Space‐based optical lightning sensors including the lightning imaging sensor (LIS) and geostationary lightning mapper (GLM) are pixelated imagers that detect lightning as transient increases in cloud top illumination. Detection requires optical emissions to escape the cloud top to space with sufficient energy to trigger a pixel on the imaging array. Through scattering and absorption, certain clouds are able to block most light from reaching the instrument, causing a reduction in detection efficiency (DE) and possibly location accuracy (LA). Radiant lightning emissions that illuminate large cloud top areas are used to examine scenarios where clouds block light from reaching orbit. In some cases, these anomalies in the spatial radiance distribution from the lightning pulse lead to “holes” in the optical lightning flash where certain pixels fail to trigger. Such holes are identified algorithmically in the Tropical Rainfall Measuring Mission satellite LIS record and the microphysical properties of the coincident storm region are queried. We find that holes primarily occur in tall (IR T_b < 235 K) convection (87%) and overhanging anvil clouds (10%). The remaining 3% of holes occur in moderate‐to‐weak convection or in clear air breaks between stormclouds. We further demonstrate how an algorithm that assesses the spatial radiance patterns from energetic lightning pulses might be used to construct an optical transmission gridded stoplight product for GLM that could help operators identify clouds with a potentially reduced DE and LA.

中文翻译：

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光学闪电中的孔：识别闪电成像器数据中的透射差的云

包括雷电成像传感器（LIS）和对地静止雷电测绘仪（GLM）在内的天基光学雷电传感器是像素化成像仪，可随着云顶照明的瞬态增加而检测闪电。检测需要光发射，以足够的能量使云顶逃逸到太空，从而触发成像阵列上的像素。通过散射和吸收，某些云将能够阻挡大多数光线到达仪器，从而导致检测效率（DE）以及位置精度（LA）降低。照亮较大的云层顶部区域的辐射雷电用于检查云层阻挡光线到达轨道的场景。在某些情况下，这些来自雷电脉冲的空间辐射分布的异常会导致某些像素无法触发的光学雷电中的“空洞”。在热带降雨测量任务卫星LIS记录中通过算法识别了此类漏洞，并查询了一致风暴区域的微物理性质。我们发现孔主要出现在高处（IRT _b  <235 K）对流（87％）和悬垂的砧云（10％）。其余3％的空洞发生在中弱对流或暴风云之间的晴朗空气中。我们进一步演示了如何从高能雷电脉冲中评估空间辐射度模式的算法可用于构建GLM的光传输网格停车灯产品，该产品可以帮助运营商识别出具有潜在降低的DE和LA的云。