Journal of Tropical Oceanography ›› 2022, Vol. 41 ›› Issue (3): 46-53.doi: 10.11978/2021088CSTR: 32234.14.2021088

• Oceanographic Research and Observation • Previous Articles     Next Articles

Remote sensing estimation of green macroalgae Ulva pertusa based on unmanned aerial vehicle and satellite image

MENG Miaomiao1,2,3(), ZHENG Xiangyang1,2,3, XING Qianguo1,2,3(), LIU Hailong1,2,3   

  1. 1. CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China
    2. Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
    3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2021-07-09 Revised:2021-09-02 Published:2021-09-19
  • Contact: XING Qianguo E-mail:mmeng@yic.ac.cn;qgxing@yic.ac.cn
  • Supported by:
    National Natural Science Foundation of China(42076188);National Natural Science Foundation of China(41676171);The Strategic Priority Research Program of the Chinese Academy of Sciences(XDA1906000);The Strategic Priority Research Program of the Chinese Academy of Sciences(XDA19060203);The Strategic Priority Research Program of the Chinese Academy of Sciences(XDA19060501);The Instrument Developing Project of the Chinese Academy of Sciences(YJKYYQ20170048)

Abstract:

Satellite images are valuable data sources for monitoring floating green macroalgae on the sea surface. However, there are large errors in green macroalgae coverage derived on mixed pixels. It is thus important to solve the problem of sub-pixel coverage of green macroalgae, for precise monitoring of benthic green macroalgae in coastal area. In this paper, retrieval models were established to link sub-pixel coverage of green macroalgae with vegetation indexes and reflectance of characteristic bands by analyzing spectral characteristics of green macroalgae from the Landsat images, based on the results of green macroalgae coverage derived from unmanned aerial vehicle (UAV). The results show excellent linear relationships between the reflectance of blue, green, and red bands and the sub-pixel coverage of green macroalgae, and the reflectance decreases monotonically with increasing sub-pixel coverage. These three models were verified, and the results show that the model based on the reflectance of green band was more accuracy than the other indexes or index combination, with the highest coefficient of determination (R2), root mean square error (RMSE), and mean relative error (MRE) values of 0.92, 0.07, and 10.85%, respectively. Hence, we provide a model that can estimate the sub-pixel coverage of green macroalgae, and realize the precise monitoring of the coverage of green macroalgae extracted from Landsat images.

Key words: unmanned aerial vehicle (UAV), satellite image, green macroalgae, sub-pixel coverage

CLC Number: 

  • X87