Single spacecraft missions do not measure the pristine solar wind continuously because of the spacecrafts' orbital trajectory. The infrequent spatiotemporal cadence of measurement fundamentally limits conclusions about solar wind-magnetosphere coupling throughout the solar system. At Mars, such single spacecraft missions result in limitations for assessing the solar wind's role in causing lower altitude observations such as auroral dynamics or atmospheric loss. In this work, we detail the development of a virtual solar wind monitor from the Mars Atmosphere and Volatile Evolution (MAVEN) mission; a single spacecraft. This virtual solar wind monitor provides a continuous estimate of the solar wind upstream from Mars with uncertainties. We specifically employ Gaussian process regression to estimate the upstream solar wind and uncertainty estimations that scale with the data sparsity of our real observations. This proxy enables continuous solar wind estimation at Mars with representative uncertainties for the majority of the time since since late 2014. We conclude by discussing suggested uses of this virtual solar wind monitor for statistical studies of the Mars space environment and heliosphere.

翻译：单航天器任务因其轨道轨迹无法持续测量原始太阳风。这种测量在时空上的不连续性从根本上限制了对整个太阳系中太阳风-磁层耦合的结论推断。在火星探测任务中，此类单航天器任务导致评估太阳风在引发低空观测现象（如极光动力学或大气逃逸）中的作用存在局限。本研究详细阐述了基于单航天器任务——火星大气与挥发物演化（MAVEN）任务——构建虚拟太阳风监测器的开发工作。该虚拟太阳风监测器可提供火星上游太阳风的连续估计值及其不确定性。我们特别采用高斯过程回归来估计上游太阳风，其不确定性评估会随实际观测数据的稀疏程度进行缩放。该代理方法能够为2014年末以来大部分时间段提供具有代表性不确定性的火星太阳风连续估计。最后，我们讨论了该虚拟太阳风监测器在火星空间环境与日球层统计研究中的建议应用。