追蹤目標並對目標定位是在無線感測器網路中的重要應用，在這些應用中，感測器蒐集、監視並追蹤目標的移動行為。但感測器的能源通常是由有限的電池所供應，因此能源的使用效率問題是在無線感測器網路中是不可或缺的。大部分現存的目標追蹤協定需要定期地喚醒感測器以追蹤目標，也因此產生了不必要的能源消耗。在這篇論文中提出了一個具有能源效率的目標定位機制，為了要節省能源，該協定固定了追蹤目標的感測器數量，但仍然維持目標定位的品質在可接受的水準。藉由只選擇一小部分的感測器來做定位，其他沒有被選到的感測器可以直接進入睡眠狀態而不是定期地醒來追蹤目標。由模擬結果顯示了該機制不但節省了龐大的能量還延長了感測器網路的生命週期。

Target tracking and localization are important applications in wireless sensor networks. In these applications, sensor nodes collectively monitor and track the movement of a target. They have limited energy supplied by batteries, so energy efficiency is essential for sensor networks. Most existing target tracking protocols need to wake up sensors periodically to perform tracking. Some unnecessary energy waste is thus introduced. In this thesis, an energy efficient mechanism for target localization is proposed. In order to preserve energy, the protocol fixes the number of sensors for target tracking, but it retains the quality of target localization in an acceptable level. By selecting a set of sensors for target localization, the other sensors can sleep rather than periodically wake up to track the target. Simulation results show that the proposed mechanism saves a significant amount of energy and also prolongs the network lifetime.

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