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

目前和未来的航天器任务将很快为科学探索木星和金星的大气层提供新的机会。延长的朱诺任务(2023-2025年)的轨道最终为木星无线电掩星提供了机会。Juce(计划于2023年发射)将通过无线电科学探索木星、其环系和伽利略卫星，而新的金星探索十年将从NASA的两项任务(Veritas：Launch~2028，DaVinci，Launch~2029)和ESA enVision(Launch~2031)航天器开始。莱茵尼施研究所(RIU)在金星的远景任务和木星的果汁任务中都处于无线电掩星部分的领先地位。可靠的预测和数据处理工具对大气层无线电探测的成功至关重要，但最重要的是以前飞行任务的可靠观测数据库。这项提议的目标是：1.)将开发一个2D/3D正向光线跟踪软件包，用于预测和模拟金星和木星非球面对称大气中的射电掩星。应使用光线跟踪软件分析金星终结器对金星快车Vera无线电掩星数据集(~1,000个观测值)的影响，其中大气条件在短空间尺度上发生变化，并偏离RIU数据处理过程中假定的局部球面对称性。光线跟踪结果将被整合到金星快车Vera无线电掩星数据集中，并将导致在金星终结点进行更好的观测。光线追踪软件还将用于研究扁平的木星大气层和高度可变的电离层如何影响基于伽利略系统的木星无线电掩星观测和未来可能的朱诺无线电掩星观测。2.)应对RIU目前使用的无线电科学数据处理方法进行升级，以将金星快车Vera大气剖面的垂直分辨率提高到亚菲涅耳尺度，并从数据集中消除多径传播效应的偏差。多径传播效应也在木星大气中发生，也应从电离层伽利略射电科学观测和木星可能的Juno掩星中加以研究和消除。3.)：对有关亚菲涅尔尺度大气特征和非球面对称大气对射电掩星影响的新信息的解释将提供关于大气过程的更好的知识，为未来射电科学观测的预测提供可靠的数据基础，它们将支持大气模拟工作，并推动对金星的设想飞行任务和对木星的UUTH飞行任务的准备工作。

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.