A Semi-analytical Approach to Understand Remote Sensing-based Backscattering Characteristics for Kerala Coast Using In Situ Observation

  • Shafique Matin
  • Sisir Kumar Dash
  • Tune Usha


A quasi-analytical algorithm (QAA)-based distribution and variability of particulate backscattering coefficient (bbp) was studied for Kerala coast, India. A total of 28 observations were made in the coastal stretch of about 410 km from Kasaragod to Ernakulam for up to 50 m depth. Optical data were collected using a hyperspectral underwater radiometer to evaluate the bbp, water-leaving radiance (Lw) and chlorophyll-a (Chl-a) concentration. We aimed to achieve three objectives, i.e. (1) QAA-based bbp calculation using underwater radiometer and its sensitivity to downwelling irradiance (Ed) and surface radiance (Es), (2) validation of the relationship between bbp and Chl-a concentration for inshore and offshore coastal waters and (3) the relationship of Lw with QAA-based bbp and in situ Chl-a. We observed that the range of bbp values varied between 0.07 and 0.002 m−1, with a maximum bbp value between 1200 and 1400 h for inshore waters. Ed and Es are independent variables and were placed at the denominator to calculate bbp, where Ed is found relatively more sensitive than Es. The correlation between bbp and Chl-a found growing with depth (< 20 m R2: 0.067, > 20 m R2: 0.487), due to the increasing complexity of coastal waters (Case II). While relating the Chl-a and bbp with Lw, showed a poor corleation with a low R2 value of 0.229 and 0.203, respectively, signifying the maximum scattering due to other suspended matters with less contribution from Chl-a pigment in highly turbid coastal waters.


Quasi-analytical algorithm Hyperspectral radiometer Remote sensing reflectance Backscattering coefficient Chlorophyll-a 



The authors are thankful to Project Director of ICMAM in facilitating the work.


