Development and Evaluation of satellite ValidatiOn Tools by Experimenters

The Polarized Imaging Nephelometer (PI-Neph) is an in situ airborne nephelometer developed at the Laboratory of Aerosols, Clouds, and Optics (LACO) at the University of Maryland Baltimore County (UMBC). PI-Neph measures the ambient scattering coefficient and phase matrix of aerosols to validate satellite aerosol observations. It simultaneously measures at 473 nm, 532 nm, and 671 nm wavelengths, with a scattering angle range of 2 to 178 degrees. PI-Neph typically records measurements every 12 or 36 seconds.

The Langley Aerosol Research Group Experiment (LARGE) is an in situ airborne instrument suite that measures aerosol and cloud microphysical and optical properties, such as size distribution, number concentration, and scattering and absorption coefficients. LARGE includes several instruments, such as the Ultra-High Sensitivity Aerosol Spectrometer (UHSAS), Particle-Into-Liquid Sampler (PILS), Particle Soot Absorption Photometer (PSAP), Cloud and Aerosol Spectrometer (CAS), Cloud Imaging Probe (CIP), and additional cloud and aerosol sensors. The LARGE instruments operate over the 450-700 nm wavelength range, detect particles ranging from 0.003 to 20 μm, and measure at a frequency of 1 Hz. It is primarily used for airborne measurements but can also be deployed on ground-based platforms like vehicles.

The Diode Laser Hygrometer (DLH) is an in situ airborne hygrometer developed by NASA’s Langley Research Center (LaRC). It uses tunable diode laser absorption to detect water vapor in the atmosphere. DLH operates in the near-infrared range at about 1.4 μm and has a measurement frequency of 100 Hz. It can deliver precise measurements of water vapor even when flying through clouds.