SBIR-STTR Award

Visidyne proposes to demonstrate the utility of visible and IR sensors for detecting and characterizing bright targets through cloud layers. Visidyne proposes to take advantage of sensors routinely operated as part of the Department of Energy's Atmospheric Radiation Measurement (ARM) program at their Clouds and Radiation Testbed (CART) in Oklahoma. An uplooking geometry, viewing the sun through clouds from these ground based sensors, will serve as a surrogate for the downlooking geometry of an overhead sensor viewing a terrestrial target such as a missile plume. The Cimel sunphotometer, a robotic, scanning photometer normally used to investigate atmospheric aerosols, will serve as the primary visible and IR sensor. (The proposed use of this instrument should not be confused its new "cloud mode" that is used to infer a broad-area or average cloud optical depth.) The proposed use will provide a cost-effective method for demonstrating potential capabilities of space-based surveillance sensors and validating theory and computer simulations In Phase I Visidyne will use cloud analyses, e.g., time series of cloud cover fraction and depth, routinely generated at the CART site to select specific datasets to analyze. Visidyne will download the selected databases and then perform comparisons with its Monte Carlo Adjoint Problem (MCAP) reverse scattering code and also with coincident analyses from satellite datasets, e.g., the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra and Aqua satellites

In Phase 1 Visidyne demonstrated the utility of its breadboard, ground-based, Sun and Aureole Measurement (SAMNET) sensor coupled with its state-of-the-science models for particle scattering for measuring and deriving the transmission and scattering properties of clouds. Knowledge of these properties is critical to the correct interpretation of missile launch signals viewed through clouds by space-based, electro-optical sensors. In Phase 2 Visidyne proposes further applications of its SAMNET instruments and analysis software to develop the approach and algorithms as they relate to MDA operational mission requirements for early launch detection through clouds. Visidyne proposes to (1) collect statistics on field test-site measurements of cloud scattering properties, including parameters to correct overhead observations of signals transmitted through clouds, (2) analyze the variability of the measurements of cloud scattering properties affecting overhead observations, and (3) collect data to test approaches for coupling SAMNET measurements with meteorological satellite observations to provide propagated (interpolated) solutions for operational use in areas of interest (AOIs).

Keywords:
Early Launch Detection, Clouds, Infrared, Aureole,