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Physical Sciences and Mathematics Commons™
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- Airborne operations (Military science) (1)
- Airdrop (1)
- Atmosphere--Mathematical models (1)
- Atmospheric radiation (1)
- Atmospheric turbulence (1)
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- Attenuation (Physics) (1)
- Cosmic magnetic fields--Mathematical models (1)
- High power lasers (1)
- Infrared equipment (1)
- Laser beams--Atmospheric effects--Mathematical models (1)
- Polarimetric remote sensing (1)
- Radiative transfer (1)
- Refractive index (1)
- Solar energy (1)
- Target acquisition--Mathematical models (1)
- Turbulence (1)
- Winds--Speed--Mathematical models (1)
Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
Determining The Index Of Refraction Of An Unknown Object Using Passive Polarimetric Imagery Degraded By Atmospheric Turbulence, Milo W. Hyde Iv
Determining The Index Of Refraction Of An Unknown Object Using Passive Polarimetric Imagery Degraded By Atmospheric Turbulence, Milo W. Hyde Iv
Theses and Dissertations
In this research, an algorithm is developed to estimate the index of refraction of an unknown object using passive polarimetric images degraded by atmospheric turbulence. The algorithm uses a variant of the maximum-likelihood blind-deconvolution algorithm developed by LeMaster and Cain to recover the true object (i.e., the first Stokes parameter), the degree of linear polarization, and the polarimetric-image point spread functions. Nonlinear least squares is then used to find the value of the complex index of refraction which best fits the theoretical degree of linear polarization, derived using a polarimetric bidirectional reflectance distribution function, to the turbulence-corrected degree of linear …
Realistic Vertical Atmospheric Profiles And Effects From Limited Surface Observations, Dane P. Ranney
Realistic Vertical Atmospheric Profiles And Effects From Limited Surface Observations, Dane P. Ranney
Theses and Dissertations
The ability to accurately describe the atmospheric conditions around us is not only important to the Air Force, but to anyone involved in signal propagation. The programs currently utilized to describe the atmosphere take into account a variety of measures. The LEEDR (Laser Environmental Effects Definition and Reference) program in particular, allows the user to select a location, aerosol and molecular effects model, numerous cloud and precipitation events, as well as other features. Even with the control that the user has, the output that the program provides can vary from actual conditions on a day to day basis. This is …
Passive Ranging Using Infra-Red Atmospheric Attenuation, Douglas J. Macdonald
Passive Ranging Using Infra-Red Atmospheric Attenuation, Douglas J. Macdonald
Theses and Dissertations
Methods of estimating range to an emissive target based on the depth of an atmospheric absorption band are demonstrated. The present work uses measurements of the CO2 absorption band centered at 2.0 µm where signal-to-background ratios are maximum for many applications. Model results, based on high-resolution transmission molecular absorption (HITRAN) database cross sections, are used to predict range accuracy at ranges of up to 50 km and are compared with short range (<5km) experimental results. The spectra of 23 high explosive events were used to validate the model. Using the assumption of a blackbody spectrum, extracted ranges consistently underestimated the true range by approximately 13%. By incorporating the stoichiometry of the fireball from previous research and using particulate contribution as a parameter, the error for the range estimates could be reduced to 3%.
Experimental Validation Techniques For The Heleeos Off-Axis Laser Propagation Model, John D. Haiducek
Experimental Validation Techniques For The Heleeos Off-Axis Laser Propagation Model, John D. Haiducek
Theses and Dissertations
The High Energy Laser End-to-End Operational Simulation (HELEEOS) off-axis scattering algorithm is designed to predict the irradiance that will be detected at a given off-axis location due to atmospheric scattering of a high-energy laser. The HELEEOS system models the propagation of the laser through the atmosphere, accounting for such effects as turbulence, thermal blooming, and atmospheric absorption. The HELEEOS off-axis scattering algorithm uses the scattering phase functions of the Mie scattering models to predict the amount of radiation that will be scattered toward a particular observation location from each point along the beam path, and the total irradiance that will …
Evaluation Of Interplanetary Magnetic Field Tracing Models Using Impulsive Seps, Brian P. Elliott
Evaluation Of Interplanetary Magnetic Field Tracing Models Using Impulsive Seps, Brian P. Elliott
Theses and Dissertations
Current Interplanetary Magnetic Field (IMF) models are evaluated in this study to determine which model(s) perform an accurate representation of this magnetic structure. These IMF models include the Parker Spiral model, the Potential Field Source Surface (PFSS) model, the Wang-Sheeley-Arge (WSA) model and the ENLIL model. Impulsive Solar Energetic Particles (SEPs) are used as tracers to determine the magnetic structure of the IMF and provide source locations for model comparisons. Each individual model is analyzed, compared to the identified solar source region and a longitude/latitude offset of these traces assigned. The model connection of the PFSS and Parker models is …
Application Of Satellite-Derived Wind Profiles To Joint Precision Airdrop System (Jpads) Operations, David C. Meier
Application Of Satellite-Derived Wind Profiles To Joint Precision Airdrop System (Jpads) Operations, David C. Meier
Theses and Dissertations
The Joint Precision Airdrop System has revolutionized military airdrop capability, allowing accurate delivery of equipment and supplies to smaller drop zones, from higher altitudes than was previously possible. This capability depends on accurate wind data which is currently provided by a combination of high-resolution forecast models and GPS dropsondes released in the vicinity of the dropzone shortly before the airdrop. This research develops a windprofiling algorithm to derive the needed wind data from passive IR satellite soundings, eliminating the requirement for a hazardous dropsonde pass near the drop zone, or allowing the dropsonde to be dropped farther from the dropzone. …