scholarly journals A Stellar Imaging Error Correction Method Based on an Ellipsoid Model: Taking Ziyuan 3-02 Satellite Data Analysis as an Example

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4259
Author(s):  
Bo Wang ◽  
Wei Zhou ◽  
Yuyang Gao ◽  
Qinghong Sheng

Stellar point image coordinates are one of the important observations needed for high-precision space attitude measurement with a star sensor. High-coupling imaging errors occur under dynamic imaging conditions. Using the results of preliminary star point extraction from star sensor imaging data combined with a superimposed time series, we analyze the relative motion and trajectory based on the star point image, establish an image error ellipsoid fitting model based on the elliptical orbit of a satellite platform, and achieve geometric error correction of a star sensors’ image star point using multi-parameter screening of the ambiguous solutions of intersection of the elliptic equations. The simulation data showed that the accuracy of the correction error of this method reached 89.8%, and every star point coordinate required 0.259 s to calculate, on average. In addition, it was applied to real data from the satellite Ziyuan 3-02 to carry out the correction of the star points. The experiment shows that the mean of attitude quaternion errors for all its components was reduced by 52.3%. Our results show that the estimation parameters of dynamic imaging errors can effectively compensate for the star point image observation value and improve the accuracy of attitude calculation.

2021 ◽  
Vol 263 ◽  
pp. 105817
Author(s):  
Jie Yang ◽  
Qingquan Liu ◽  
Gaoying Chen ◽  
Xuan Deng ◽  
Li Zhang

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Jean-Marie Guyader ◽  
Wyke Huizinga ◽  
Dirk H. J. Poot ◽  
Matthijs van Kranenburg ◽  
André Uitterdijk ◽  
...  

2018 ◽  
Vol 11 (9) ◽  
pp. 5167-5180 ◽  
Author(s):  
Kaisa Lakkala ◽  
Antti Arola ◽  
Julian Gröbner ◽  
Sergio Fabian León-Luis ◽  
Alberto Redondas ◽  
...  

Abstract. Non-ideal angular response of a spectroradiometer is a well-known error source of spectral UV measurements and for that reason instrument specific cosine error correction is applied. In this paper, the performance of the cosine error correction method of Brewer spectral UV measurements in use at the Finnish Meteorological Institute (FMI) is studied. Ideally, the correction depends on the actual sky radiation distribution, which can change even during one spectral scan due to rapid changes in cloudiness. The FMI method has been developed to take into account the changes in the ratio of direct to diffuse sky radiation and it derives a correction coefficient for each measured wavelength. Measurements of five Brewers were corrected for the cosine error and the results were compared to the reference travelling spectroradiometer (QASUME). Measurements were performed during the RBCC-E (Regional Brewer Calibration Center – Europe) X Campaign held at El Arenosillo, Huelva (37∘ N, 7∘ W), Spain, in 2015. In addition, results of site audits of FMI's Brewers in Sodankylä (67∘ N, 27∘ E) and Jokioinen (61∘ N, 24∘ E) during 2002–2014 were studied. The results show that the spectral cosine error correction varied between 4 and 14 %. After that the correction was applied to Brewer UV spectra the relative differences between the QASUME and the Brewer diminished even by 10 %. The study confirms that the method, originally developed for measurements at high latitudes, can be used at mid-latitudes as well. The method is applicable to other Brewers as far as the required input parameters, i.e. total ozone, aerosol information, albedo, instrument specific angular response and slit function are available.


Engineering ◽  
2012 ◽  
Vol 04 (11) ◽  
pp. 768-773 ◽  
Author(s):  
Saleh Al-Omar ◽  
Atef Obeidat

Author(s):  
Y. Kang ◽  
C. Y. Zhao ◽  
Q. Zhang ◽  
C. S. Yang

Unwrapping error is a common error in the InSAR processing, which will seriously degrade the accuracy of the monitoring results. Based on a gross error correction method, Quasi-accurate detection (QUAD), the method for unwrapping errors automatic correction is established in this paper. This method identifies and corrects the unwrapping errors by establishing a functional model between the true errors and interferograms. The basic principle and processing steps are presented. Then this method is compared with the L1-norm method with simulated data. Results show that both methods can effectively suppress the unwrapping error when the ratio of the unwrapping errors is low, and the two methods can complement each other when the ratio of the unwrapping errors is relatively high. At last the real SAR data is tested for the phase unwrapping error correction. Results show that this new method can correct the phase unwrapping errors successfully in the practical application.


Sign in / Sign up

Export Citation Format

Share Document