The interplay between clouds and aerosols and their contribution to the radiation budget is one of the largest uncertainties of climate change. Most work to date has separated cloudy and cloud-free areas in order to evaluate the individual radiative forcing of aerosols, clouds, and aerosol effects on clouds. Here we examine the size distribution and the optical properties of small, sparse cumul...

Reflectance spectra from 400 to 750 nm were measured in Lake Kinneret, when low phytoplankton stock prevailed, with chlorophyll concentrations from 3.1 to 7.3 pg/l. Algorithms for estimation of chlorophyll (CHL) concentration were devised using reflectances in the blue and green region of the spectrum and natural solar induced fluorescence. The fluorescence was calculated either from the reflec...

Agricultural monitoring using a canopy reflectance model through analyses of hyperspectral and directional CHRIS data is targeted. CHRIS data of the Upper Rhine Valley test-site (Germany) were destriped and geometrically corrected, so that the 5 angular observations can be compared. An atmospherical correction was performed that uses the radiative transfer model MODTRAN 4. An extended version o...

In order to investigate the possibilities of in-situ monitoring of GaAsN bulk layer growth and the crystal quality concerning the formation of misfit dislocations, GaAsN bulk samples with different layer thicknesses were grown using a metal-organic vapor phase epitaxy system equipped with a normal incidence optical reflectance setup. High-resolution X-ray diffractometry and synchrotron radiatio...

We have synthesized ordered carbon nanotube (CNT) arrays in porous anodic alumina (PAA) matrix, and have characterized their total optical reflectance and bi-directional reflectance distribution function after each processing step of the microwave plasma chemical vapor deposition process (MPCVD). For a PAA sample without CNT growth, the reflectance shows an oscillating pattern with wavelength t...

The prediction of spectral water leaving radiance and remote sensing reflectance from a coupled physical/ecological/optical simulation is one of the goals of the ONR Hyperspectral Coastal Ocean Dynamics Experiment (HyCODE). This goal requires coupling a high-resolution circulation model (ROMS) to provide realistic physical forcing to a dynamic ecological model that produces depth-dependent dist...

Most ocean color algorithms are designed for optically deep waters, where the seafloor has little or no effect on remote sensing reflectance. This can lead to inaccurate retrievals of inherent optical properties (IOPs) in optically shallow water environments. Here, we investigate in situ hyperspectral bottom reflectance signatures and their separability for coral reef waters, when observed at t...

Leaf chlorophyll content in coniferous forest canopies, a measure of stand condition, is the target of studies and models linking leaf reflectance and transmittance and canopy hyperspectral reflectance imagery. The viability of estimation of needle chlorophyll content from airborne hyperspectral optical data through inversion of linked leaf level and canopy level radiative transfer models is di...

The sensitive detection and quantitative measurement of biological nanoparticles such as viruses or exosomes is of growing importance in biology and medicine since these structures are implicated in many biological processes and diseases. Interferometric reflectance imaging is a label-free optical biosensing method which can directly detect individual biological nanoparticles when they are immo...

A plasmonic metasurface with an electrically tunable optical response that operates at strikingly low modulation voltages is experimentally demonstrated. The fabricated metasurface shows up to 30% relative change in reflectance in the visible spectral range upon application of 5 mV and 78% absolute change in reflectance upon application of 100 mV of bias. The designed metasurface consists of na...