论文标题
部分可观测时空混沌系统的无模型预测
An astrometric mass estimate for asteroid (223) Rosa
论文作者
论文摘要
储层计算是预测湍流的有力工具，其简单的架构具有处理大型系统的计算效率。然而，其实现通常需要完整的状态向量测量和系统非线性知识。我们使用非线性投影函数将系统测量扩展到高维空间，然后将其输入到储层中以获得预测。我们展示了这种储层计算网络在时空混沌系统上的应用，该系统模拟了湍流的若干特征。我们表明，使用径向基函数作为非线性投影器，即使只有部分观测并且不知道控制方程，也能稳健地捕捉复杂的系统非线性。最后，我们表明，当测量稀疏、不完整且带有噪声，甚至控制方程变得不准确时，我们的网络仍然可以产生相当准确的预测，从而为实际湍流系统的无模型预测铺平了道路。
Outer main belt asteroid (223) Rosa is a possible flyby target of opportunity for ESA's (European Space Agency) JUpiter ICy moons Explorer (JUICE) mission when passing the asteroid belt on the way to Jupiter. The very low albedo and the featureless red spectra indicate a P-type asteroid in the Tholen taxonomy, though the yet known bulk density did not match very well this classification. Aim of this work was to derive new estimates for the mass and for the bulk density for (223) Rosa. The mass of Rosa was derived by analyzing the gravitational deflection of small `test' asteroids which had a close encounter with Rosa in the past. To find such events suitable for the mass determination, an encounter search with about 900,000 asteroids over the time span $1980-2030$ was performed. Three encounters were identified from which two independent mass estimates for Rosa were derived: $M = (5.32 \pm 2.17) \times 10^{17}$ kg and $M = (3.15 \pm 1.14) \times 10^{17}$ kg, respectively. The weighted mean is $M = (3.62 \pm 1.25) \times 10^{17}$ kg. This yields to a bulk density of $ρ= 1.2 \pm 0.5 \mathrm{\,g\,cm^{-3}}$, when adopting an effective diameter of $D = 83 \pm 8$ km. This bulk density estimate is consistent with typical densities for Tholen taxonomy P-type asteroids.
