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Coastal and Ocean Optical Remote Sensing Group

The Coastal and Ocean Optical Remote Sensing Laboratory (ORS Lab) is an effort by a broad community of interdisciplinary scientists to study the interaction of light with the ocean and its constituents. The Coastal and Ocean ORS Lab is part of the NOAA-CREST Center at CCNY. The laboratory is located in Room 553 of The Grove School of Engineering, 140th St. & Convent Ave. New York, NY 10031.

Interests

  • Improvement of algorithms for remote sensing for oceanic and coastal areas.
  • Tracking of harmful algal blooms (HAB).
  • Participation in a network of observing platforms for cal/val of satellite oceanic products (AERONET-OC).
  • Oceanographic instrument design and development - focused on the spectral and angular changes of the underwater polarized light.
  • Field work and data processing in marine optics (Chesapeake Bay (2005), Sapelo Island, GA (2006), Long Island Sound, Peconic Bay, New York Harbor, Hudson River (2004 - 2009), Sandy Hook, NJ (2008 - 09), Norfolk, VA (2009), Puerto Rico (2004 - 09), Gulf of Mexico, TX (2010)).
  • Coupled atmospheric/oceanic radiative transfer (scalar and vectorial).
  • Coastal flow modeling for the NY/NJ estuary.

Goals

The purpose of the Coastal and Ocean ORS Lab at the NOAA-CREST Center is to monitor and investigate the optical properties of complex coastal areas as well as clear open ocean waters. This is accomplished with remotely-sensed data, received from operational and research satellites, observing platforms and in site data. 

People

  • Sam Ahmed  - Herbert Kayser Professor - Professor of Electrical Engineering, Laboratory Director,
  • Alex Gilerson - Associate Professor of Electrical Engineering,
  • Maria Tzortziou - Associate Professor, Department of Earth and Atmospheric Sciences, CCNY
  • Tom Legbandt - Senior Laboratory Technician,
  • Nazmi Linia Chowdhury - PhD Candidate,
  • Soe Min Hlaing - PhD Candidate,
  • Amir Ibrahim - PhD Candidate,
  • Ioannis Ioannou - PhD Candidate

Data and Products

Advances in oceanic bio-optical processes are expected to be more heavily focused on improving satellite retrieval products of inherent optical properties (IOPs) of coastal waters, which, because of their complexity, offer more challenges than open ocean waters, where satellite observations and retrieval algorithms are already reasonably effective. Thus, the validation of the current and future Ocean Color satellite data is important for characterizing the optical environment connected with coastal waters, which are of importance because of population concentrations along them and their susceptibility to anthropogenic impacts. To address these concerns and support present and future multi- and hyper-spectral calibration/validation activities, as well as the development of new measurement and retrieval techniques and algorithms for coastal waters, the ORS Lab along with the Naval Research Laboratory at Stennis Space Center, Mississippi, has established a new, scientifically comprehensive, off-shore platform, the Long Island Sound Coastal Observatory (LISCO). This site has been designed to serve as a venue and framework for combining multi- and hyperspectral radiometer measurements with satellite and in situ measurements and radiative transfer simulations of coastal waters, helping to provide more effective closure for the whole measurement validation/simulation loop. Measurements are presented and utilized for multi-spectral calibration/validation of current Ocean Color satellites (MERIS, MODIS, SeaWIFS) in coastal waters, and for evaluating future satellites missions (NPOESS, OCM2, Sentinel-2) with extension to hyperspectral calibration/validations of the hyperspectral sensors (HICO), as well as for improvements in coastal IOP retrieval and atmospheric correction algorithms.

The platform combines an AERONET SeaPRISM radiometer (link to scientific instrumentation) (CIMEL Electronique) as a part of AERONET Ocean Color Network, with a co-located HyperSAS set of radiometers capable of hyperspectral measurements of water-leaving radiance, sky radiance and downwelling irradiance. Both instruments were installed on the Long Island Sound Coastal Observatory (LISCO) in October 2009 and since then have been providing data. SeaPRISM data are transferred by the satellite link to NASA. Raw SeaPRISM data are also collected at the CCNY-ORSL server. HyperSAS data are transmitted via a broadband cellular service as emails to the CCNY-ORSL Sky server. The instruments are positioned on a retractable tower (Floatograph).

In June 2010 the HyperSAS system was upgraded to its polarization version, i.e. HyperSAS POL, which allows the detection of the Stokes components I, Q and U of the upwelling radiance.

Additional in-water measurements:

Field measurements are regularly taken near LISCO for the matchups with the instruments as well to determine variability of water parameters and its impact on the validation of the ocean color satellite data. The instruments currently being deployed are:

  • Absorption and Attenuation Meter + (WET Labs).
  • LISST-100X (Sequoia Scientific,Inc.).
  • Profiler II (Satlantic).
  • Multiangular Hyperspectral Polarimeter.
  • GER 1500 (Spectra Vista Corporation).

References:

  • S. Hlaing, T. Harmel, A. Ibrahim, I. Ioannou, A. Tonizzo, A. Gilerson, and S. Ahmed, "Validation of Ocean Color Satellite Sensors using Coastal Observational Platform in Long Island Sound," Proceedings of SPIE 7825-15. * A. Tonizzo, T. Harmel, A. Ibrahim, S. Hlaing, I. Ioannou, A. Gilerson, J. Chowdhary, B. Gross, F. Moshary and S. Ahmed, "Sensitivity of the above water polarized reflectance to the water composition," Proceedings of SPIE 7825-15.