Abstract: Sunshine has played a critical role in trajectory analysis. It is of great significance to design an algorithm that could not only estimate the sunshine information of the trajectory effectively， but also remove the redundant points and keep the necessary sunshine-based information. This paper proposes a sunshine based trajectory simplification algorithm， which considers the urban trajectory character， to solve the challenges of trajectory analyzing in various sunshine related scenarios. On the one hand， an orientation model is established to abstract the relationship between trajectory and sunlight. On the other hand， a sunshine related trajectory simplification model is proposed， and the genetic algorithm is applied to find the points that need to be reserved. Finally， the real-world data of Minneapolis， US， is used for experiment. The results demonstrate that the proposed algorithm can effectively reduce the number of turning points in the trajectories under the control of bound T_max.

Key words: intelligent transportation, trajectory simplification, solar power, genetic algorithm;spatio-temporal data