The JPL Planetary and Lunar Ephemerides DE440 and DE441

The planetary and lunar ephemerides called DE440 and DE441 have been generated by fittingnumerically integrated orbits to ground-based and space-based observations. Compared to theprevious general-purpose ephemerides DE430, seven years of new data have been added tocompute DE440 and DE441, with improved dynamical models and data calibration. The orbit ofJupiter has improved substantially by fitting to the Juno radio range and Very Long Baseline Array(VLBA) data of the Juno spacecraft. The orbit of Saturn has been improved by radio range andVLBA data of the Cassini spacecraft, with improved estimation of the spacecraft orbit. The orbitof Pluto has been improved from use of stellar occultation data reduced against the GAIA starcatalog. The ephemerides DE440 and DE441 are fitted to the same data set, but DE441 assumesno damping between lunar liquid core and solid mantle, which avoids a divergence when integratedbackwards in time. Therefore, DE441 is less accurate than DE440 for the current century, butcovers a much longer duration of years –13,200 to +17,191, compared to DE440 covering years1550 to 2650.名为DE440与DE441的行星与月球星历表（ephemerides），系通过将数值积分得到的轨道与地面及空间观测数据拟合生成。相较于前代通用星历表DE430，DE440与DE441新增了七年的观测数据，并采用了优化的动力学模型与数据校准方法。木星轨道的精度得到显著提升，这得益于将轨道拟合至朱诺号（Juno）探测器的无线电测距数据与甚长基线阵列（Very Long Baseline Array, VLBA）的观测数据。土星轨道的精度则通过卡西尼号（Cassini）探测器的无线电测距与甚长基线阵列（VLBA）数据得到优化，同时对探测器轨道的估计方法也进行了改进。冥王星轨道的精度提升则得益于利用基于盖亚（GAIA）星表校准的恒星掩星数据。星历表DE440与DE441基于同一套观测数据集拟合而成，但DE441未假设月球液态内核与固态幔层之间存在阻尼，这一设定避免了时间逆向积分时的发散问题。因此，DE441在当代世纪的精度略低于DE440，但其覆盖的时间跨度远大于DE440：DE440的覆盖范围为公元1550年至2650年，而DE441的覆盖范围则为公元前13200年至公元17191年。

搜集汇总

背景与挑战

背景概述

该数据集是JPL发布的DE440和DE441行星和月球星历，基于地面和空间观测数据通过数值积分轨道拟合生成，相比前代DE430增加了七年新数据并改进了动力学模型。DE440和DE441拟合相同数据，但DE441假设月球液态核心与固体地幔无阻尼，覆盖年份更长（-13,200至+17,191年），但精度略低于DE440（覆盖1550至2650年），适用于不同时间跨度的应用需求。