海洋二号D卫星（HY-2D）是我国第4颗海洋动力环境卫星，为研究HY-2D 卫星的DORIS的定轨精度，本文构建了卫星姿态模型，选择2021年6月5日至17日间DORIS相位测量数据，采用观测值历元间差分和动力学方法进行精密定轨。对定轨结果通过观测值拟合残差、重叠弧段、轨道互比和激光检核4种手段评估轨道精度，并讨论使用姿态模型和姿态数据两种定轨结果之间差异。结果表明：（1）13天观测值残差拟合RMS均值约为0.355mm/s，轨道重叠弧段三维差异的RMS小于2.0cm；（2）与CNES的精密轨道相比，使用姿态数据两者在R、T、N方向上差异的RMS分别为1.02cm、2.92cm和3.11cm，使用姿态模型两者在R、T、N方向上差异的RMS分别为0.97cm、2.77cm和3.15cm。两种结果接近，表明卫星姿态模型与实测姿态数据符合程度高。（3）用激光检核本文计算的轨道与CNES参考轨道的精度，测距残差的RMS分别为2.38cm和2.24cm，两种轨道精度相当。

Objective：Haiyang 2D satellite (HY-2D) is the fourth Marine dynamic environment satellite in China, which belongs to the Marine remote sensing satellite series in China, with high-precision orbit measurement, orbit determination capabilities and all-weather, all-day, global detection capabilities. The main mission of the satellite is to monitor and investigate the Marine environment, obtain a variety of Marine dynamic environmental parameters, including sea surface wind field, wave height and sea surface height, directly provide measured data for the early warning and prediction of catastrophic sea conditions, and provide support services for Marine disaster prevention and reduction, Marine rights and interests protection, Marine resources development, Marine environmental protection, Marine scientific research and national defense construction. After the launch of HY-2D satellite, HY-2B satellite and HY-2C satellite realize the three-star network observation. Accurate orbit of HY-2D is a prerequisite for mission accomplishment. It was equipped with the DORIS receiver for POD (precise orbit determination). The attitude of the satellite alternates between fixed mode and nominal yaw-steering mode. Method：In order to study the accuracy of orbit determination of HY-2D using DORIS, we build a satellite attitude model, and DORIS phase measurement data from June 5 to June 13, 2021, is selected, and the Epoch-Difference method and dynamic orbit determination method is adopted for precise orbit determination. Result：The orbital accuracy was then evaluated by post-fit residuals, overlapping, comparing with CNES and SLR. The differences between the two orbit determination results using attitude model and attitude data were discussed. The results show that:(1) Mean of the Post-fit residuals is 0.355mm/s, mean of 3D RMS is within 2cm. (2) Compare with the precise orbit by CNES, the RMS when using attitude data in the R, T and N directions are 1.02cm, 2.92cm and 3.11cm, respectively, and the RMS when using attitude model in the R, T and N directions are 0.97cm, 2.77cm and 3.15cm, respectively. The similarity between the two results indicates that the constructed satellite attitude model is in good agreement with the measured attitude data. (3) The mean RMS of SLR residuals for CNES orbit and our orbit are 2.38cm and 2.24cm respectively, indicating that the two orbits have similar accuracy. Conclusion：Our research shows that the on-board DORIS receiver have good and stable performance, by using the received data, we can provide a centimeter-level HY-2D satellite orbit, which can ensure the stable operation of satellite altimetry.