Hoge F E, Swift R N
NASA Goddard Space Flight Center, Wallops Flight Facility, Wallops Island, Virginia 23337, USA.
Appl Opt. 1983 Dec 1;22(23):3778-86. doi: 10.1364/ao.22.003778.
Airborne depth-resolved laser-induced sea-water Raman-backscatter waveforms have been obtained along a flight line extending westward from a point approximately 30 km seaward of Assateague Island to a point where the beach was intersected at latitude 38.1 degrees N and longitude 75.2 degrees W. Pulses from a 337.1-nm nitrogen laser were repetitively transmitted vertically downward into the water column. The laser-induced water Raman backscatter pulse at 381-nm wavelength was depth (or time) resolved into forty bins having widths of -25 cm each. When converted to along-track profiles, the waveforms reveal cells of decreased Raman backscatter superimposed on an overall trend of monotonically decreasing water column optical transmission. This airborne lidar technique shows potential for (1) rapid, quantitative, synoptic study of the homogeneity of the oceanic water column and (2) measurement of the horizontal spatial distribution of the optical transmission of the upper mixed layer of the ocean. A multiple convolution model of a Gaussian transmitted pulse, Gaussian sea surface height, and slope probability density, together with an exponential-decay water-column impulse response, is shown to qualitatively account for the observed pulse shape.
沿着一条从阿萨蒂格岛向海约30公里处的一点向西延伸至北纬38.1度、西经75.2度与海滩相交点的航线，已获取了机载深度分辨激光诱导海水拉曼后向散射波形。来自337.1纳米氮激光器的脉冲被重复垂直向下发射到水柱中。波长为381纳米的激光诱导水拉曼后向散射脉冲被深度（或时间）分辨为40个间隔，每个间隔宽度为25厘米。当转换为沿航迹剖面时，波形显示出拉曼后向散射减少的区域叠加在水柱光学透射率单调下降的总体趋势上。这种机载激光雷达技术显示出在以下方面的潜力：（1）对海洋水柱均匀性进行快速、定量、全景式研究；（2）测量海洋上层混合层光学透射率的水平空间分布。一个由高斯发射脉冲、高斯海面高度和斜率概率密度组成的多重卷积模型，以及指数衰减的水柱脉冲响应，被证明能够定性地解释观测到的脉冲形状。
