GPS為一發展成熟的定位與導航系統，此系統除了可提供精確的定位，亦可利用其訊號的解析度及其全球涵蓋性，將其應用於遙測，如此一來，只需接收器，不需額外的發射源，可節省不少成本。使用GPS做遙測時，透過直射、反射訊號能量分佈間之關係，可推得地理環境之狀態。本論文探討GPS反射訊號模型與環境參數之關係，另外，由於反射訊號能量分佈無法由一般接收器取得，所以將修改、設計接收器的韌體部分，以偵測反射訊號及取得相關運算值隨著時間的分佈，最後對於所做實驗結果做詳細討論，並提出建議。

　　GPS is a proven positioning and navigation system. In addition to providing accurate positioning and timing service, the GPS can be used in remote sensing due to its good resolution and superior coverage. Indeed, the omnipresence of GPS signals can serve as sources in bistatic remote sensing, leading to a cost-effective design. By observing the power distribution of direct GPS signal and reflective GPS signal, attributes of the environment can be extracted. The thesis investigates the relation of the scattering of GPS signal model to the environmental parameters. Properties of GPS signal reflection are reviewed. Moreover, the firmware of GPS receiver is upgraded to detect the reflective signal and monitor the power variation. An experiment is conducted to verify the firmware modification and remote sensing concept. Finally, preliminary results and lesson learned are provided.

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