Satellite Orbit Theory And Its Applications

Artificial satellite is currently the most widely used class of spacecraft in space exploration and space application. While a lot of work had been done by researchers around the world on the orbit theory of satellite, and fundamental theories had been well established for different applications, new problems arise continuously in practical applications and call for consideration. This thesis deal with some problems arising in my research work and practical applications, such as the construction of perturbing solutions of Mars low orbiters, using aerobraking to insert planetary orbiters, comparison of different earth atmosphere density models used in orbit determination and propagation and relevant issues in the use of phased array radar for space debris detection.Basic theories of satellite orbit are introduced, including the transformations between the International Terrestrial Reference System and the Geocentric Celestial Reference System based on IAU2000resolutions and the perturbation methods for artificial satellite orbit.Most of the tesseral harmonics with the third degree zonal harmonic of the Mars gravity filed are an order of magnitude larger than the corresponding terms of the Earth. Considering these differences, methods to construct the perturbing solutions of the Mars low obiters are discussed, and the importance of the coupled terms between the tesseral harmonics and the second degree zonal harmonic is analyzed. The analytical solutions of the coupled terms together with complete perturbing solutions of the Mars low orbiters for the nonspherica! potential gravity are presented, and their correctness is proved by numerical method.Issues of using aerobraking to insert planetary orbiters are investigated, including the fuel saved by using aerobraking, the time needed and the orbit control requirement in aerobraking. The relation between the time needed in aerobraking and the aerobraking parameters is studied in detail. These parameters contain the scale height of the target planet’s atmosphere, the drag coefficient, the spacecraft’s effective surface to mass ratio and the maximal allowed dynamic pressure. It shows that the aerobraking time needed has an inverse relationship with the spacecraft’s effective surface to mass ratio and the maximal allowed dynamic pressure, which can help mission design.Using the orbital ephemeris of CHAMP rapid science orbit as pseudo-observations, the effects of the solar flux and the planetary geomagnetic activity index on the earth atmosphere density are analyzed through precise orbit determination. A comparison is made between some widely used atmosphere density models by their performance in orbit determination and propagation of CHAMP satellite. It shows that, when used in orbit determination and propagation of CHAMP satellite, the more complex density models which have considered the solar flux and geomagnetic activity index do have some advantages compared to the simple exponential density model which considered neither, but there is no qualitative difference in precision. Those results obtained can help us to choose the appropriate models in different applications.Advantages of the phased array radar in space debris detection are investigated. The ill-condition in precise orbit determination using only range observations obtained by a single station is analyzed, and influences of the distributions of observations on the accuracy of precise orbit determination are studied. The results obtained can facilitate radar observation planning. A method is proposed to improve the accuracy of the semi-major axis of initial orbit elements obtained using single arc of radar observations by using multiple arcs of radar observations, which can be used to improve the convergence of precise orbit determination that is not guaranteed as the accuracy of angle measurements from phased array radar are generally poor. At last, the influences of the location of phased array radar on its observation capability are investigated.