Comparing Unmanned Aerial Multispectral and Hyperspectral Imagery for Harmful Algal Bloom Monitoring in Artificial Ponds Used for Fish Farming

This work aimed to assess the potential of unmanned aerial vehicle (UAV) multi- and hyper-spectral platforms estimate chlorophyll-a (Chl-a) cyanobacteria in experimental fishponds Brazil. In addition spectral resolutions, tested differ price, payload, imaging system, processing. Hyperspectral airborne surveys were conducted using a push-broom system 276-band Headwall Nano-Hyperspec camera onboard DJI Matrice 600 UAV. Multispectral global shutter-frame 4-band Parrot Sequoia Phantom 4 Water quality field measurements acquired portable fluorometer laboratory analysis. The concentration ranged from 14.3 290.7 µg/L 0 112.5 for Chl-a cyanobacteria, respectively. Forty-one bio-optical retrieval models tested. UAV hyperspectral image achieved robust assessments, with RMSE values 32.8 12.1 µg/L, images 47.6 35.1 respectively, efficiently mapping broad classes. are ideal monitoring CyanoHABs; however, integrated platform has high cost. More accessible multispectral may represent trade-off between efficiency deployment costs, provided that cameras offer narrow bands 660–690 nm 700–730 ranges 600–625 cyanobacteria.