Autonomous orbit determination (AOD) is the ability of navigation satellites to estimate with accurate satellite orbit parameters using onboard using inter-satellite link (ISL) measurements. To overcome the unobservability of the constellation rotation error in AOD when using only the ISL measurements, the properties that the orbit inclination \( i \) and the longitude of the ascending node \( \varOmega \) of the medium earth orbit (MEO) navigation satellites, which can be predicted with high accuracy over a long time, are explored. This leads to an onboard extended Kalman filter (EKF) where \( \left( {i,\varOmega } \right) \) are subjected to constraints. Three experiments are carried out to assess the effectiveness of the proposed AOD EKF and analyze the causes of the constellation rotation error by processing 30-day ISL measurements of 18 MEO satellites of BDS-3 in a distributed mode. The results verify that the proposed EKF with \( \left( {i,\varOmega } \right) \) constraints can resolve the unobservable constellation rotation error issue effectively. When using precise EOP parameters, the 3D orbit errors of BDS-3 AOD in 30 days could be less than 2.30 m. The errors increase to 3.4 m when the predicted EOP parameters are used.

中文翻译：

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基于卫星间链路测量的北斗BDS-3卫星分布式自主轨道确定的初步结果

自主轨道确定（AOD）是导航卫星使用卫星间链路（ISL）测量值在船上使用准确的卫星轨道参数进行估算的能力。为了克服仅使用ISL测量时AOD中星座旋转误差的不可观察性，中地球轨道（MEO）的轨道倾角\（i \）和上升节点的经度\（\ varOmega \）的属性探索了可以长期准确预测的导航卫星。这将导致板载扩展卡尔曼滤波器（EKF），其中\（\ left（{i，\ varOmega} \ right）\）受到约束。进行了三个实验，以评估所提出的AOD EKF的有效性，并通过在分布式模式下处理BDS-3的18个MEO卫星的30天ISL测量来分析星座旋转误差的原因。结果证明，提出的具有\（\ left（{i，\ varOmega} \ right）\）约束的EKF可以有效地解决不可观测的星座旋转误差问题。当使用精确的EOP参数时，BDS-3 AOD在30天内的3D轨道误差可能小于2.30 m。使用预测的EOP参数时，误差增加到3.4 m。