A Study Of Geostationary Satellite Collocation

With the growing use of the geostationary orbit, the increasing geostationary satellite has led to congestion at hot spots in the geostationary altitude in particular. A technique known as collocation has been employed to account for the limited geostationary orbit resources. Collocation is to place more than one geostationary satellite in one geostationary orbit window (±0.1°). This technique has been studied in 1980s and applied in1990s in other country. With the repaid development of this technique, many countrys have placed more than one geostationary satellites in one geostationary orbit window. For example, ESA has placed seven ASTRA satellites at 19.2°E and HOYBIRD satellites at 13°E. Our country has placed tow satellites in one geostationary orbit window. With the development aerospace industry, more and more geostationary satellites will be used , so more satellite collocation will be need.The perturbation will change the orbital parameter of a geostationary satellite, and make it drift out of the orbit window. The perturbation and the maneuver execution errors and Orbit determination errors will make the collocation satellites Close to each other leading to collision risk. So keeping more than one satellites within the assigned control box with no collision and no satellite eclipses is the main task of study collocation. Therefore, some researches are taken out in following respects:1. Conception, current status, application advantage of Collocation, and main researching contents in Colocation.2. Analysing relative motion of the geostationary satellite with the effect of the main perturbation. Providing only the differential solar radiation pressure effects will change the relative motion of the collocation satellites.3. Analysing the constraints of collocation. On the base of investigating the viable orbital element separation methods for collocation, the paper compers each methods with relative motion effect of the orbit element deviation.4 Discussing the North South Station-Keeping (NSSK) and East West station-keeping (EWSK) strategy base on Eccentricity and Inclination Separation. The optimal control in the East West Station-Keeping manoeuveres for collocation geostationary satellite is presented. And the synchronous with asynchronous manoeuvres is compared. On the basis of this, the paper analyzes the problem using asynchronous and EIS Parallel.5. Analysing the relative motion correction of the collocation satellites from orbit element difference, derivating the relative motion correction equation using one normal maneuver and three tangential maneuvers. And combining EWSK with relative motion correction in plane is presented.6. Derivating the equation of relative motion from the collocation satellits orbit element difference. And this paper used microwave radar and angle measurement with wireless phase discrimination to measure the relative information. On the basis of this, the adaptive Kalman filter was utilized for the estimation of relative orbit.