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Showing 1 to 20 of 21 for “"Monte Carlo ray trace"”.
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An Application of Wavelet Techniques to Bi-directionality in the Monte Carlo Ray Trace Environment
… of the incorporation of directionality into the Monte Carlo ray-trace (MCRT) environment: (1) the development of a methodology for using directional surface optical data, (2) the measurement of the bi-directional reflectivity functions for two different surfaces, and (3) MCRT simulations …
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Uncertainty and Confidence Intervals of the Monte Carlo Ray-Trace Method in Radiation Heat Transfer
… heat transfer problems solved using the Monte Carlo ray-trace method (MCRT). Four equations are developed to predict the uncertainty of the distribution factor from one surface to another, the global uncertainty of all the distribution factors in an enclosure, the uncertainty of the net …
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A Monte Carlo ray trace tool for predicting contrast in naval scenes including the effects of polarization
… and nighttime conditions by specifying if the ray trace is in the infrared or visible light range. The location of the sun for daytime conditions, and the temperature of the surfaces for nighttime conditions, can all be adjusted by the user. In order to get an accurate estimation of the signal …
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Temperature, pressure, and infrared image survey of an axisymmetric heated exhaust plume
… infrared image invokes the use of an inverse Monte-Carlo ray trace algorithm and an infrared band model for exhaust gases. This dissertation describes an experiment in which the above-mentioned field variables were carefully measured. Results from this experiment, namely tables of measured …
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Advances in Radiation Heat Transfer and Applied Optics, Including Application of Machine Learning
… process and reducing the required resources. The Monte Carlo ray-trace (MCRT) method is the state-of-the-art approach for modeling radiation heat transfer. It has the disadvantage of being a complex and computationally expensive process. In this dissertation, after first identifying the …
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A parametric study of the radiative and optical characteristics of a scanning radiometer for Earth Radiation Budget applications using the Monte-Carlo method
… characteristics of these instruments. The Monte-Carlo ray-trace method has been applied to the ERBE and CERES scanning radiometer instruments to calculate radiation exchange. In a radiative analysis, the surfaces of both instruments are found to emit a significant amount of radiation to the …
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Optical Analysis of a Linear-Array Thermal Radiation Detector for Geostationary Earth Radiation Budget Applications
… detector consists of a thermopile linear array thermal radiation detector. The principal objective of this research is to develop an optical model for the detector and its cavity. The model based on the Monte-Carlo ray-trace (MCRT) method, permits parametric studies to optimize the design of …
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Acceleration techniques for the radiative analysis of general computational fluid dynamics solutions using reverse Monte-Carlo ray tracing
A reverse Monte-Carlo ray trace capable of performing a radiative analysis on arbitrary multiple overlapping structured computational fluid dynamics solution sets is developed. In order to make effective use of time, a method based on a set of simplifying assumptions but using the same calculation …
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Design and analysis of radiometric instruments using high-level numerical models and genetic algorithms
… systems. The modeling environment consists of a Monte Carlo ray-trace (MCRT) model of the optical system coupled to a transient, three-dimensional finite-difference electrothermal model of the detector assembly with an analytic model of the signal-conditioning circuitry. The environment provides …
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Creation and Experimental Validation of a Numerical Model of a Michelson Interferometer
… performance of an optical instrument using the Monte-Carlo ray-trace (MCRT) method has been shown to be an efficient method for transferring knowledge of the coherence state of a beam of light from one instrument to another. The goal of the effort reported here is to create and experimentally …
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A Monte-Carlo-based simulation of jet exhaust nozzle thermal radiative signatures
… The basis of the model is a highly flexible Monte-Carlo ray-trace formulation which is capable of simulating real surface behavior, such as specular reflections, and allows for variation of input parameters such as temperature, surface properties, and geometry. For given input parameters, the …
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Optical and Thermal Radiative Simulation of an Earth Radiation Budget Instrument
… instrument. The numerical model is based on the Monte Carlo Ray-Trace (MCRT) method. The major optical components of the instrument are incorporated into the ray-trace model using 3-D surface equations. A CAD model of the instrument baffle is imported directly into the ray-trace environment using …
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Second-Surface Mirror Effects in Thin-Film Absorber Layers
… heat generation model that is derived using the Monte Carlo ray-trace (MCRT) method. These models are compared by using them to predict the transient temperature response of a generic thermal radiation detector. Results are presented for absorber layers in which the index of refraction is equal …
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Next-Generation Earth Radiation Budget Instrument Concepts
… passing through an aperture for use in the Monte-Carlo ray-trace environment. Described in detail is a deterministic model based upon Heisenberg's uncertainty principle and the particle theory of light. This method is applicable to either Fraunhofer or Fresnel diffraction situations, but is …
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A Numerical Study of the Sensitivity of Cloudy-Scene Bidirectional Reflectivity Distribution Functions to Variations in Cloud Parameters
… field. A shortwave atmospheric radiation Monte-Carlo ray-trace model has been developed as part of this research to predict the earth-reflected radiation field at the top of the atmosphere. This model was developed while paying special attention to clouds including realistic …
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A Radiative Model for the Study of the Feedback Mechanism between Photolytic Aerosols and Solar Radiation
… proposed and improved. Tropospheric ChTMs for trace species are detailed numerical formulations intended to represent the atmospheric system as a whole, accounting for all the individual processes and phenomena that influence climate changes. The development of computer resources and the …
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Development of a Thermal Management Methodology for a Front-End DPS Power Supply
… flow environment. A radiation study using the Monte Carlo ray-trace method for radiation heat transfer resulted in the reduction of some component temperature predictions of significant components. This radiation study focused on an aspect of heat transfer that is often ignored in power …
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Optimization of radiometric channel solar calibration for the Clouds and the Earth's Radiant Energy System (CERES) using the Monte-Carlo method
… attenuate the solar energy. The ERBE MAM is an array of 105 tightly packed concave spherical mirrors with a black mask covering the surface between the hemispherical cavities and partially covering the cavities themselves. In principle, the reflection of solar energy by the MAM was anticipated to …
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Development of a Water Cloud Radiance Model for Use in Training an Artificial Neural Network to Recover Cloud Properties from Sun Photometer Observations
As the planetary climate continues to evolve, it is important to build an accurate long-term climate record. State-of-the-art atmospheric science requires a variety of approaches to the measurement of the atmospheric structure and composition. This thesis supports the possibility of inferring cloud …
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Bidirectional Reflectance Measurements of Low-Reflectivity Optical Coating Z302
… in applications that require control of stray light. Our motivation stems from the use of black coating Lord Aeroglaze® Z302 in aerospace and remote sensing applications and the desire to support the development of bidirectional spectral models that can be used successfully to predict the …
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