Characterizing a New England Saltmarsh with NASA G-LiHT Airborne Lidar
Characterizing a New England Saltmarsh with NASA G-LiHT Airborne Lidar
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DOI：
10.3390/rs11050509
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发表时间：
2019-03
期刊：
影响因子：
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通讯作者：
Ian Paynter;C. Schaaf;J. Bowen;L. Deegan;F. Peri;B. Cook
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文献类型：
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作者：
Ian Paynter;C. Schaaf;J. Bowen;L. Deegan;F. Peri;B. Cook
机载激光雷达可以在区域尺度上观测盐沼，针对物候和潮汐状态提供信息，以便更有效地利用频繁的多光谱卫星观测来监测变化。NASA戈达德激光雷达高光谱和热成像（G-LiHT）对盐沼地区（美国马萨诸塞州Plum Island）进行了多年（2014年、2015年和2016年）的机载激光雷达观测。这些机载激光雷达数据提供了重要盐沼成分的特征，以及有效调查的规范。芦苇入侵面积从2014年的8374 m2增加到2015年的8882 m2(+6.1%)， 2016年再次增加到13819 m2（+55.6%）。地面激光雷达的验证支持了这一增长，但表明总范围仍被低估。机载激光雷达对互花米草覆盖范围的估计值与地面激光雷达的估计值相差不超过7%，但对互花米草高度的估计过高（+83.9%）。发现捕获藻类需要在最低点±15°范围内观察，捕获溪流结构需要在最低点±10°范围内观察。此外，在机载激光雷达数据中成功捕获了90.33%的小溪和沟渠（航空图像中发现的9084.3米中有8206.3米）。
Airborne lidar can observe saltmarshes on a regional scale, targeting phenological and tidal states to provide the information to more effectively utilize frequent multispectral satellite observations to monitor change. Airborne lidar observations from NASA Goddard Lidar Hyperspectral and Thermal (G-LiHT) of a well-studied region of saltmarsh (Plum Island, Massachusetts, United States) were acquired in multiple years (2014, 2015 and 2016). These airborne lidar data provide characterizations of important saltmarsh components, as well as specifications for effective surveys. The invasive Phragmites australis was observed to increase in extent from 8374 m2 in 2014, to 8882 m2 in 2015 (+6.1%), and again to 13,819 m2 in 2016 (+55.6%). Validation with terrestrial lidar supported this increase, but suggested the total extent was still underestimated. Estimates of Spartina alterniflora extent from airborne lidar were within 7% of those from terrestrial lidar, but overestimation of height of Spartina alterniflora was found to occur at the edges of creeks (+83.9%). Capturing algae was found to require observations within ±15° of nadir, and capturing creek structure required observations within ±10° of nadir. In addition, 90.33% of creeks and ditches were successfully captured in the airborne lidar data (8206.3 m out of 9084.3 m found in aerial imagery).