1. NASA’s Coastal and Ocean Airborne Science Testbed (COAST) L. Guild 1, J. Dungan 1, M. Edwards 1, P. Russell 1, J. Morrow 2, S. Hooker 3, J. Myers 4, R. Kudela 5, S. Dunagan 1, M. Soulage 6, J. Livingston 7, R. Johnson 1, T. Ellis 4, N. Clinton 4, R. Dominguez 4, B. Lobitz 8, K. Martin 1, P. Zell 1, R.Berthold 1, C. Smith 1, K. Vassigh 1, A. Demo 1, W. Gore 1, and J. Torres 9 Abstract The Coastal and Ocean Airborne Science Testbed (COAST) Project is a NASA Earth-science flight mission that will advance coastal ecosystems research by providing a unique airborne payload optimized for remote sensing in the optically complex coastal zone. Teaming NASA Ames scientists and engineers with Biospherical Instruments, Inc. (San Diego) and UC Santa Cruz, the airborne COAST instrument suite combines a customized imaging spectrometer, sunphotometer system, and a new bio-optical radiometer package to obtain ocean/coastal/atmosphere data simultaneously in flight for the first time. The imaging spectrometer (Headwall) is optimized in the blue region of the spectrum to emphasize remote sensing of marine and freshwater ecosystems. Simultaneous measurements supporting empirical atmospheric correction of image data will be accomplished using the Ames Airborne Tracking Sunphotometer (AATS-14). Based on optical detectors called microradiometers, the NASA Ocean Biology and Biogeochemistry Calibration and Validation (cal/val) Office team has deployed advanced commercial off-the-shelf instrumentation that provides in situ measurements of the apparent optical properties at the land/ocean boundary including optically shallow aquatic ecosystems (e.g., lakes, estuaries, coral reefs). A complimentary microradiometer instrument package (Coastal Airborne In-situ Radiometers [C-AIR], Biospherical Instruments, Inc.), optimized for use above water, will be flown for the first time with the airborne instrument suite. Details of the October 2011 COAST airborne mission over Monterey Bay demonstrating this new airborne instrument suite capability will be presented, with associated preliminary data on coastal ocean color products, coincident spatial and temporal data on aerosol optical depth and water vapor column content, as well as derived exact water-leaving radiances. The Mission Science Traceability Matrix Payload Monterey Bay, CA Study Sites Flight Scenario Science Mission October 26-28, 2011 Scientific Outcomes Monterey Bay has both open ocean and optically complex water masses, so the full dynamic range of the sensor suites and protocols being used in the field can be evaluated. The mission consisted of flying the imaging spectrometer, together with the AATS and C-AIR, over an instrumented surface to evaluate the sensor suite. The AATS provides a simultaneous empirical characterization of the atmospheric column (AOD and water vapor) that will be used for atmospheric correction. During flights, we obtained MODIS Aqua and Terra and MERIS data corresponding to contemporaneous deployment of the ship-based measurements from the R/V John Martin (Moss Landing Marine Lab). Satellite observations will be used to compare accuracy of radiance retrievals and derived products versus the Headwall imaging spectrometer, C-AIR, and the in situ measurements. Ship-based Measurements Location (GPS) Water optical data from surface and depth using Satlantic HyperPro II in profiler and “floater” modes –Upwelling radiance (L u ) –Downward irradiance (E d ) –Surface E d (E s ) IOP optics cast using Wetlabs absorption/attenuation meter (ac-s) ASD FieldSpec surface reflectance spectra of water targets Water column profile of density ρ, salinity ‰, and temperature °C (CTD casts) Mapping survey http://geo.arc.nasa.gov/coast/coast_index.html A flight-tested instrument suite suitable for cal/val activities for future satellite missions, as well as currently operating and developing missions. Advanced payload capabilities for airborne carrier platforms including UASs. A multi-sensor ocean/atmosphere data set available for improved atmospheric calibration and in-water algorithms. Methodologies for empirical atmospheric correction developed for future airborne imagers of this type (e.g., NASA PRISM) when they come online. Methods to address the biological properties of important coastal zone ecosystems. Enabling technology for a broad range of research activities in the coastal zone to support the scientific community’s research goals and objectives. Funding: NASA HOPE, Science Mission Directorate, Office of Chief Engineer, and SMD/Earth Science Division 1 NASA Ames Research Center, Moffett Field, CA 94035; 2 Biospherical Instruments Inc., San Diego, CA 92110; 3 NASA Goddard Space Flight Center, MD 20771; 4 Univ. of California, Santa Cruz/NASA, Moffett Field, CA 94035; 5 Univ. of California, Santa Cruz, Santa Cruz, CA, 95064; 6 Universities Space Research Association/NASA Ames Research Center, Moffett Field, CA, 94035; 7 SRI International/NASA Ames Research Center, Moffett Field, CA 94035; 8 Univ. Corporation at Monterey Bay/NASA Ames Research Center, Moffett Field, CA 94035; 9 NASA Postdoctoral Program/NASA Ames Research Center, Moffett Field, CA 94035 Measures: Solar direct-beam transmission (T) at 14 wavelengths, 353-2139 nm Data products:  Aerosol optical depth (AOD) at 13, 353-2139 nm  Water vapor column content [using T(940 nm)]  Aerosol extinction, 340-2139 nm  Water vapor density When A/C flies vertical profiles } Ames Airborne Tracking Sunphotometer (AATS) Preliminary Data C-AIR AATS Imaging Spectrometer Raw data at 555 nm for solar irradiance (E s ), sky radiance (L i ) reaching the sea surface, and total radiance (L t ) above the sea surface. UTC time is +7 hrs from local time. (Left) Aerosol optical depths (AOD) calculated from AATS-14 measurements acquired during Twin-Otter horizontal transects over Monterey Bay on 28 October at altitudes 0.024 km ASL (top left) and 1.877 km ASL (bottom left). The AATS-14 channel center wavelengths (in μm) are given in the legend. (Right) Corresponding mean AOD spectra (symbols) and log(AOD) vs. log(wavelength) quadratic fits (dashed lines) calculated for the total column above the aircraft for the low (blue) and high (red) flight legs, and for the layer (green) bounded by the two altitudes. Coastal Airborne In-situ Radiometers (C-AIR) Vertical profiles of columnar water vapor (left), spectral AOD (middle), and spectral aerosol extinction (right) calculated from AATS-14 measurements acquired during a spiral descent over Monterey Bay on 28 October. Left: False color composite of Headwall imaging spectrometer raw data showing 650 nm (red), 550 (green), and 450 (blue). Pixel resolution is 4 m. Below: Example bloom (red) and open ocean (blue) spectra. Enhanced raw data shows algal bloom in magenta. Next Steps Data processing of C-AIR retrievals to derive exact water-leaving radiance Complete data processing of AATS data calculating AOD and water vapor column content Calibration of Headwall imaging spectrometer data and processing to include atmospheric correction, sun glint suppression, and removal of image vignetting Aknowledgements Naval Postgraduate School Center for Interdisciplinary Remotely Piloted Aircraft Systems (CIRPAS) Twin Otter Team. UC Santa Cruz and Moss Landing RV John Martin field team. UC Davis Spectral Measurements Team: Mui Lay, George Scheer, and Susan Ustin. COAST instruments integration on the CIRPAS Twin Otter platform. Flight path for October 28, 2011. CIRPAS and COAST teams. Flt line 7 Flt line 8Flt line 9Flt line 10