The Geostationary Operational Environmental Satellite (GOES) Advanced Baseline Imager (ABI) is the most recent U.S. geostationary satellite and has improved resolution and potential for land surface monitoring over previous GOES sensors. The ABI reflectance has diurnal variation due to surface reflectance anisotropy that can be significant, particularly when ABI observations are sensed under hot-spot sensing conditions when the solar and viewing directions coincide. The incidence and magnitude of the hot-spot signature in geostationary satellite data has not been well documented. In this study all the available GOES-16 ABI observations acquired every 15 min in 2018, and every 10 min in 2020, over the Conterminous United States, the southern states of Canada, and the northern states of Mexico, were examined. First, hot-spot sensing conditions were identified by finding ABI 1 km observations with scattering angles (Θ) ≥ 175°, 177°, 178°, 179°, 179.9°, and 179.99°. ABI observations sensed near or in the hot-spot (Θ ≥175°) were found to occur across the study area but only over a 36 day period in the spring (days 46–81 in 2018, and 47–82 in 2020) and over a 36 or 37 day period in the autumn (days 263–299 in 2018, and 264–299 in 2020). Considering either season in each year, about 3.4%, 1.2%, 0.5%, 0.14%, 0.0015%, and 0.000015% of the daytime observations were acquired with Θ ≥175°, 177°, 178°, 179°, 179.9°, and 179.99°, respectively. For certain days up to 5.85%, 3.32%, 2.04%, 0.65%, 0.01%, and 0.0001% of the daytime ABI observations across the study area were sensed with Θ ≥ 175°, 177°, 178°, 179°, 179.9°, and 179.99°, respectively. These incidence percentages are not negligible. Even with the strictest hot-spot scattering angle definition (Θ ≥179.99°) there were 3985 and 4484 hot-spot observations sensed in the spring and autumn of 2018, and 4753 and 5252 hot-spot observations sensed in the spring and autumn of 2020. The dates, times, and locations of the 2018 and 2020 hot-spots acquired with Θ ≥179.99° are tabulated so that readers may obtain hot-spot ABI data for their own investigations. Second, the magnitude of the hot-spot reflectance in the ABI data was quantified by the difference between the ABI reflectance acquired in the hot-spot (Θ ≥179.99°) and in the ABI observations sensed immediately before and after. A total of 1833 hot-spot observations in ten geographically elliptical regions (six in 2020 and four in 2018) over land each composed of >120 ABI observations acquired where the ABI reflectance appeared to be unambiguously cloud-free, cloud shadow-free, and uncontaminated by haze or smoke, were considered. For the 2020 ABI data, the hot-spot peak was characterized by an up to 36%, 38%, 42%, and 43% increase in red (0.64 μm), near-infrared (NIR, 0.86 μm), short-wave infrared 1 (SWIR1, 1.61 μm), and SWIR2 (2.2 μm) reflectance, respectively, for a 2.48° scattering angle difference in the 10 min between successive ABI observations. For the 2018 ABI data, the hot-spot peak was characterized by an up to 43%, 46%, 47%, and 45% increase in red, NIR, SWIR1, and SWIR2 reflectance, respectively, for a 3.73° change in scattering angle in the 15 min between successive ABI observations. The magnitude of the GOES-16 ABI hot-spot is significant and given its non-negligible incidence in the spring and autumn over north America should be taken into consideration for terrestrial applications.

地球静止运行环境卫星 (GOES) 高级基线成像仪 (ABI) 是美国最新的地球静止卫星，与以前的 GOES 传感器相比，它具有更高的分辨率和地表监测潜力。由于表面反射率各向异性，ABI 反射率具有日变化，这可能是显着的，特别是当太阳和观察方向重合时，在热点感应条件下感应 ABI 观测值时。地球静止卫星数据中热点特征的发生率和幅度尚未得到充分记录。在这项研究中，检查了 2018 年每 15 分钟和 2020 年每 10 分钟在美国本土、加拿大南部各州和墨西哥北部各州获得的所有可用 GOES-16 ABI 观测结果。第一的，通过发现散射角 (Θ) ≥ 175°、177°、178°、179°、179.9° 和 179.99° 的 ABI 1 公里观测，确定了热点传感条件。发现在热点附近或在热点（θ≥175°）中感测到的 ABI 观测值发生在整个研究区域，但仅在春季超过 36 天（2018 年为 46-81 天，2020 年为 47-82 天）和秋季 36 或 37 天（2018 年为 263-299 天，2020 年为 264-299 天）。考虑到每年的任一季节，大约 3.4%、1.2%、0.5%、0.14%、0.0015% 和 0.000015% 的白天观测值是在 Θ ≥175°、177°、178°、179°、179.9°、和 179.99°，分别。在某些日子里，在整个研究区域内，高达 5.85%、3.32%、2.04%、0.65%、0.01% 和 0.0001% 的白天 ABI 观测值被感知为 Θ ≥ 175°、177°、178°、179°、179。 ° 和 179.99°，分别。这些发生率是不可忽略的。即使采用最严格的热点散射角定义（θ≥179.99°），2018年春秋两季的热点观测值分别为3985和4484个，2020年春秋的热点观测值分别为4753和5252个将θ≥179.99°获取到的2018年和2020年热点的日期、时间、地点列表，方便读者获取热点ABI数据进行自己的调查。其次，ABI 数据中热点反射率的大小通过在热点 (θ≥179.99°) 中获得的 ABI 反射率与之前和之后立即感测到的 ABI 观测值之间的差异进行量化。10 个地理椭圆区域（2020 年 6 个，2018 年 4 个）共 1833 个热点观测，每个区域由 > 考虑了 120 个 ABI 观测，其中 ABI 反射率似乎明确无云、无云影且未受雾霾或烟雾污染。对于 2020 ABI 数据，热点峰的特征是红色（0.64 μm）、近红外（NIR，0.86 μm）、短波分别增加了 36%、38%、42% 和 43%红外 1 (SWIR1, 1.61 μm) 和 SWIR2 (2.2 μm) 反射率分别为连续 ABI 观测之间 10 分钟内的 2.48° 散射角差异。对于 2018 年 ABI 数据，热点峰的特征是红色、NIR、SWIR1 和 SWIR2 反射率分别增加了 43%、46%、47% 和 45%，散射发生了 3.73°的变化连续 ABI 观察之间 15 分钟内的角度。