Least squares orbit estimation including atmospheric density uncertainty consideration

2019 ◽  
Vol 63 (12) ◽  
pp. 3916-3935 ◽  
Author(s):  
Fabian Schiemenz ◽  
Jens Utzmann ◽  
Hakan Kayal
1958 ◽  
Vol 12 (64) ◽  
pp. 307
Author(s):  
C. B. T. ◽  
M. Lotkin ◽  
C. Berndtson

Indian Regional Navigation Satellite System (IRNSS) is India’s own navigation system. It is a seven satellite constellation with the operational name NavIC – Navigation with Indian Constellation. Satellite Orbit determination (OD) estimates the position and velocity of orbiting satellite. The two main estimation algorithms widely used in Global Navigation Satellite Systems (GNSS) are Extended Kalman Filter (EKF) and Least Squares. This study on Batch Least Squares (BLS) - Differential Correction (DC) algorithm demonstrates precise orbit estimation of any GEO missions using only range measurements with crude initial state parameters. Currently, the study is based on simulated inputs and the satellite orbits are successfully estimated with position error in sub-centimeters level. Further, the work will be extended to live data of IRNSS satellites.


2020 ◽  
Vol 92 (7) ◽  
pp. 993-1000 ◽  
Author(s):  
Houzhe Zhang ◽  
Defeng Gu ◽  
Xiaojun Duan ◽  
Kai Shao ◽  
Chunbo Wei

Purpose The purpose of this paper is to focus on the performance of three typical nonlinear least-squares estimation algorithms in atmospheric density model calibration. Design/methodology/approach The error of Jacchia-Roberts atmospheric density model is expressed as an objective function about temperature parameters. The estimation of parameter corrections is a typical nonlinear least-squares problem. Three algorithms for nonlinear least-squares problems, Gauss–Newton (G-N), damped Gauss–Newton (damped G-N) and Levenberg–Marquardt (L-M) algorithms, are adopted to estimate temperature parameter corrections of Jacchia-Roberts for model calibration. Findings The results show that G-N algorithm is not convergent at some sampling points. The main reason is the nonlinear relationship between Jacchia-Roberts and its temperature parameters. Damped G-N and L-M algorithms are both convergent at all sampling points. G-N, damped G-N and L-M algorithms reduce the root mean square error of Jacchia-Roberts from 20.4% to 9.3%, 9.4% and 9.4%, respectively. The average iterations of G-N, damped G-N and L-M algorithms are 3.0, 2.8 and 2.9, respectively. Practical implications This study is expected to provide a guidance for the selection of nonlinear least-squares estimation methods in atmospheric density model calibration. Originality/value The study analyses the performance of three typical nonlinear least-squares estimation methods in the calibration of atmospheric density model. The non-convergent phenomenon of G-N algorithm is discovered and explained. Damped G-N and L-M algorithms are more suitable for the nonlinear least-squares problems in model calibration than G-N algorithm and the first two algorithms have slightly fewer iterations.


Methodology ◽  
2015 ◽  
Vol 11 (3) ◽  
pp. 110-115 ◽  
Author(s):  
Rand R. Wilcox ◽  
Jinxia Ma

Abstract. The paper compares methods that allow both within group and between group heteroscedasticity when performing all pairwise comparisons of the least squares lines associated with J independent groups. The methods are based on simple extension of results derived by Johansen (1980) and Welch (1938) in conjunction with the HC3 and HC4 estimators. The probability of one or more Type I errors is controlled using the improvement on the Bonferroni method derived by Hochberg (1988) . Results are illustrated using data from the Well Elderly 2 study, which motivated this paper.


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