A wireless sensor network (WSN) is mainly designed to detect events' features with the required information accuracy under all kinds of physical resource constraints. Thus, theoretical model on the information accuracy is valuable in designing efficient protocols for WSNs. A definition is firstly given to quantify the information accuracy in WSNs, and then exploited the spatial correlation among sensed data from multiple jointly sensing nodes to illustrate how information accuracy varies with the number of jointly sensing nodes (M). Both the analytical and simulation results show that the information accuracy will not increase as M increases constantly. The increment of information accuracy reaches zero when M is large enough. Hence, such intuitive opinion as M always has positive effects on the degree of information accuracy will not maintain when M becomes large. The proposed model on information accuracy and energy consumption can be utilized in achieving maximum information accuracy with minimum energy consumption through estimating a proper M.%无线传感器网络的主要目标是在各种资源受限的情况下取得用户所需的信息精确度.因此,有关信息精确度的理论模型对设计无线传感器网络中有效的协议很有价值.首先提出一种无线传感器网络中信息精确度定义,然后利用节点采样数据间的空间相关性得出信息精确度随采样节点个数(M)变化的关系模型.理论分析和仿真试验结果都表明:信息精确度并非随M的增大而持续增大,当M增大到一定程度后,信息精确度的增量将趋于零,从而纠正了增大M可以持续提高信息精确度的观点.理论模型可以用来确定一个合适的M以实现用最小的能耗代价取得尽可能精确的数据.
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