scholarly journals Accurate and Autonomous Star Acquisition Method for Star Sensor under Complex Conditions

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Hao Zhang ◽  
Yanxiong Niu ◽  
Jiazhen Lu ◽  
He Zhang
Keyword(s):  
Frequency Domain ◽  
Laboratory Experiments ◽  
High Accuracy ◽  
Nonlinear Filter ◽  
Attitude Measurement ◽  
Star Sensor ◽  
Excellent Performance ◽  
Star Image ◽  
Image Simulations ◽  
Acquisition Method

Star sensor is a preferred attitude measurement device for its extremely high accuracy. Star acquisition is the essential and critical procedure, which is aiming at acquiring accurate star areas. However, degenerated acquisition results under complex conditions become one of the major restrictions for modern star sensor. In this paper, an accurate and autonomous star acquisition method is proposed. Mathematical morphology and variable thresholding are combined for accurate star extraction; motion PSF is estimated in frequency domain and nonlinear filter is adopted for star restoration. Accurate star acquisition can be achieved based on only one star image. Simulations and laboratory experiments are conducted for verification. Several existing methods are also reproduced for comparison. Acquisition results demonstrate that the proposed method is effective and an excellent performance can be achieved autonomously under complex conditions, along with more detected stars and improved acquisition accuracy.

scholarly journals Star Image Prediction and Restoration under Dynamic Conditions

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1890 ◽  
Author(s):  
Liu ◽  
Chen ◽  
Liu ◽  
Shi
Keyword(s):  
Attitude Control ◽  
Attitude Determination ◽  
Back Propagation ◽  
Prediction Method ◽  
Back Propagation Neural Network ◽  
Attitude Measurement ◽  
Star Sensor ◽  
Dynamic Conditions ◽  
Star Image ◽  
Image Prediction

The star sensor is widely used in attitude control systems of spacecraft for attitude measurement. However, under high dynamic conditions, frame loss and smearing of the star image may appear and result in decreased accuracy or even failure of the star centroid extraction and attitude determination. To improve the performance of the star sensor under dynamic conditions, a gyroscope-assisted star image prediction method and an improved Richardson-Lucy (RL) algorithm based on the ensemble back-propagation neural network (EBPNN) are proposed. First, for the frame loss problem of the star sensor, considering the distortion of the star sensor lens, a prediction model of the star spot position is obtained by the angular rates of the gyroscope. Second, to restore the smearing star image, the point spread function (PSF) is calculated by the angular velocity of the gyroscope. Then, we use the EBPNN to predict the number of iterations required by the RL algorithm to complete the star image deblurring. Finally, simulation experiments are performed to verify the effectiveness and real-time of the proposed algorithm.

High accuracy star image locating and imaging calibration for star sensor technology

2010 ◽  
Author(s):  
Shaodi Zhang ◽  
Zhijun Zhang ◽  
Honghai Sun ◽  
Yanjie Wang
Keyword(s):  
High Accuracy ◽  
Sensor Technology ◽  
Star Sensor ◽  
Star Image

High-Accuracy Star Sensor Centroid Algorithm Based on Star Image Resampling

2019 ◽  
Vol 39 (7) ◽  
pp. 0712003
Author(s):  
曹阳 Yang Cao ◽  
李保权 Baoquan Li ◽  
李海涛 Haitao Li ◽  
桑鹏 Peng Sang
Keyword(s):  
High Accuracy ◽  
Star Sensor ◽  
Star Image ◽  
Centroid Algorithm

IDENTIFICATION OF INTERHARMONICS BASED ON WAVELET PACKET TRANSFORM

2021 ◽  
Vol 3 (1) ◽  
pp. 031-036
Author(s):  
S. A. GOROVOY ◽  
◽  
V. I. SKOROKHODOV ◽  
D. I. PLOTNIKOV ◽  
◽  
...  
Keyword(s):  
Fourier Transform ◽  
Simulation Model ◽  
Frequency Domain ◽  
Time Domain ◽  
Wavelet Packet ◽  
High Accuracy ◽  
Wavelet Packet Transform ◽  
Mathematical Apparatus ◽  
Nonlinear Load ◽  
The Time Domain

This paper deals with the analysis of interharmonics, which are due to the presence of a nonlinear load. The tool for the analysis was a mathematical apparatus - wavelet packet transform. Which has a number of advantages over the traditional Fourier transform. A simulation model was developed in Simulink to simulate a non-stationary non-sinusoidal mode. The use of the wavelet packet transform will allow to determine the mode parameters with high accuracy from the obtained wavelet coefficients. It also makes it possible to obtain information, both in the frequency domain of the signal and in the time domain.

Calibration of installation angle for high accuracy shipboard star sensor

2016 ◽  
Vol 24 (3) ◽  
pp. 609-615
Author(s):  
郭敬明 GUO Jing-ming ◽  
赵金宇 ZHAO Jin-yu ◽  
何昕 HE Xin ◽  
刘冰 LIU Bing ◽  
张同双 ZHANG Tong-shuang ◽  
...  
Keyword(s):  
High Accuracy ◽  
Star Sensor ◽  
Installation Angle

High-Accuracy Waveguide Leaky-Mode Analysis Using a Multidomain Pseudospectral Frequency-Domain Method Incorporated With Stretched Coordinate PML

2013 ◽  
Vol 31 (14) ◽  
pp. 2347-2360 ◽  
Author(s):  
Chih-Yu Wang ◽  
Hsuan-Hao Liu ◽  
Shih-Yung Chung ◽  
Chun-Hao Teng ◽  
Chung-Ping Chen ◽  
...  
Keyword(s):  
Frequency Domain ◽  
High Accuracy ◽  
Leaky Mode ◽  
Mode Analysis ◽  
Frequency Domain Method ◽  
Domain Method
Sign in / Sign up

Export Citation Format

Share Document