  1. Boss E, Stramski D, Bergmann T, Pegau WS, Lewis M (2004) Why should we measure the optical backscattering coefficient? Oceanography 17:44–49CrossRefGoogle Scholar
  2. Claustre H, Bishop J, Boss E, Bernard S, Berthon JF, Coatanoan C, Johnson K, Lotiker A, Ulloa A, Perry MJ, D’Ortenzio F, D’andon OHF, Uitz J (2010) Bio-optical profiling floats as new observational tools for biogeochemical and ecosystem studies- Proceedings of oceanObs’09: sustained ocean observations and information for society (Vol. 2), Venice, ItalyGoogle Scholar
  3. Deidun A, Drago A, Gauci A, Galea A, Azzopardi J, Mélin F (2011) A first attempt at testing correlation between MODIS Ocean colour data and in situ chlorophyll-a measurements within Maltese coastal waters. Proc of SPIE 8175:1–8Google Scholar
  4. Dickey TD (2003) Emerging ocean observations for interdisciplinary data assimilation systems. J Mar Syst, 40– 41C, 5–48CrossRefGoogle Scholar
  5. Gordon HR, Morel A (1983) Remote assessment of ocean color for interpretation of satellite visible imagery: a review (eds: Barber RT, Mooers CNK, Bowman MJ, Zeitzschel B). Springer, New YorkGoogle Scholar
  6. Gordon HR, Brown OB, Evans RH, Brown JW, Smith RC, Baker KS, Clarks DK (1988) A semianalytic radiance model of ocean color. J Geophys Res 93:10909–10924CrossRefGoogle Scholar
  7. Graff JR, Westberry TK, Milligan AJ, Brown MB, Dall’Olmo G, van Dongen-Vogels V, Reifel KM, Behrenfeld MJ (2015) Analytical phytoplankton carbon measurements spanning diverse ecosystems. Deep-Sea Res Pt I 102:16–25Google Scholar
  8. Hu C, Feng L, Lee ZP (2013) Uncertainties of SeaWiFS and MODIS remote sensing reflectance: implications from clear water measurements. Remote Sens Environ 133:168–182CrossRefGoogle Scholar
  9. Kostadinov TS, Siegel DA, Maritorena S (2010) Global variability of phytoplankton functional types from space: assessment via the particle size distribution. Biogeosciences 7:3239–3257CrossRefGoogle Scholar
  10. Latha TP, Nagamani PV, Rao BS, Amarendra K, Rao KH, Choudhury SB, Dash SK (2013) Particle backscattering variability in the coastal waters of Bay of Bengal: a case study along off Kakinada and Yanam regions. Geosci Remote Sens Lett 10(6):1517–1521CrossRefGoogle Scholar
  11. Lee ZP, Hu C (2006) Global distribution of case-1 waters: an analysis from SeaWiFS measurements. Remote Sens Environ 101:270–276CrossRefGoogle Scholar
  12. Lee ZP, Carder KL, Peacock TG, Davis CO, Mueller JL (1996) Method to derive ocean absorption coefficients from remote-sensing reflectance. Appl Opt 35(3):453–462CrossRefGoogle Scholar
  13. Lee ZP, Carder KL, Arnone R (2002) Deriving inherent optical properties from water color: a multi-band quasi-analytical algorithm for optically deep waters. Appl Opt 41:5755–5772CrossRefGoogle Scholar
  14. Lee ZP, Carder KL, Mobley CD, Steward RG, Patch JS (1999) Hyperspectral remote sensing for shallow waters: 2. Deriving bottom depths and water properties by optimization. Appl Opt 38:3831–3843CrossRefGoogle Scholar
  15. Li S, Song K, Mu G, Zhao Y, Ma J, Ren J (2016) Evaluation of the quasi-analytical algorithm (QAA) for estimating Total absorption coefficient of turbid inland waters in Northeast China. Appl Earth Observ Remote Sens 9(9):4022–4036CrossRefGoogle Scholar
  16. Loisel H, Meriare X, Berthan, Poteau A (2007) Investigation of the optical back scattering ratio of marine particles in relation to their biogeochemical composition in the eastern English Channel and southern North Sea. Limnol Oceanogr 52(2):739–752CrossRefGoogle Scholar
  17. Morel A (1988) Optical modeling of the upper ocean in relation to its biogenous matter content (case I waters). J Geophys Res 93:10749–10768CrossRefGoogle Scholar
  18. Morel A, Maritorena S (2001) Bio-optical properties of oceanic waters: a reappraisal. J Geophys Res 106:7163–7180CrossRefGoogle Scholar
  19. Nechad, B., Dogliotti, A., Ruddick, K., Doxaran, D. (2016) Particulate backscattering and suspended matter concentration retrieval from remote-sensed turbidity in various coastal and riverine turbid waters. In: Proceedings of ESA living planet symposium, Prague, 9–13 May 2016, ESA-SP 740Google Scholar
  20. Riser SC, Johnson KS (2008) Net production of oxygen in the subtropical ocean. Nature 451(7176):323–325CrossRefGoogle Scholar
  21. Seo H, Xie SP, Murtugudde R, Jochum M, Miller AJ (2009) Seasonal effects of Indian Ocean freshwater forcing in a regional coupled model. J Clim 22:6577–6596CrossRefGoogle Scholar
  22. Smith RC, Baker KS (1981) Optical properties of the clearest natural waters. Appl Opt 20:177–184CrossRefGoogle Scholar
  23. Stramski D, Boss E, Bogucki D, Voss KJ (2004) The role of seawater constituents in light backscattering in the ocean. Prog Oceanogr 61:27–56CrossRefGoogle Scholar
  24. Whitmire AL, Boss E, Cowles TJ, Pegau WS (2007) Spectral variability of the particulate backscattering ratio. Opt Express 15(11):7022CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Shafique Matin
    • 1
  • Sisir Kumar Dash
    • 2
  • Tune Usha
    • 2
  1. 1.Teagasc Food Research CentreAshtownIreland
  2. 2.National Centre for Coastal Research (NCCR)Pallikaranai, ChennaiIndia

Personalised recommendations