LARES-2 is a new geodetic satellite designed for high-accuracy satellite laser ranging. The orbit altitude of LARES-2 is similar to that of LAGEOS-1, whereas the inclination angle of 70° complements the LAGEOS-1 inclination of 110°; hence, both satellites form the butterfly configuration for the verification of the Lense–Thirring effect. Although the major objective of LARES-2 is testing general relativity, LARES-2 substantially contributes to geodesy in terms of the realization of terrestrial reference frames, recovery of the geocenter motion, pole coordinates, length-of-day, and low-degree gravity field coefficients. We analyze the first 1.5 years of LARES-2 data and test different empirical orbit models for LARES-2 with and without co-estimating low-degree gravity field coefficients to find the best combination strategy with LAGEOS satellites. We found that LARES-2 orbit determination is more accurate than that of LAGEOS-1/2 due to a different satellite construction consisting of a solid sphere with no inner structure. Neither the correction for D₀ nor the empirical once-per-revolution along-track accelerations S_C/S_S have to be estimated for LARES-2 when co-estimating gravity field coefficients. The only empirical parameter needed for LARES-2 is the constant along-track acceleration S₀ to compensate for the Yarkovsky–Schach effect. On the contrary, for LAGEOS-1/2, the non-gravitational perturbations affect C₃₀ and Z geocenter estimates when once-per-revolution parameters are not estimated. LARES-2 does not face this issue. LARES-2 improves the formal errors of the Z geocenter component by up to 59% and C₂₀ by up to 40% compared to the combined LAGEOS-1/2 solutions and provides C₃₀ estimates unaffected by thermal orbit modeling issues.

LARES-2 是一颗新型大地测量卫星，专为高精度卫星激光测距而设计。LARES-2 的轨道高度与 LAGEOS-1 相似，而 70° 的倾角与 LAGEOS-1 的 110° 倾角相辅相成;因此，两颗卫星都形成了用于验证 Lense-Thirring 效应的蝶形构型。尽管 LARES-2 的主要目标是测试广义相对论，但 LARES-2 在实现地球参考系、恢复地心运动、极坐标、日长和低度重力场系数方面对大地测量做出了重大贡献。我们分析了 LARES-2 的前 1.5 年数据，并测试了 LARES-2 的不同经验轨道模型，有和没有共同估计低度重力场系数，以找到与 LAGEOS 卫星的最佳组合策略。我们发现 LARES-2 的轨道确定比 LAGEOS-1/2 更准确，因为它的卫星结构不同，由没有内部结构的固体球体组成。在共同估计重力场系数时，对于 LARES-2，既不必估计 D₀ 的校正，也不必估计每转一次沿轨道加速度 S_C/S_S。LARES-2 唯一需要的经验参数是恒定的沿轨道加速度 S₀，以补偿 Yarkovsky-Schach 效应。相反，对于 LAGEOS-1/2，当没有估计每转一次的参数时，非引力扰动会影响 C₃₀ 和 Z 地心估计。LARES-2 不会遇到此问题。 与组合的 LAGEOS-1/2 解决方案相比，LARES-2 将 Z 地心分量的形式误差提高了 59%，将 C₂₀ 的形误差提高了 40%，并提供了不受热轨道建模问题影响的 C₃₀ 估计。