Satellite instruments operating in the reflective solar wavelength region often require accurate and precise determination of the Bidirectional Reflectance Distribution Function (BRDF) of laboratory-based diffusers used in their pre-flight calibrations and ground-based support of on-orbit remote sensing instruments. The Diffuser Calibration Facility at NASA's Goddard Space Flight Center is a se...

Unlike conventional hydro and tidal barrage installations, water current turbines in open flow can generate power from flowing water with almost zero environmental impact, over a much wider range of sites than those available for conventional tidal power generation. Recent developments in current turbine design are reviewed and some potential advantages of ducted or “diffuser-augmented” current...

Approach to achieve self-calibration three dimensional (3D) light field display is investigated in this paper. The proposed 3D light field display is constructed up on spliced multiLCDs, lens and diaphragm arrays, and directional diffuser. The light field imaging principle, hardware configuration, diffuser characteristic and image reconstruction simulation are described and analyzed, respective...

We consider the errors introduced by speckle pattern statistics of a diffusing target in the measurement of large displacements made with a self-mixing interferometer (SMI), with sub-λ resolution and a range up to meters. As the source on the target side, we assume a diffuser with randomly distributed roughness. Two cases are considered: (i) a developing randomness in z-height profile, with sta...

Long-term calibration monitoring of the bidirectional reflectance distribution function (BRDF) of Spectralon diffusers in the air-ultraviolet is presented. Four Spectralon diffusers were monitored in this study. Three of the diffusers, designated as H1, H2, and H3, were used in the prelaunch radiance calibration of the Solar Backscatter Ultraviolet/2 (SBUV/2) satellite instruments on National O...

In the present work are presented results from numerical simulations performed with the ANSYS-CFX code. It is studied a radial diffuser flow case, which is the main academic problem used to study the flow behavior on flat plate valves. The radial flow inside the diffuser has important behaviors such as the turbulence decay downstream and recirculation regions inside the valve flow channel due t...

turbocharging an engine boosts its power by increasing the amount of input air. this task is accomplished by using the exhaust gas to power a turbine which is engaged with a compressor. the variable geometry turbocharger, vgt is a unique turbocharger that the diffuser vane angle can be changed over a wide range of positions. the mathematics of turbomachinery flow analysis is intensive and uses ...

MODIS Protoflight Model, launched on-board the NASA EOS Terra spacecraft on December 18, 1999, has been in operation for more than two years, providing the science community calibrated data sets for the global studies of the land, oceans, and atmosphere. MODIS has 36 spectral bands, covering the spectral range from 412 to 14200 nm, and provides spatial resolutions of 0.25 km (2 bands), 0.5 km (...

This paper presents a novel Phase Measuring Deflectometry (PMD) method to measure specular objects having discontinuous surfaces. A mathematical model is established to directly relate the absolute phase and depth, instead of the phase and gradient. Based on the model, a hardware measuring system has been set up, which consists of a precise translating stage, a projector, a diffuser and a camer...