摘要： 为了追踪和记录空间移动对象的运动轨迹，需要记录其在各个采样时刻的空间坐标数据。但是对于采样时刻之间的对象坐标以及上一采样时刻结束，下一采样时刻到来之前的坐标数据的确定仅仅是一种估计，这种估计本身存在一定的非确定性。该文提出了针对时空数据非确定性的时空最近点查询即NN 查询（Nearest Neighbor query）的算法NNU（Nearest Neighbor query with Uncertainty），并介绍了其在二维无约束空间运动中的应用。

关键词: 时空数据；非确定性查询；最近点

Abstract: In order to track the trajectory of moving objects in space, it is required to store the locations at the updating times. After an update, the location of the object is unknown until the next update is conducted. Under this condition, the data of the moving objects is only an estimate of the actual locations at most points of time. This inherent uncertainty affects the accuracy of the answer to queries. This paper introduces a method of nearest neighbor query under uncertainty environment and introduces its application to the query of moving objects of two dimensional unconstrained moving environments

Key words: Spatial-temporal data; Uncertainty query; Nearest neighbor