We present an analysis of coronal mass ejections (CMEs) observed by the Heliospheric Imagers (HIs) on board NASA's Solar Terrestrial Relations Observatory (STEREO) spacecraft. Between August 2008 and April 2014 we identify 273 CMEs that are observed simultaneously, by the HIs on both spacecraft. For each CME, we track the observed leading edge, as a function of time, from both vantage points, and apply the Stereoscopic Self-Similar Expansion (SSSE) technique to infer their propagation throughout the inner heliosphere. The technique is unable to accurately locate CMEs when their observed leading edge passes between the spacecraft, however, we are able to successfully apply the technique to 151, most of which occur once the spacecraft separation angle exceeds 180 degrees, during solar maximum. We find that using a small half-width to fit the CME can result in observed acceleration to unphysically high velocities and that using a larger half-width can fail to accurately locate the CMEs close to the Sun because the method does not account for CME over-expansion in this region. Observed velocities from SSSE are found to agree well with single-spacecraft (SSEF) analysis techniques applied to the same events. CME propagation directions derived from SSSE and SSEF analysis agree poorly because of known limitations present in the latter. This work was carried out as part of the EU FP7 HELCATS (Heliospheric Cataloguing, Analysis and Techniques Service) project (this http URL).

中文翻译：

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日光层中的 CME：III。STEREO/HI-1 对 2008 年至 2014 年在日光层探测到的 CME 应用立体几何建模技术的运动学特性进行统计分析

我们对 NASA 的日地关系天文台 (STEREO) 航天器上的日球层成像仪 (HI) 观测到的日冕物质抛射 (CME) 进行了分析。在 2008 年 8 月至 2014 年 4 月期间，我们确定了 273 个 CMEs 同时被两个航天器上的 HI 观测到。对于每个 CME，我们从两个有利位置跟踪观察到的前沿作为时间的函数，并应用立体自相似扩展 (SSSE) 技术来推断它们在整个内部日光层的传播。当观测到的 CME 在航天器之间经过时，该技术无法准确定位 CME，但是，我们能够成功地将该技术应用于 151，其中大部分发生在太阳活动极大期期间航天器分离角超过 180 度时。我们发现，使用较小的半宽来拟合 CME 会导致观测到的加速度达到非物理的高速度，而使用较大的半宽可能无法准确定位靠近太阳的 CME，因为该方法没有考虑到 CME - 在该地区扩张。发现从 SSSE 观测到的速度与应用于相同事件的单航天器 (SSEF) 分析技术非常吻合。由于 SSSE 和 SSEF 分析存在已知局限性，因此从 SSSE 和 SSEF 分析得出的 CME 传播方向不一致。这项工作是作为欧盟 FP7 HELCATS（日球层编目、分析和技术服务）项目（此 http URL）的一部分进行的。