The exploration of the Venus and Jupiter atmospheres by radio occultations: Extending our understanding of the planetary atmospheres beyond Fresnel scale resolution and spherical symmetry

当前和未来的航天器任务将很快为木星和金星大气层的科学探索提供新的机会。延长的朱诺任务（2023-2025）的轨道最终为木星无线电掩星提供了机会。JUICE（计划于2023年发射）将通过无线电科学探索木星、木星环系统和伽利略卫星，而新的十年金星探索将由两个NASA任务开始（VERITAS：发射~2028年，DAVINCI，发射~2029年）和ESA EnVision（发射~2031年）航天器。Rheinisches institute fr Umweltforschung （RIU）在金星的EnVision任务和木星的JUICE任务的无线电掩星部分处于领先地位。大气无线电探测成功的关键是可靠的预测和数据处理工具，但最重要的是以前任务的健全观测数据库。本提案的目标是：1)开发2D/3D正演射线追踪软件包，用于预测和模拟金星和木星非球形对称大气中的射电掩星。射线追踪软件应使用用于分析金星终结器对金星快速VeRa射电掩星数据集（约1000次观测）的影响，其中大气条件在短空间尺度上发生变化，偏离了RIU数据处理过程中假设的局部球面对称。射线追踪结果将被整合到金星快车VeRa射电掩星数据集中，并将改进金星终点站的观测。射线追踪软件还将用于研究扁平化的木星大气和高度变化的电离层如何影响基于伽利略的木星射电掩星观测和未来潜在的朱诺射电掩星。2)。应对RIU目前使用的无线电科学数据处理方法进行升级，以提高Venus Express VeRa大气剖面的垂直分辨率到亚菲涅耳尺度，并消除数据集中多径传播效应的偏差。多径传播效应也发生在木星大气中，也应该从伽利略无线电科学观测和朱诺潜在的木星掩星电离层中研究和消除。对亚菲涅耳尺度大气特征和非球形对称大气对射电掩星影响的新信息的解释，将提供对大气过程的改进认识，为未来射电科学观测预测提供良好的数据基础，支持大气建模工作，推进对金星的预想任务和木星的JUICE任务的准备工作。

Current and future spacecraft missions will soon provide new opportunities for the scientific exploration of the atmospheres of Jupiter and Venus. The orbit of the extended Juno mission (2023-2025) eventually provides opportunities for Jupiter radio occultations. JUICE (launch planned for 2023) will explore Jupiter, its ring system, and the Galilean moons by radio science, while the new decade of Venus exploration will begin with two NASA missions (VERITAS: launch ~2028, DAVINCI, launch ~2029) and the ESA EnVision (launch ~2031) spacecraft. The Rheinisches Institut für Umweltforschung (RIU) is in leading position for the radio occultation part of both the EnVision mission at Venus and the JUICE mission at Jupiter. Crucial for the success of the atmospheric radio sounding are reliable prediction and data processing tools, but most important, a sound observation database from previous missions. The objectives of this proposal are: 1.) A 2D/3D forward raytracing software package shall be developed for the prediction and simulation of radio occultations in the non-spherical symmetric atmospheres of Venus and Jupiter. The raytracing software shall be used to analyze the effect of the Venus terminator on the Venus Express VeRa radio occultation data set (~1,000 observations), where atmospheric conditions change over short spatial scales and deviate from the local spherical symmetry assumed during data processing at RIU. The raytracing results shall be integrated in the Venus Express VeRa radio occultation data set and will lead to improved observations at the Venus terminator. The raytracing software shall also be used to study how the oblate Jovian atmosphere and the highly variable ionosphere affect radio occultation observations at Jupiter based on Galileo and the potential future Juno radio occultations. 2.) An upgrade of the currently used radio science data processing method at RIU shall be applied to increase the vertical resolution of the Venus Express VeRa atmospheric profiles to sub-Fresnel scales and remove the bias of multipath propagation effects from the data set. Multipath propagation effects occur also in the Jovian atmosphere and shall also be investigated and removed from the ionospheric Galileo radio science observations and the potential Juno occultations for Jupiter. 3.): The interpretation of the new information about sub-Fresnel scale atmospheric features and the effect of non-spherical symmetric atmospheres on radio occultations shall provide improved knowledge about atmospheric processes, a sound data base for the prediction of future radio science observation, they shall support atmospheric modeling efforts and advance the preparation for the EnVision mission to Venus and the JUICE mission to Jupiter.