DBPapers
DOI: 10.5593/SGEM2016/B22/S10.123

MEASUREMENTS OF CHLOROPHYLL-A IN VIVO FLUORESCENCE AND WATER REFLECTANCE BY CONSUMER DIGITAL CAMERAS FOR REMOTE SENSING DATA VERIFICATION

V.Povazhnyy, A.Povazhnyy, A. Zolotareva
Thursday 8 September 2016 by Libadmin2016

References: 16th International Multidisciplinary Scientific GeoConference SGEM 2016, www.sgem.org, SGEM2016 Conference Proceedings, ISBN 978-619-7105-59-9 / ISSN 1314-2704, June 28 - July 6, 2016, Book2 Vol. 2, 963-970 pp

ABSTRACT
Two modifications of consumer digital cameras were proposed, allowing for quick
assessments of chlorophyll-A concentration in case II waters during the ground truth
campaigns. To measure chlorophyll-A in vivo fluorescence, the images in highsensitivity mode (ISO 6400) were taken through red (> 650 nm) glass filter with
flashlight excitation through blue glass (450 nm) filter in dark chamber of 1l-volume.
The digital brightness of selected part of JPEG-processed images was recorded in red
channel and the sensitivity up to 1,0 ug/l was reached with inexpensive device. To
measure water reflectance in red and NIR regions for the satellite NIR-algorithms
verification, the images of the water surface were taken in normal mode (ISO 100)
through polarizing filter, equipped with red (>620 nm) and NIR (>730 nm) film filters.
The white plate for standard reflectance was pictured on every scene. The digital
brightness for the red and NIR parts of JPEG images was recorded in red channel, the
NIR values were subtracted from red ones to yield the reflectance in 620 – 730 band and NIR to red reflectance relation was compared with chlorophyll-A and TSS values in
situ. The good agreement with TSS and Secchi depth data was obtained for NIR
reflectance, while the chlorophyll assessments proved to be reliable for high (> 30 ug/l)
summer bloom concentrations. The progress of consumer digital cameras allows for
future development of reliable cloud-based algorithms for ground truth and water
quality monitoring.

Keywords: chlorophyll-A, fluorescence, reflectance, digital camera