Influence of solar and sensor angles on chlorophyll estimation for geostationary ocean color imager

The impact of the solar and sensor angles on band-ratio chlorophyll concentration (Chl) estimation in Case 1 waters (open ocean) is analyzed in this work. The error range of Chl estimation due to angular variation is evaluated. The radiative transfer code Hydrolight is used for remote sensing reflectance simulation for 20 spectral bands. OC4v4 algorithm is used for Chl estimation. The results indicate that the error range of Chl estimation is between -41.91% and +46.15% when Chl range is from 0.0425 mg/m3 to 10.6685 mg/m3 and the solar and sensor zenith angles vary between 0 and 80°. This study provides a reference to determine the effective observation area of a future multispectral or hyperspectral geostationary ocean color sensor.

[1]  B. Gentili,et al.  Diffuse reflectance of oceanic waters. III. Implication of bidirectionality for the remote-sensing problem. , 1996, Applied optics.

[2]  Charles H. Mazel,et al.  The spectral upwelling radiance distribution in optically shallow waters , 2003 .

[3]  Pierre Gouton,et al.  Simulation of Future Geostationary Ocean Color Images , 2012, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing.

[4]  B Gentili,et al.  Diffuse reflectance of oceanic waters. II Bidirectional aspects. , 1993, Applied optics.

[5]  B Gentili,et al.  Diffuse reflectance of oceanic waters: its dependence on Sun angle as influenced by the molecular scattering contribution. , 1991, Applied optics.

[6]  M. Kahru,et al.  Ocean Color Chlorophyll Algorithms for SEAWIFS , 1998 .

[7]  F. Gohin,et al.  A five channel chlorophyll concentration algorithm applied to SeaWiFS data processed by SeaDAS in coastal waters , 2002 .

[8]  V. Vantrepotte,et al.  Effect of inherent optical properties variability on the chlorophyll retrieval from ocean color remote sensing: an in situ approach. , 2010, Optics express.

[9]  C. Lorenzen,et al.  Spectra of Backscattered Light from the Sea Obtained from Aircraft as a Measure of Chlorophyll Concentration , 1970, Science.

[10]  Chuanmin Hu,et al.  Validation of SeaWiFS chlorophyll a concentrations in the Southern Ocean: A revisit , 2006 .

[11]  R. W. Austin.  The remote sensing of spectral radiance from below the ocean surface , 1974 .

[12]  M. Pinkerton,et al.  Validation of SeaWiFS data from around New Zealand , 2004 .

[13]  F. D’Ortenzio,et al.  Validation of empirical SeaWiFS algorithms for chlorophyll-a retrieval in the Mediterranean Sea: A case study for oligotrophic seas , 2002 .

[14]  M. Pinkerton,et al.  Intercomparison of ocean colour band-ratio algorithms for chlorophyll concentration in the Subtropical Front east of New Zealand , 2005 .

[15]  André Morel,et al.  Non-isotropy of the upward radiance field in typical coastal (Case 2) waters , 2001 .