目前GPS靜態定位水平精度較高程精度高，高程分量標準差平均約為水平分量的三倍。高程的理論誤差通常為數公分，使得衛星高程測量精度未能達到某些高精度應用需求。 因一次差模式中高程分量與時間分量具有高相關性，故本研究藉由求取一次差分時間偏差，得接收器時間偏差的行為模式，並嘗試率定時間偏差進而達到提升高程精度的目的。 由於一次差分載波相位觀測量中相位模稜與時間參數具有絕對相關之特性，故本研究利用二次差轉一次差模式與電碼求取初始時間偏差等方式解決相位模稜之問題。模稜求定後，使用附加約制條件式之最小二乘法求得時間參數偏差值，並利用數筆已解算時間偏差的時刻，進行下一時刻時間偏差量的預估，預估模式使用二次多項式，並進一步分析時間偏差對幾何定位的影響。 At present, the GPS static positioning accuracy of horizontal is better then vertical. Average, vertical standard bias is 3 times for horizontal standard bias. GPS survey can’t application in vertical positioning occasions of height accuracy cause of theory error of vertical general have several centimeters upward. Height correlation between vertical parameter and time bias parameter in single difference. The behaviors of the relative positioning caused by the receiver clock bias as well as the effect from receiver clock bias in single difference model are described. For absolute correlation between ambiguity parameter and time bias parameter of carrier phase in single difference. Therefore to use several method to deal this problem like application of double difference ambiguity and use pseudorange to calculate time bias initial value. After ambiguity fixed, to use least square method calculate time bias in single difference. And through already calculate time bias of several epochs to estimate next epoch time bias. To goto a step further to analysis time bias for effect of positioning bias. In study, estimate mode performs by quadratic function.
