Cloud‐top heights (CTH) from the Multiangle Imaging Spectroradiometer (MISR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra constitute our longest‐running single‐platform CTH record from a stable orbit. Here, we provide the first evaluation of the Terra Level 2 CTH record against collocated International Space Station Cloud‐Aerosol Transport System (CATS) lidar observations between 50ºN and 50ºS. Bias and precision of Terra CTH relative to CATS is shown to be strongly tied to cloud horizontal and vertical heterogeneity and altitude. For single‐layered, unbroken, optically thick clouds observed over all altitudes, the uncertainties in MODIS and MISR CTH are −540 ± 690 m and −280 ± 370 m, respectively. The uncertainties are generally smaller for lower altitude clouds and larger for optically thin clouds. For multi‐layered clouds, errors are summarized herein using both absolute CTH and CATS‐layer‐altitude proximity to Terra CTH. We show that MISR detects the lower cloud in a two‐layered system, provided top‐layer optical depth <∼0.3, but MISR low‐cloud CTH errors are unaltered by the presence of thin cirrus. Systematic and random errors are propagated to explain inter‐sensor disagreements, as well as to provide the first estimate of the MISR stereo‐opacity bias. For MISR, altitude‐dependent wind‐retrieval bias (−90 to −110 m) and stereo‐opacity bias (−60 to −260 m) and for MODIS, CO₂‐slicing bias due to geometrically thick cirrus leads to overall negative CTH bias. MISR’s precision is largely driven by precision in retrieved wind‐speed (3.7 m s⁻¹), whereas MODIS precision is driven by forward‐modeling uncertainty.

中文翻译：

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通过与ISS-CATS Lidar的比较对Terra-MODIS和MISR云顶高度进行评估和误差分析

Terra上的多角度成像光谱仪（MISR）和中分辨率成像光谱仪（MODIS）的云顶高度（CTH）构成了我们从稳定轨道出发运行时间最长的单平台CTH记录。在这里，我们针对在50ºN和50ºS之间并置的国际空间站云气溶胶传输系统（CATS）激光雷达观测结果，对Terra 2级CTH记录进行了首次评估。相对于CATS，Terra CTH的偏差和精度与云的水平和垂直异质性和高度密切相关。对于在所有高度上观测到的单层，连续，光学厚的云，MODIS和MISR CTH的不确定度分别为-540±690 m和-280±370 m。对于低海拔云，不确定性通常较小，而对于光学薄云，不确定性较大。对于多层云，此处使用绝对CTH和CATS层高度与Terra CTH的接近度来总结错误。我们表明，只要顶层光学深度<〜0.3，MISR就能在两层系统中检测到较低的云层，但是薄卷云的存在不会改变MISR低云层CTH的误差。传播系统误差和随机误差以解释传感器之间的分歧，并提供对MISR立体不透明性偏差的首次估计。对于MISR，取决于海拔的回风偏差（−90至-110 m）和立体不透明度偏差（−60至−260 m），而对于MODIS，CO 但是MISR低云CTH错误不会因为细卷云的存在而改变。传播系统误差和随机误差以解释传感器之间的分歧，并提供对MISR立体不透明性偏差的首次估计。对于MISR，取决于海拔的回风偏差（−90至-110 m）和立体不透明度偏差（−60至−260 m），而对于MODIS，CO 但是MISR低云CTH错误不会因为细卷云的存在而改变。传播系统误差和随机误差以解释传感器之间的分歧，并提供对MISR立体不透明性偏差的首次估计。对于MISR，取决于海拔的回风偏差（−90至-110 m）和立体不透明度偏差（−60至−260 m），而对于MODIS，CO由于几何形状的卷云而造成的₂切片偏差会导致整体CTH偏差为负。MISR的精度很大程度上取决于获得的风速（3.7 ms ^-1），而MODIS的精度则取决于正向建模的不确定性。