Ocean College, Zhejiang University, Zhoushan 316021, China.
State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China.
Sensors (Basel). 2022 Apr 7;22(8):2827. doi: 10.3390/s22082827.
Previous studies on the polarization imaging of underwater targets mainly focused on top-down detection; however, the capacities of bottom-up detection were poorly known. Based on in situ experiments, the capability of bottom-up detection of underwater targets using polarization imaging was investigated. First, to realize the objective of bottom-up polarization imaging, a SALSA polarization camera was integrated into our Underwater Polarization Imaging System (UPIS), which was integrated with an attitude sensor. At Qiandao Lake, where the water is relatively clear, experiments were conducted to examine the capacity of the UPIS to detect objects from the bottom up. Simultaneously, entropy, clarity, and contrast were adopted to compare the imaging performance with different radiation parameters. The results show that among all the used imaging parameters, the angle of polarization is the optimal parameter for bottom-up detection of underwater targets based on polarization imaging, which may result from the different diffused reflectance of the target surface to the linear polarization components of the Stokes vector.
先前关于水下目标偏振成像的研究主要集中在自上而下的探测上；然而，自下而上探测的能力却鲜为人知。本研究基于现场实验，探讨了利用偏振成像进行水下目标自下而上探测的能力。首先，为了实现自下而上偏振成像的目标，我们将 SALSA 偏振相机集成到了水下偏振成像系统（UPIS）中，该系统与姿态传感器集成在一起。在水质相对清澈的千岛湖进行实验，检验 UPIS 从底部向上探测物体的能力。同时，采用熵、清晰度和对比度来比较不同辐射参数下的成像性能。结果表明，在所使用的所有成像参数中，基于偏振成像的水下目标自下而上探测的最佳参数是偏振角，这可能是由于目标表面对 Stokes 向量的线性偏振分量的不同漫反射所致。
