Kinematic orbit determination of low earth orbitsatellites using GPS and Galileo observations

Download

index.pdf

Date

2019

Author

Kılıç, Ozan

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

221
views

104
downloads

The GNSS code measurements are used to calculate the orbits of low earth orbiting satellites. Kinematic orbit determination is an approach which is based on satellite to satellite tracking of the GNSS receivers that are mounted onboard the satellites. This approach of orbit determination is independent of satellite dynamics (e.g. gravity field, air-drag etc.) and orbit characteristics (e.g. orbit height, eccentricity etc.) and kinematic precise orbit determination can be subsequently used in gravity field estimation procedures. Inclusion of Galileo measurements besides GPS observations can increase the reliability, robustness and accuracy of real-time navigation system of the spacecraft. The major aim of this thesis is to determine the orbit of a Low Earth Orbit (LEO) satellite with Kinematic Orbit Determination approach using GPS and Galileo observations. However, the observations from Galileo constellation are not fully available, since the system has not reached Full Operational Capability (FOC) yet. Hence, the corresponding observations are simulated. Real GPS data and simulated Galileo observations are used in a Kalman Filter to estimate the position and the velocity of a LEO satellite. An Adaptive Robust Extended Kalman Filter algorithm which is an extension of Kalman filter for non-linear systems is used particularly to enhance the filter performance in terms of accuracy. To obtain precise orbit of the satellite, the ionospheric effects are removed by taking ionosphere free linear combination of the dual-frequency GNSS measurements. Additionally, a Helmert variance component estimation (HVCE) is adopted for the estimation of variance components of each GNSS sensor measurement. In order to determine the accuracy of the estimated orbit, the results of Adaptive Robust Extended Kalman Filter algorithm for real LEO satellite data are compared with publicly available very precise ephemerides from Jet Propulsion Laboratory (JPL). Filter results from simulated navigation data are also compared with the true orbit generated by the simulation. Adaptive Robust Extended Kalman Filter algorithm is shown to provide an improvement of more than 70 cm in 3D RMS results for 24 hours of navigation data. In the simulation scenario, addition of simulated Galileo observations and implementation of HVCE approach led to achieve 20 cm better 3D RMS results.

Subject Keywords

Kalman filtering., GNSS, Galileo, kinematic orbit determination, Kalman filter, adaptive, robust, variance component estimation

URI

http://etd.lib.metu.edu.tr/upload/12623586/index.pdf
https://hdl.handle.net/11511/43909

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Orbit determination strategy and verification for geosynchronous satellites Köker, Abdulkadir; Tekinalp, Ozan; Department of Aerospace Engineering (2019) In this thesis, the batch and sequential orbit determination procedures for the geostationary satellites are presented. The aim of the study is to investigate the effect of the angle only and standard angle-range measurements on orbit determination accuracy. The effect of various factors on estimation accuracy such as measurement frequency, observation duration, and number of observation sites are investigated using the simulated measurement data. Estimation methods namely, nonlinear least square, extended ...
Near Real Time Orbit Detemination of BILSAT-1 Erdogan, Eren; Karslıoğlu, Mahmut Onur (2009-06-13) Reduced dynamic models combined with GPSObservations on board the satellites within an extended Kalman Filtering algorithm increases the accuracy of near real time orbit determination. Gravity model as the main force and numerical integration methods are the key concepts in the GPS based reduced dynamic orbit determination. EGM 2008 Earth Gravity Model represented by U.S. National Geospatial Intelligence Agency (NGA) EGM Development Group offers a new model for the determination of gravity accelerations. S...
Orbit Control of an Earth Orbiting Solar Sail Satellite Polat, Halis Can; Tekinalp, Ozan (2022-09-01) A concept for the utilization of solar sail satellite's propellant-free thrust capability at Low earth orbit (LEO) is proposed and its orbit control strategy is analyzed. Thrust vector control of the sail's normal direction is used to harvest the solar radiation pressure for generating the necessary acceleration to change the orbital elements. The required control vector direction is determined with two approaches. The first approach is realized by approximating the Gaussian Variational Equations at the emp...
Estimation of Deterministic and Stochastic IMU Error Parameters Unsal, Derya; Demirbaş, Kerim (2012-04-26) Inertial Measurement Units, the main component of a navigation system, are used in several systems today. IMU's main components, gyroscopes and accelerometers, can be produced at a lower cost and higher quantity. Together with the decrease in the production cost of sensors it is observed that the performances of these sensors are getting worse. In order to improve the performance of an IMU, the error compensation algorithms came into question and several algorithms have been designed. Inertial sensors conta...
Minimum fuel station keeping maneuver strategy for Turksat geostationary satellites Erdal, T; Tekinalp, Ozan; Tulunay, Yurdanur (1999-03-24) A program, METUGEO, is developed to predict the orbital parameters of a geostationary satellite. The program is verified by comparing its predictions to a similar program used at the TURKSAT ground control station. The program is employed to test and compare long term inclination (north) maneuver strategies for TURKSAT series satellites. Two strategies are investigated. The first one being the actual strategy used at the TURKSAT ground control station, and the second one is the long-term strategy proposed b...

Citation Formats

O. Kılıç, “Kinematic orbit determination of low earth orbitsatellites using GPS and Galileo observations,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Geodetic and Geographical Information Technologies., Middle East Technical University, 2019.