Document Type

Thesis - Open Access

Award Date

2016

Degree Name

Master of Science (MS)

Department

Electrical Engineering and Computer Science

First Advisor

Larry Leigh

Second Advisor

Dennis Helder

Keywords

Algodones Dunes, BRDF, linear mixed model

Abstract

The primary objective of this project was to develop the Algodones Dunes as a pseudo-invariant calibration site (PICS) suitable for absolute calibration of satellite sensors based on a surface reflectance model. Two approaches were taken during this research: a field campaign and laboratory measurements. The first approach, the field campaign, was accomplished with a trip to the Algodones Dunes from the 8th to the 13th of March, 2015. During the field campaign, several test points from spatially different regions of the Algodones Dunes were studied. Reflectance of the sand at each test point was observed from different view angles. The second approach, laboratory testing, involved bringing several sand samples from different regions of the Algodones Dunes back to SDSU for further analysis. The laboratory setup was built in the SDSU optics laboratory and included the use of a light source, digital power supply, and mechanical arm to study the spectral responses of the sand samples from the field. During the laboratory measurements, the reflectance of each of the sand sample, was observed from different view angles to replicate field measurement techniques. Through both approaches it was found that the reflectance of sand samples from the Algodones Dunes changes quadratically with respect to view zenith angle. To correlate field and laboratory measurements, two solar zenith angles were chosen for laboratory simulation, i.e. 45and 54.4. Since the solar zenith angle varies from 20to 60 over a year in the Algodones Dunes, angles within that range were chosen for the solar zenith angles used in the laboratory measurements. The spectral response of different sand samples were only observed under those two chosen solar zenith angles. Since different equipment was used in the laboratory than in the field, there was some degree of uncertainty due to each of the differing instruments which influenced the data. A Linear Mixed Model was therefore developed in order to incorporate the laboratory uncertainties and predict a more accurate model using the raw data acquired in the laboratory. The data modeled by the Linear Mixed Model approach for different BRDF runs of the same sample, and for different sand samples, were compared to determine whether the spectral response of sand samples from the Algodones Dunes is the same or not. Based on the data modeled by the Linear Mixed Model, it was found that the spectral responses of sand samples brought from the Algodones Dunes are the same. A simple BRDF model was then developed for those angles that are perpendicular to the principal plane of the solar illumination.

Library of Congress Subject Headings

Spectral reflectance -- California -- Algodones Dunes.

Artificial satellites in remote sensing -- Calibration -- California -- Algodones Dunes.

Reflectance -- Measurement.

Description

Includes bibliographical references (pages 105-107)

Format

application/pdf

Number of Pages

125

Publisher

South Dakota State University

Rights

Copyright © 2016 Mahesh Shrestha

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