عنوان پایان‌نامه
تخمین مدار یک ماهواره با استفاده از فیلتر کالمن خنثی (UKF)
- رشته تحصیلی
- مهندسی هوا فضا -مهندسی فضایی
- مقطع تحصیلی
- کارشناسی ارشد
- محل دفاع
- کتابخانه مرکزی -تالار اطلاع رسانی شماره ثبت: 70752
- تاریخ دفاع
- ۲۹ شهریور ۱۳۹۴
- دانشجو
- سیدامیررضا روغن گیر
- استاد راهنما
- بهرام تارویردی زاده, محمد علی امیری آتشگاه
- چکیده
- تخمین مدار ماهواره با در نظر گرفتن اثرات ناهمگونی زمین و انتخاب GPS به عنوان مشاهده گر فیلتر
- Abstract
- Abstract: To implementation of a successful space mission, moving the vehicle in specific and determined trajectory is necessary. This trajectory which is called ‘orbit’ for a satellite, is estimated and compared with designed orbit. The process of orbit estimation and determination is one of the most important steps during a satellite lifetime. It is clear that by increasing the accuracy of orbit estimation, the mission success will be guaranteed. In this thesis, we have tried to determine the orbit by using Unscented Kalman Filter (UKF), in which, a GNSS is used as the observation sensor. During this goal, firstly we have simulated the satellite orbit considering oblateness effect. Secondly, exploiting a nonlinear model of orbit dynamics, preliminary orbit determination is prepared by using UKF algorithm. Here we incorporated the range between GPS satellite and space vehicle as the parameter of observation in the filter. Then the estimated preliminary output data is corrected and more precise position of the satellite is determined. At the end, the estimated orbit is compared with the simulated one, and the position and velocity errors is extracted. It is important to declare that in this research, we have exploited a semi-experimental model to predict GPS position errors in the loop of estimator. As a result, the outcomes of the research exhibits the superiority of this nonlinear approach from other linear or linearized ones. Keywords: Orbit Determination, Global Positioning System, Kalman Filter, Unscented Kalman Filter, GPS error estimation
