Using the RacoonLab, simulations can be performed in the area of on-orbit service. A controlled approach to a target is part of the mission. Within the simulation environment there are different modules with different tasks and one of them is the mechanicsimulation. It is responsible for the calculation motion equations of all satellites.
It was not known how the simulation is constructed and how it performs the calculations in detail. Moreover, there was a presumption that the code was not necessary for the use mostly. For these reasons, the mechanical simulation was examined for its properties and the structure was described more accurate with this information. In addition, the implementation should be shortened and reduced to the essential. The aim of this thesis was also to extend the existing code by including various elements. Therefor an interface for the manual input of new propagators, the consideration of orbit perturbations and a working force injection was required.
The bullet algorithm library used for the computation of the equations has been removed, because of its poor utility. In addition, an undisturbed two-body simulation was detected in the Racoon mechanical simulation. For this reason, a new propagator was implemented, which also takes the gravitational perturbations caused by the earth into account. In this case, zonal perturbations can be determined explicitly up to a degree of 6. Zonal, tesseral and sectoral accelerations without limit in order and degree can be calculated by a recursive method. In addition, another propagator has been added which is using other integration methods.
After the implementation the new propagators were checked for their accuracy and compared to similar simulations from STK. First, however, it becomes apparent that changing the structures and deleting the bullet environment implies a change in the satellite position within a 10-8-meter range. The comparison of the existing propagator with a two-body simulation from STK yields position differences of up to two millimeters. The comparison of the propagator (J2/4) supplemented by zonal terms with a comparable STK-J2/4 simulation results in a deviation of the center of gravity about 70 meters on all axes. Examining the recursive algorithm of the new propagator for its deviations compared to an STK propagator, which takes the same perturbations into consideration, leads to much bigger differences. In this case, the results differ by a maximum of 900 meters.
In order to be able to evaluate the differences precisely, a comparison of the unperturbed two-body simulation with the zonal version of the new propagator was carried out. There are differences up to 100 km.
In addition, the certain algorithms were analyzed and compared with regard to their efficiency and speed. There was no essential difference detected.
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Using the RacoonLab, simulations can be performed in the area of on-orbit service. A controlled approach to a target is part of the mission. Within the simulation environment there are different modules with different tasks and one of them is the mechanicsimulation. It is responsible for the calculation motion equations of all satellites.
It was not known how the simulation is constructed and how it performs the calculations in detail. Moreover, there was a presumption that the code was not nec...
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