scholarly journals The effect of molding conditions on the quality of geopolymer surfaces

2020 ◽  
Vol 50 (1) ◽  
Author(s):  
Janusz Jaglarz ◽  
Dominik Wyszyński ◽  
Michał Lach ◽  
Janusz Mikuła ◽  
Ryszard Duraj
Keyword(s):  
Point Of View ◽  
Contact Method ◽  
Bidirectional Reflectance Distribution Function ◽  
Qualitative Properties ◽  
Large Area ◽  
Bidirectional Reflectance ◽  
Measuring Surface ◽  
Measurement And Analysis ◽  
Bidirectional Reflectance Distribution

The presented work describes the method of measuring surface topography with application of BRDF (bidirectional reflectance distribution function), ellipsometry and spectrophotometry. This non-contact method enables measurement and analysis of large area surfaces, such as plasters and facades. A standard method of topography analysis does not describe sufficiently all of the interesting features. The visual aspect of the surface evaluation is very important from the functional and utilitarian point of view. The proposed methods of surface analysis enable not only the quantitative evaluation but also indirectly the qualitative properties (visual aspects).

scholarly journals A Hyperspectral Bidirectional Reflectance Model for Land Surface

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4456
Author(s):  
Qiguang Yang ◽  
Xu Liu ◽  
Wan Wu
Keyword(s):  
Land Surface ◽  
Solar Observation ◽  
Bidirectional Reflectance Distribution Function ◽  
Satellite Measurements ◽  
Bidirectional Reflectance ◽  
Reflective Spectrum ◽  
Vegetation Database ◽  
Airborne Sensors ◽  
Bidirectional Reflectance Distribution

A hyperspectral bidirectional reflectance (HSBR) model for land surface has been developed in this work. The HSBR model includes a very diverse land surface bidirectional reflectance distribution function (BRDF) database with ~40,000 spectra. The BRDF database is saved as Ross-Li parameters, which can generate hyperspectral reflectance spectra at different sensor and solar observation geometries. The HSBR model also provides an improved method for generating hyperspectral surface reflectance using multiband satellite measurements. It is shown that the land surface reflective spectrum can be easily simulated using BRDF parameters or reflectance at few preselected wavelengths. The HSBR model is validated using the U.S. Geological Survey (USGS) vegetation database and the AVIRIS reflectance product. The simulated reflective spectra fit the measurements very well with standard deviations normally smaller than 0.01 in the unit of reflectivity. The HSBR model could be used to significantly improve the quality of the reflectance products of satellite and airborne sensors. It also plays important role for intercalibration among space-based instruments and other land surface related applications.

scholarly journals One-shot BRDF imaging system to obtain surface properties

2021 ◽  
Author(s):  
Hiroshi Ohno ◽  
Takahiro Kamikawa
Keyword(s):  
Surface Properties ◽  
Imaging System ◽  
Reconstruction Method ◽  
Surface Reflectance ◽  
Bidirectional Reflectance Distribution Function ◽  
Bidirectional Reflectance ◽  
Color Mapping ◽  
System A ◽  
Cone Surface ◽  
Bidirectional Reflectance Distribution

AbstractThe bidirectional reflectance distribution function (BRDF) that describes an angle-resolved distribution of surface reflectance is available for characterizing surface properties of a material. A one-shot BRDF imaging system can capture an in-plane color mapping of light direction extracted from a surface BRDF distribution. A surface roughness identification method is then proposed here using the imaging system. A difference between surface properties of a matt paper and a glossy paper is experimentally shown to be detected using the method. A surface reconstruction method of an axisymmetric micro-object using the imaging system is also proposed here. The imaging system experimentally shows that it can reconstruct an axisymmetric aluminium cone surface with a height of 37 μm.

Comparison of Experiment With Monte Carlo Simulations on a Reflective Gap Using a Detailed Surface Properties Model

1996 ◽  
Vol 118 (2) ◽  
pp. 388-393 ◽  
Author(s):  
J. Zaworski ◽  
J. R. Welty ◽  
B. J. Palmer ◽  
M. K. Drost
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Grazing Angle ◽  
Incident Radiation ◽  
Monte Carlo Code ◽  
Bidirectional Reflectance Distribution Function ◽  
Bidirectional Reflectance ◽  
Detailed Surface ◽  
Bidirectional Reflectance Distribution

The spatial distribution of light through a rectangular gap bounded by highly reflective, diffuse surfaces was measured and compared with the results of Monte Carlo simulations. Incorporating radiant properties for real surfaces into a Monte Carlo code was seen to be a significant problem; a number of techniques for accomplishing this are discussed. Independent results are reported for measured values of the bidirectional reflectance distribution function over incident polar angles from 0 to 90 deg for a semidiffuse surface treatment (Krylon™ flat white spray paint). The inclusion of this information into a Monte Carlo simulation yielded various levels of agreement with experimental results. The poorest agreement occurred when the incident radiation was at a grazing angle with respect to the surface and the reflectance was nearly specular.

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