.6%, from 2.31” to 1.05”, with a leading speed of 0.25°/s, and by 40.5%, from 3.01” to 1.79”, with a leading speed of 1°/s. This method can realize real-time compensation and improve the ability of TCS without any change of the hardware. In addition, independently of the environment and the kind of control strategy used, this method can also improve the tracking precision presumably because it compensates the measuring error inside the photoelectric angle encoder.

scholarly journals Modified Chirp Scaling Algorithm for Ultra-High Resolution Spaceborne-SAR

2021 ◽  
Vol 2083 (3) ◽  
pp. 032048
Author(s):  
Tao He ◽  
Pengbo Wang ◽  
Jixiang Ma ◽  
Xinkai Zhou ◽  
Lingling Xue
Keyword(s):  
High Resolution ◽  
Phase Error ◽  
Equation Model ◽  
Synthetic Aperture ◽  
Signal Spectrum ◽  
Integration Time ◽  
Range Cell ◽  
Range Cell Migration ◽  
Range Equation ◽  
Chirp Scaling Algorithm

Abstract The hyperbolic range equation model (HREM) and equivalent squint range model (ESRM) are applied in traditional chirp scaling algorithm (CSA). However, these range models cannot describe the satellite range history in the high-resolution case accurately because of the long azimuth integration time. The non-negligible phase error caused by this will lead the targets distort. In this paper, a modified chirp scaling algorithm (MCSA) is proposed by introducing a novel high-precision range model. A more accurate signal spectrum is calculated through it. Then, the modified chirp scaling factor, range compression filter, range cell migration correction (RCMC) filter and azimuth compression filter can be derived based on this signal spectrum, and the focused target obtained at last. Finally, the experimental results, to validate the proposed algorithm, adopted by the sliding spotlight synthetic aperture radar (SAR) simulation are provided.

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