Suppressing specular electromagnetic wave reflection or backward radar cross section is important and of broad interests in practical electromagnetic engineering. Here, we present a scheme to achieve broadband backward scattering reduction through diffuse terahertz wave reflection by a flexible metasurface. The diffuse scattering of terahertz wave is caused by the randomized reflection phase di...

The first successful deployment of the fullyoperational ultraviolet rotating shadow-band spectroradiometer occurred during the May 2003 US Department of Energy’s Atmospheric Radiation Measurement program’s Aerosol Intensive Observation Period. The aerosol properties in the visible range were characterized using redundant measurements with several instruments to determine the column aerosol opti...

1 The reflectance of light from the surface of an object is modelled by a new technique, using components extracted from a set of 64 images taken in an illumination dome, Techniques of photometric stereo are used to determine albedo and surface normals at each pixel. The ratio of actual to diffuse reflectance is modelled to find the specular angle and an angular distribution of intensity based ...

In this paper, we present new range acquisition and 3D reconstruction methods that are capable of modeling specular objects. Multipeak range imaging, a new concept in range data collection that accounts for the effects of interreflections, is used to acquire range data of an object. False measurements caused by interreflections are then iteratively eliminated by using constraints based on local...

In this paper, we propose a method to measure specular objects regardless occlusion. The main contribution of this paper is that we have shown that the scattering of incident and specular reflection enable us to measure occluded surfaces. We locate objects in a tank filled with participating media, irradiate a laser beam to the objects, and observe the scattering of incident light and specular ...

Diffusion theory and similarity relations were used to calculate the optical diffuse reflectance of an infinitely narrow laser beam incident upon a semi-infinite turbid medium. The results were analyzed by comparison with the accurate results from Monte Carlo simulations. Because a large number of photon packets were traced, the variance of the results from Monte Carlo simulations was small eno...

The carriers of diffuse interstellar bands are still mysterious species. There exist many arguments that diffuse bands at 5797 and 5850 angstroms have the same carrier. Using high-resolution spectra of few dozens of reddened stars we have searched mutual correlation between intensities of considered bands. Results of our analysis indicate that 5797 and 5850 really tend to have the same carrier.

As an independent check on previous measurements of the isotopic abundance of oxygen through the Galaxy, we present a detailed analysis of the ground state rotational lines of 16 OH and 18 OH in absorption towards the giant molecular cloud complex, Sagittarius B2. We have modelled the line shapes to separate the contribution of several galactic clouds along the line of sight and calculate 16 OH...