Deep learning-based super-resolution for harmful algal bloom monitoring of inland water

Do Hyuck Kwon, Seok Min Hong, Ather Abbas, Sanghyun Park, Gibeom Nam, Jae Hyun Yoo, Kyunghyun Kim, Hong Tae Kim, Jong Cheol Pyo*, Kyung Hwa Cho

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Inland water frequently occurs during harmful algal blooms (HABs), rendering it challenging to comprehend the spatiotemporal features of algal dynamics. Recently, remote sensing has been applied to effectively detect the algal spatiotemporal behaviors in expensive water bodies. However, image sensor resolution limitation can render the understanding of spatiotemporal features of relatively small water bodies challenging. In addition, few studies have improved the resolution of remote sensing images to investigate inland water quality, owing to the image sensor resolution limitations. Therefore, this study applied deep learning-based Super-resolution for transforming satellite imagery of 20 m to airborne imagery of 5 m. After performing atmospheric correction for the acquired images, we adopted super-resolution (SR) methodologies using a super-resolution convolutional neural network (SRCNN) and super-resolution generative adversarial networks (SRGAN) to estimate the Chlorophyll-a (Chl-a) concentration in the Geum River of South Korea. Both methods generated SR images with water reflectance at 665, 705, and 740 nm. Then, two band-ratio algorithms at 665 and 740 nm wavelengths were applied to the reflectance images to estimate the Chl-a concentration maps. The SRCNN model outperformed SRGAN and bicubic interpolation with peak signal-to-noise ratios (PSNR), mean square errors (MSE), and structural similarity index measures (SSIM) for the validation dataset of 24.47 (dB), 0.0074, and 0.74, respectively. SR maps from the SRCNN provided more detailed spatial information on Chl-a in the Geum River compared to the information obtained from satellite images. Therefore, these findings showed the potential of deep learning-based SR algorithms by providing further information according to the algal dynamics for inland water management with remote sensing images.

Original languageEnglish (US)
Article number2249753
JournalGIScience and Remote Sensing
Issue number1
StatePublished - 2023

Bibliographical note

Funding Information:
This research was supported by the Water Environmental and Infrastructure Research Program (NIER-2021-01-01-058) funded by the National Institute of Environmental Research. This work is also partially supported by MSIT through Sejong Science Fellowship, funded by National Research Foundation of Korea (NRF) [No.2021R1C1C2010703].

Publisher Copyright:
© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.


  • Chlorophyll-a
  • convolutional neural network (CNN)
  • generative adversarial network (GAN)
  • remote sensing
  • Super-resolution

ASJC Scopus subject areas

  • General Earth and Planetary Sciences


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