The precise estimation of geodetic parameters using single- and double-differenced SLR observations is investigated. While the differencing of observables is a standard approach for the GNSS processing, double differences of simultaneous SLR observations are practically impossible to obtain due to the SLR basic principle of observing one satellite at a time. Despite this, the availability of co-located SLR telescopes and the use of the alternative concept of quasi-simultaneity allow the forming of SLR differences under certain assumptions, thus enabling the use of these processing strategies. These differences are in principle almost free of both, satellite- and station-specific error sources, and are shown to be a valuable tool to obtain relative coordinates and range biases, and to validate local ties. Tested with the two co-located SLR telescopes at the Geodetic Observatory Wettzell (Germany) using SLR observations to GLONASS and LAGEOS, the developed differencing approach shows that it is possible to obtain single- and double-difference residuals at the millimetre level, and that it is possible to estimate parameters, such as range biases at the stations and the local baseline vector with a precision at the millimetre level and an accuracy comparable to traditional terrestrial survey methods. The presented SLR differences constitute a valuable alternative for the monitoring of the local baselines and the estimation of geodetic parameters.

研究了使用单差和双差 SLR 观测对大地测量参数的精确估计。虽然观测值的差分是 GNSS 处理的标准方法，但由于 SLR 一次观测一颗卫星的基本原理，实际上不可能获得同时 SLR 观测的双差分。尽管如此，同地单反望远镜的可用性和准同时性的替代概念的使用允许在某些假设下形成 SLR 差异，从而能够使用这些处理策略。这些差异原则上几乎没有卫星和台站特定的误差源，并且被证明是获得相对坐标和范围偏差以及验证当地联系的宝贵工具。在大地观测站 Wettzell（德国）使用 SLR 观测 GLONASS 和 LAGEOS 对两台位于同一地点的 SLR 望远镜进行了测试，开发的差分方法表明，可以获得毫米级的单差分和双差分残差，并且可以估计参数，例如台站的距离偏差和当地基线矢量，精度达到毫米级，精度可与传统的地面测量方法相媲美。