论文标题
从小行星（101955）Bennu的Osiris-Rex颜色图像中建模光学粗糙度和一阶散射过程
Modeling optical roughness and first-order scattering processes from OSIRIS-REx color images of the rough surface of asteroid (101955) Bennu
论文作者
论文摘要
由NASA \ TextQuoteright S Osiris-Rex Missions研究的深色小行星（101955）具有巨大的巨石且显然是贫困的表面，提供了一个自然实验室，以研究单散射过程在粗糙颗粒媒体中的作用。我们的目标是定义光学粗糙度和其他散射参数，这些参数可能可用于实验室制备样品类似物，对成像数据的解释以及将返回地球的样品的分析。我们依靠一个由数字地形模型（DTM）阴影射线追踪协助的半数统计模型来获得DTM允许的最小表面元件（\ textasciitilde {} 10 cm）的散射参数。使用马尔可夫链蒙特卡洛技术，我们在Osiris-Rex Mission \ TextQuoteright的所有四个波段图像上求解了反转问题，s textquoteright是四个候选样本站点，为此，高精度激光高度测定DTM可用。我们重建了每个参数的\ emph {a后验}概率分布，并区分了主要和次要解决方案。通过光度图像校正，我们发现低和平均粗糙度斜率的混合最能描述Bennu的表面，最高为$ 90^{\ Circ} $相位角度。我们检测到低于零的镜比，也许表明表面上暴露的亚晶体结晶夹杂物。我们报告平均粗糙度RMS斜率为$ 27 _ { - 5}^{\ circ+1} $，$ 2.6 _ { - 0.8}^{+0.1} \％$的镜比率为$ 2.6 _ { - 0.8}^{+0.1} \％$。单块反照率为$ 4.64 _ { - 0.09}^{+0.08} \％$在550 nm处，两种用于反向刻度不对称因素的解决方案，$ξ^{（1）} = -0.360总共。
The dark asteroid (101955) Bennu studied by NASA\textquoteright s OSIRIS-REx mission has a boulder-rich and apparently dust-poor surface, providing a natural laboratory to investigate the role of single-scattering processes in rough particulate media. Our goal is to define optical roughness and other scattering parameters that may be useful for the laboratory preparation of sample analogs, interpretation of imaging data, and analysis of the sample that will be returned to Earth. We rely on a semi-numerical statistical model aided by digital terrain model (DTM) shadow ray-tracing to obtain scattering parameters at the smallest surface element allowed by the DTM (facets of \textasciitilde{}10 cm). Using a Markov Chain Monte Carlo technique, we solved the inversion problem on all four-band images of the OSIRIS-REx mission\textquoteright s top four candidate sample sites, for which high-precision laser altimetry DTMs are available. We reconstructed the \emph{a posteriori} probability distribution for each parameter and distinguished primary and secondary solutions. Through the photometric image correction, we found that a mixing of low and average roughness slope best describes Bennu's surface for up to $90^{\circ}$ phase angle. We detected a low non-zero specular ratio, perhaps indicating exposed sub-centimeter mono-crystalline inclusions on the surface. We report an average roughness RMS slope of $27_{-5}^{\circ+1}$, a specular ratio of $2.6_{-0.8}^{+0.1}\%$, an approx. single-scattering albedo of $4.64_{-0.09}^{+0.08}\%$ at 550 nm, and two solutions for the back-scatter asymmetric factor, $ξ^{(1)}=-0.360\pm0.030$ and $ξ^{(2)}=-0.444\pm0.020$, for all four sites altogether.
