ESTIMATING SPACECRAFT ATTITUDE BASED ON IN-ORBIT SENSOR MEASUREMENTS

摘要

In this paper it has been shown, that even though the different attitude sensors used onboard a satellite has been characterised under laboratory conditions, this doesn't necessarily hold once the sensors are in orbit and working within the satellite. Especially it was found for the magnetometer and sun sensors, that their performance were much worse in orbit than during ground testing. One major contributing factor, which has not been verified yet is, that the sensors during ground testing were kept static, whereas the satellite was slowly rotating while the measurements for the in-orbit analysis were taken. Likewise, as the AAUSAT3 satellite doesn't have any absolute external reference sensors, such as e.g. a camera, the only way to determine the satellites ADS capabilities is through simulations, which has been done and it was found that the added in-orbit noise makes the estimate quite a bit worse.