Research On The Zenith Blind Zone And Prediction For Satellite Trace For Altitude-Azimuth Optoelectronic System

The optoelectronic measurement is one of main methods in the area of satellites measurement. At present mounts of optoelectronic measurement system have mainly two kinds of frame, i.e. altitude-azimuth form and equatorial form. The vast majority of large telescopes built are of an altitude-azimuth pedestal design in order to track fast moving satellites. However, there is a fundamental limitation to the standard altitude-azimuth optoelectronic system. That is, the occasional situation where the object of interest passes directly overhead (90 zenith pass). Azimuth axis must rotate nearly 180?instantly. Therefore, the standard two-axis altitude-azimuth pedestal will be unable to remain pointed at the object through the zenith pass event. That is the so-called problem of the zenith blind zone for the altitude-azimuth measurement system. It is very important to research on the problem of the zenith blind zone and correlative technology in theory and practice. Research also leads to some directions for future investigation.In the dissertation the development actuality of correlative tracking technology around the zenith are summarized by the numbers. Three solutions are presented, that is, tilt azimuth axis design, three-axis design, program steering. These solutions have one common requirement that measurement system must be provided with the ability of real-time predictive tracking. A pure software solution is given in order to gather more tracking data.The reason of the zenith-blind-zone forming is analyzed detailedly. The conclusion is that the extent of the zenith blind zone was restricted by three parameters: maximum azimuth angular velocity of tracking mount, flight level and airspeed of the target. In astronomical coordinates (reference mark is north latitude 43.9 ), analyzed is the effect of azimuth angular velocity, acceleration and altitude angular velocity, acceleration etc. Some formulae were given to compute all correlative quantities.With regard to the course of data processing beforehand, the thesis focuses on outliers eliminating technology because of outlier increasing acutely of high-elevation tracking (approaches 10-20%). In order to calculate the orbit of the satellite, we established satellite movement model based on celestial mechanics and spaceflight dynamics.After work above is finished, with regard to object trajectory prediction, we research on satellite orbit algorithm mainly in the dissertation. Limitation of Kalman filter is studied. Because satellite movement model is nonlinear system, we consider extended Kalman filter and adaptive filter. At last, the part of theories and arithmetic concerning optoelectronic measurement system were tested with experiments. The experiment verifies that the theoretical analysis is correct and very valuable for engineering.