基于无人机观测的北极冰面融池及冰面粗糙度信息提取方法研究

STUDY ON THE METHOD OF EXTRACTING ARCTIC MELT POND AND ROUGHNESS INFORMATION ON SEA ICE SURFACE BASED ON UAV OBSERVATION

北极冰面融池对于研究北极海冰质量平衡、海洋混合层热收支和盐量收支等具有重要意义。为了获得准确的融池覆盖率,本研究提出了一种利用无人机进行北极海冰融池及冰面粗糙度信息提取的方法。在第7次中国北极科学考察期间,利用无人机获取加拿大海盆周边浮冰区冰面航拍影像,针对海冰航拍图像特殊性改进了基于暗原色先验的图像去雾算法,对拼接后的航拍图像进行融池识别,计算得到航拍区域的融池覆盖率。同时利用航拍影像三维建模得到海冰表面相对高程和冰面粗糙度,继而对融池覆盖率和海冰表面粗糙度分布规律进行研究。结果表明,在本次航拍区域,海冰粗糙度大的区域具有更多小面积的融池,而融透的、面积大的融池多出现在粗糙度小的平整冰区。

Arctic melt pond over sea ice surface is of great significance in the study of Arctic sea ice mass balance and heat and salt balances in the ocean mixed layer. In order to obtain accurate melt pond fraction, this paper proposes a method for extracting Arctic melt pond and roughness information from the sea ice surface based on unmanned aerial vehicle （UAV） observations. We made UAV observations over the sea ice surface in the Canada basin during the 7th Chinese National Arctic Research Expedition. Improvment on the dark-channel- prior defogging algorithm based on the special environment of Arctic, a mosaic process ,melt pond dis-crimination on the mosaic image , and melt pond fraction calculation were done step by step. Meanwhile, we used three-dimensional aerial-image modeling to calculate the sea ice surface relative elevation and sea ice surface roughness. Study on the relationship of melt pond and sea ice surface roughness distribution showed that areas with higher surface roughness generally have more smaller melt ponds, whereas dissolved and larger melt ponds usually occur in areas with lower surface roughness.