Physical Sciences and Mathematics Commons^™

The Time-Dependent Ionospheric Model Using A Tec-Driven Servo: An Investigation Of The Capabilities And Limitations, Jenny Rebecca Whiteley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ionosphere is a region of the atmosphere with a high density of electrons. These electrons affect the behavior of any electromagnetic wave that passes through the ionosphere. Communication and geolocation systems, such as traditional radio and Global Positioning Systems, depend on emitted electromagnetic signals being picked up by a receiver. The presence of the ionosphere affects the behavior of the signal and the quality of the service. Hence, the interactions between electromagnetic waves and the ionosphere provide a major motivation to understand, research, and successfully model and predict the ionosphere and its physical phenomena. This study focused on determining …

Acoustic Waves In The Upper Atmosphere, Geoffrey Blayne Schulthess

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Atmospheric waves can be generated by tropospheric sources such as earthquakes and explosions, causing significant disturbances in the upper atmosphere and ionosphere, where radio wave communications take place. For this analysis, they will be separated into two sub-groups called acoustic waves and gravity waves. Because each of these waves have unique frequency ranges, they can be observed and measured in order to determine their source type and location. Past studies attempted to build the connections between these waves with severe storms and earthquakes, which have improved our understanding of their complexity. Because of the complex nature of these waves, simplified …

Juxtaposition At 45 Km Of Temperatures From Rayleigh-Scatter Lidar And Reanalysis Models, David K. Moser

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Weather and climate forecasts are almost exclusively produced by computer models, which use atmospheric measurements as starting points. It is a well-known and joked-about fact that model predictions can be incorrect at times. One of the reasons this happens is due to gaps in our knowledge of atmospheric conditions in areas where measurements don’t often taken place, such as the mesosphere, which stretches from roughly 45-90 km altitude.

A lidar is a device that can shoot out short bursts of laser light to measure things such as atmospheric thickness at a distance. From this information one can then derive the …

The Application Of Tomographic Reconstruction Techniques To Ill-Conditioned Inverse Problems In Atmospheric Science And Biomedical Imaging, Vern Philip Hart Ii

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tomography is an imaging technique in which 3D models of objects are created from several 2D projections viewed at different angles. When the number of available projections is limited, the resulting data are said to be sparse. This restriction is often a direct result of the imaging geometry used to acquire the data. One-sided views and a small number of receivers can reduce the range of available projections, which makes the object more difficult to reconstruct. Approximate solutions to difficult imaging problems can be obtained using a class of iterative algorithms known as the algebraic reconstruction techniques (ARTs). The presented …

Lidar User’S Manual, Lance William Peterson

Undergraduate Honors Capstone Projects

This is intended to be a user’s manual for the upgraded USU Rayleigh lidar. As such, it begins with a discussion of the purpose of a lidar. This is followed by a brief explanation of the fundamentals of Rayleigh scatter lidar. Next the reasons for and benefits of upgrading the lidar are discussed and as well as how the upgrade was accomplished. After establishing this basis, instructions are provided for operating the lidar, performing basic maintenance, and aligning various components.

A Formula To Express Evapotranspiration As A Function Of Soil Moisture And Evaporative Demands Of The Atmosphere, Aldo L. Norero

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A mathematical expression was developed and tested which describes the relation between evapotranspiration and soil moisture. A general premise of this mathematical model is that the evapotranspiration-soil moisture relationship is determined by interaction of climatic, soil and plant factors. The basic model is

dETa/dYs = -ke[1-(ET_a/ET_mx)]

in which ET_a is the actual evapotranspiration, Ψ_s is the total soil water potential, k is a proportionality coefficient, ∈ is the soil moisture extraction capacity of the atmosphere , and ET_mx is the evapotranspiration that would occur from a particular crop-soil unit when soil moisture was …