NASA’s Coastal and Ocean Airborne Science Testbed (COAST) L. Guild 1 *, J. Dungan 1, M. Edwards 1, P. Russell 1, S. Hooker 2, J. Myers 3, J. Morrow 4, S. Dunagan 1, P. Zell 1, R. Berthold 1, and C. Smith 1 1 NASA Ames Research Center, Moffett Field, CA, USA 2 NASA Goddard Space Flight Center, MD, USA 3 Univ. of Calif., Santa Cruz/NASA Ames, Moffett Field, CA 4 Biospherical Instruments Inc., San Diego, CA, USA

COAST Objectives Develop and integrate the first end-to-end instrument suite for simultaneous measurements of ocean color (modified imaging spectrometer), aerosol optical depth and water vapor column content (sunphotometer), and water bio-optical measurements (microradiometer-based multiwavelength radiometer package) using inputs from an associated precision navigation system. Advance calibration and validation (cal/val) of satellite ocean color through airborne campaigns of the COAST instrument suite flown in conjunction with satellites and in conjunction with in situ ship- based cal/val measurements and moorings. Produce high spatial resolution (5-10 m), atmospherically corrected and geolocated ocean-color products (calibrated to at- sensor radiance) that will advance understanding of coastal freshwater and marine processes and productivity and improve coastal models. Needs: Research capability to address the challenges of remote sensing in the optically complex coastal environment, currently unachievable using satellite resources

Nov 17, 2010 Remote Sensing in the Optically Complex Coastal Zone Airborne remote sensing is used to infer properties of the coastal zone. High spatial resolution is needed to capture high spatial heterogeneity. Airborne reflectance spectra are composites of reflectance from: 1) the atmosphere (particles, gases); 2) the sea surface; 3) the water column (water molecules, phytoplankton, colored dissolved organic matter); and 4) the bottom (sediments, seagrass, corals) COAST Mission Overview

Headwall Ocean Color Imaging Spectrometer Spectrometer: Concentric Pushbroom (Offner-type) Spectral Range: 380 – 760nm*  = 10 nm off-chip binning of 1.5nm pixels) Bands: 40* Spatial Elements: 700 IFOV: 1.23 mrad FOV: 46.7 degrees Weight: 20+ lbs; Power: 30 Watts Array: 1600 x 1200 pixels (7.4  -30C Grating optimized at 450 nm Spectral Smile: <0.25 Pixel (0.625nm) Keystone: <0.9 pixel (6.6  m) Dispersion: 100 nm/mm, linear to <0.5%** * No order-sorting ** Modeled values

Measures: Solar direct-beam transmission, T, at 14 wavelengths,  = nm Data products  Aerosol optical depth (AOD) at 13, nm*  Water vapor column content  Ozone column content**  Aerosol extinction, nm  Water vapor density *+ 3-parameter fit (useful for interpolating) ** Requires low sun, AOD(600 nm)<~ channel Ames Airborne Tracking Sunphotometer (AATS-14)

Monterey Bay Flight Planning Alt = 6000 ft 5 m GSR Alt = 4500 ft 4 m GSR Alt = 12,000 ft 8 m GSR (Max alt w/o O 2 ) Alt = 100 ft (Lowest safe aircraft alt.) (Any speed okay) AATS-14 Microradiometers AATS-14 Headwall AATS-14 Microradiometers Headwall AATS-14 Microradiometers

Monterey Bay Flight Planning Flight line orientation optimized to avoid sunglint

Science Data Plan

Scientific Outcomes 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. Contact: