Development and Evaluation of satellite ValidatiOn Tools by Experimenters

The Polarized Imaging Nephelometer (PI-Neph) is an in situ airborne nephelometer designed and built 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 observations of aerosols. It measures simultaneously across the 473 nm, 532 nm, and 671 nm wavelengths and at a scattering angle range of 2 to 178 degrees. PI-Neph has a typical measurement frequency of 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 coefficient. LARGE consists of multiple instruments including 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 across the 450-700 nm wavelength range, can detect particles in the size range between 0.003-20μm, and have a measurement frequency of 1 Hz. It is typically used for airborne measurements, but it also can be deployed on ground-based platforms such as 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 measure water vapor in the atmosphere. DLH operates in the near-infrared region at around 1.4 μm and has a measurement frequency of 100 Hz. It can provide accurate measurements of water vapor even while flying through clouds.