空间分辨率对水深遥感反演的影响分析

遥感水深反演中空间分辨率的影响是一个重要的科学问题。本文使用东岛的QuickBird和WorldView-2多光谱影像及实测水深点进行实验研究，实验使用了原始空间分辨率（2.4/2m）以及4种降空间分辨率（4m，8m，16m和32m）的影像，使用相同的水深控制点开展水深遥感反演，并对水深反演结果使用相同的检查点进行精度验证。实验结果表明，随着空间分辨率由2.4/2m降低至4m，8m和16m，水深遥感反演的精度呈现出逐渐提高的趋势，进一步降低空间分辨率则会导致水深反演精度下降。当影像空间分辨率为16m时，水深反演结果误差最小且与实测水深值相关性最高，此时两景影像的水深反演平均相对误差分别21.2%和13.1%，相对于最大值分别降低了14.7%和2.9%；平均绝对误差分别为2.0m和1.4m，相对于最大值分别降低了1.0m和0.5m。本文研究结果为水深遥感反演研究与应用中遥感数据的选择提供了参考。

A spatial resolution effect analysis of remote sensing bathymetry

A spatial resolution effect of remote sensing bathymetry is an important scientific problem. The in situ measured water depth data and images of Dongdao Island are used to study the effect of water depth inversion from different spatial resolution remote sensing images. The research experiments are divided into five groups including QuickBird and WorldView-2 remote sensing images with their original spatial resolution (2.4/2.0 m) and four kinds of reducing spatial resolution (4, 8, 16 and 32 m), and the water depth control and checking points are set up to carry out remote sensing water depth inversion. The experiment results indicate that the accuracy of the water depth remote sensing inversion increases first as the spatial resolution decreases from 2.4/2.0 to 4, 8 and 16 m. And then the accuracy decreases along with the decreasing spatial resolution. When the spatial resolution of the image is 16 m, the inversion error is minimum. In this case, when the spatial resolution of the remote sensing image is 16 m, the mean relative errors (MRE) of QuickBird and WorldView-2 bathymetry are 21.2% and 13.1%, compared with the maximum error are decreased by 14.7% and 2.9% respectively; the mean absolute errors (MAE) are 2.0 and 1.4 m, compared with the maximum are decreased by 1.0 and 0.5 m respectively. The results provide an important reference for the selection of remote sensing data in the study and application of the remote sensing bathymetry.