![]() ![]() One possible solution is to maintain radio beacons in the lunar base and redeploy them before each landing mission. If radio beacons are stationary, meaning that they will be exposed to a harsh environment for a long time, the onboard electronic equipment will be fatally damaged. Without the protection of the atmosphere, the diurnal temperature variation on the Moon is more than 300 ☌. In fact, most ground beacons can only be located either by orbiters or by the deep space network on the order of hundreds of meters. With the existence of these infrastructures, the natural consequence is to make use of more ground sources to enhance the current onboard navigation capability for lunar landing missions using, for instance, radio beacons.Īll studies listed above were based on a strong assumption that uncertainties only existed in the sensor measurements, which means that all beacons were stationary and their locations were precisely pre-determined. A robotic lunar base followed by a human base will likely be constructed during these missions, which will be the first potential implementation of co-located pinpoint landing. Among all these celestial bodies, a growing number of exploration missions will land on the Moon in the future, as it is the most suitable outpost for deep space exploration. To date, many manned and unmanned landers have successfully landed on moons (Apollo and Chang’E), planets (Curiosity and Opportunity) and asteroids (Rosetta and Hayabusa-2), with landing footprints in the scale of kilometers. Safe and soft pinpoint landing (within 100 m at 3 σ from the target site ) on an extraterrestrial body has been a central objective since the beginning of human space exploration missions. Thus, this method is a potential candidate for future lunar exploration activities. The simulation results indicated that the proposed method effectively reduced the error in the position estimations caused by uncertain beacon locations and made an effective trade-off between the estimation accuracy and the computational efficiency. Then, an adaptive iterated sparse extended hybrid filter (AISEHF) was devised by modifying the prediction and update stage of SEIF with a hybrid-form propagation and a damping iteration algorithm, respectively. This scheme was designed based on the sparse extended information filter (SEIF) to locate the lander and update the beacon configuration at the same time. In this paper, we propose a radio beacon/inertial measurement unit (IMU)/altimeter localization scheme that is sufficiently robust regarding uncertain initial beacon locations. None of the available studies regarding integrating beacon measurements for pinpoint landing have considered uncertain initial beacon locations, which are quite common in practice. As a growing number of exploration missions have successfully landed on the Moon in recent decades, ground infrastructures, such as radio beacons, have attracted a great deal of attention in the design of navigation systems. ![]()
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