Doctoral candidates and students develop a so called RACOON-Lab as a Hardware in the Loop laboratory at the Chair of Astronautics of the Technical University in Munich. The scenario of capturing or maintaining inoperative Satellites shall be simulated. To create depth images, we want to test sensors under lightning conditions in space, which are as realistic as possible. On the one hand, the sun radiation plays a very significant part. On the other hand, the influence of the earth albedo radiance in space shall be considered in the simulation as well. Therefore, we develop an earth albedo simulator to integrate it into the RACOON-Lab. The thesis will be undertaken by a method of Systems Engineering.
To recreate the lightning conditions of the reflected radiance in space, a detailed analysis on the spectral distribution of the earth albedo needs to be executed. It is obvious, that, besides the spectral distribution, also the total intensity of the earth albedo is extremely depending on several factors. This thesis concentrates on the three most important and most influential factors. These are the reflecting surface, the orbit of the relevant satellite and the Solar Zenith Angle (SZA). We work out spectral distributions, depending on the factors mentioned above, as reference spectrums, we want to recreate with respect to the solar simulator. Within this process, studies are performed to evaluate the best fitting and financially possible combination of lamp and colour filters. To validate my selection, spectral measurements of the lamp radiation need to be performed. A ballast with ignitor operates the lamp while the ballast is controlled via Arduino Teensy 3.2 including a microcontroller. The spectral measurements, realised at the Max Planck Institute of Quantum Optics (MPQ), show, that it is possible to adjust the percentual amount of the total intensity of the earth albedo simulator (with respect to the solar simulator) between 25,5 % and 67,2 %. Besides that, the measurement curves proceed very similar to the curves of the reference spectrums. Although, with this earth albedo simulator you cannot recreate the typical absorption areas.
After the successful execution of the spectral measurements, we integrate the earth albedo simulator into the RACOON-Lab with an interface to the intended “sled”. From a control room you can operate the earth albedo simulator via a wireless connection. The most important function of the simulator is the fact that you can dim the lamp with the ballast. Therefore, the spectrum of the lamp can be adjusted to the reflecting conditions in space.
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Doctoral candidates and students develop a so called RACOON-Lab as a Hardware in the Loop laboratory at the Chair of Astronautics of the Technical University in Munich. The scenario of capturing or maintaining inoperative Satellites shall be simulated. To create depth images, we want to test sensors under lightning conditions in space, which are as realistic as possible. On the one hand, the sun radiation plays a very significant part. On the other hand, the influence of the earth albedo radianc...
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