Climate Change: Anticipated Effects on High-Energy Laser Weapon Systems in Maritime Environments

Fiorino, Steven T.; Randall, Robb M.; Bartell, Richard J.; Downs, Adam D.; Chu, Peter C.; Fan, Chenwu

doi:10.1175/2010jamc2482.1

Cited by 6 publications

(4 citation statements)

References 18 publications

(15 reference statements)

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“…Concurrently, there have been numerous advances in tactically relevant HEL modeling, including advances related to wave optics simulation, nonlinear thermal blooming, combined turbulence and thermal blooming effects, and lower atmosphere conditions. [1][2][3][4][5][6][7] However, even at shorter tactical ranges, HEL tracking requirements are very demanding. 8 Yet little published research exists regarding the potential tracking advantages of active (laser) illumination and the resulting detrimental speckle effects at tactical ranges.…”

Section: Introductionmentioning

confidence: 99%

Modeled and measured image-plane polychromatic speckle contrast

2016

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Abstract. The statistical properties of speckle relevant to short-to medium-range (tactical) active tracking involving polychromatic illumination are investigated. A numerical model is developed to allow rapid simulation of speckled images including the speckle contrast reduction effects of illuminator bandwidth, surface slope, and roughness, and the polarization properties of both the source and the reflection. Regarding surface slope (relative orientation of the surface normal and illumination/observation directions), Huntley's theory for speckle contrast, which employs geometrical approximations to decrease computation time, is modified to increase accuracy by incorporation of a geometrical correction factor and better treatment of roughness and polarization. The resulting model shows excellent agreement with more exact theory over a wide range. An experiment is conducted to validate both the numerical model developed here and existing theory. A diode laser source with coherence length of 259 AE 7 μm is reflected off of a silver-coated diffuse surface. Speckle data are gathered for 16 surface slope angles corresponding to speckle contrast between about 0.55 and 1. Taking the measured data as truth, both equations show error mean and standard deviation of less than 3%. Thus, the theory is validated over the range of this experiment.

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Section: Introductionmentioning

confidence: 99%

Modeled and measured image-plane polychromatic speckle contrast

2016

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“…Atmospheric conditions influencing propagation of electromagnetic waves in the optical domain vary regionally as has been shown by [31]. For determining hazards from atmospheric scattering and propagation effects, localized models for aerosols and turbulence conditions are required.…”

Section: Further Studies Requirements and Possible Solutionsmentioning

confidence: 99%

Quantitative laser safety analysis for application of high-energy lasers in a field test

Böker

Schwarz-Hemmert

Netzler

2014

Laser Technology for Defense and Security X

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There is a variety of national and international standards for laser safety analysis requesting for risk reduction of hazards due to laser radiation. A lot of risks are already addressed by the standards. Thus appropriate evaluation methods for calculating dangerous radiation levels and measures for risk reduction are available for certain types of risks. However, when high energy lasers are applied in outdoor environments a variety of additional risks may arise. Due to high laser energy and varying outdoor environmental conditions, appearance and options of risks increase. Assuming that radiation can be held below certain Maximum Permissible Exposure (MPE) levels anywhere in the unmonitored surrounding is impracticable when high energy lasers (HEL) are applied in outdoor environments. Therefore, an adjusted approach of methodology and appropriate materials, i.e. data and algorithms for risk assessment, is necessary.In the study reported here, we conduct a probabilistic risk assessment (PRA) focused on an application of HEL radiation in outdoor field tests. Thus we identify hazards within a particular field test environment and estimate the risks associated to these hazards using a probabilistic approach. The risks are assessed for being acceptable by probability of occurrence and severity. General risk management processes then demand that risks that exceed an acceptable level need to be reduced through appropriate risk reduction measure that either reduce the probability of occurrence or the consequences of an accident associated to that hazard. After having verified that all our recommended measures are implemented to a sufficient extend, field tests may be conducted.

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“…The maximum grid point was given a transparency value of 1, meaning it was completely opaque, and the minimum which in all cases was zero was given a transparency value of zero, making it completely transparent. 6 The global sodium layer monthly plots can be found in Appendix II. Looking at the plots there are apparent features within the monthly plots.…”

Section: Global Sodium Data Viewed In Leedrmentioning

confidence: 99%

“…Results from this will be discussed in this paper. 6 Incorporating the sodium layer concentration data added to LEEDR, makes it additionally available to the High Energy Laser End-to-End Operational Simulation (HELEEOS) toolset. New functionality was added LEEDR and HELEEOS so that a sodium guidestar can be simulated.…”

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confidence: 99%

World wide study of the performance of a sodium guidestar

Zuraski

Fiorino²

2014

SPIE Proceedings

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This study quantifies the feasibility for a mobile sodium guidestar system. Simulations are run using the High Energy Laser End-to-End Operational Simulation (HELEEOS) software package with global sodium layer climatology data. Sodium layer data used was collected from the Optical Spectrograph and Infrared Imaging System (OSIRIS) sensor package on board the Odin satellite from 2005 through 2011 and provides a detailed global representation of the variable sodium layer occurring at an altitude of approximately 90 km in the atmosphere. This data is used in conjunction with the HELEEOS atmospheric propagation modeling to create realistic sodium guidestar models. The atmospheric effects for the laser propagation scattering model and creation of the sodium guidestar are defined in the worldwide probabilistic climatic database available in the HELEEOS software package. The simulations run evaluated the performance of a guidestar as viewed from along the propagation path and from nonpropagation path viewing angles for engagement scenarios in various locations on earth. HELEEOS includes a fast-calculating, first principles, worldwide surface to 100 km, with extensions above 100 km to account for the sodium layer, atmospheric propagation and characterization package. This package enables the creation of profiles of temperature, v pressure, water vapor content, optical turbulence, atmospheric particulates and hydrometeors as they relate to line-by-line layer transmission, path and background radiance at wavelengths from the ultraviolet to radio frequencies. HELEEOS is able to produce realistic evaluations of laser propagation, imaging, and adaptive optics systems by use of an end to end directed energy propagation model that incorporates probabilistic, climatological data from temporally and spatially variable meteorological, aerosol, and turbulence profiles. Specifically, HELEEOS performs its propagation calculations utilizing the following algorithms, models and datasets: the Scaling for HEL and Relay Systems (SHaRE) scaling law algorithms, High Resolution Transmission (HITRAN) database for molecular absorption, Global Aerosol Dataset (GADS), Advanced Navy Aerosol Model (ANAM), the Adaptive Optical Compensation of Thermal Blooming (AOTB) model, various turbulence models, and other physics based atmospheric propagation algorithms. HELEEOS was developed by the United States Air Force Institute of Technology (AFIT) under the sponsorship of the High Energy Laser Joint Technology Office. vi Dedicated to my parents vii ACKNOWLEDGEMENTS My special thanks are in order to Dr. Steven T. Fiorino, my advisor, for providing the time and software necessary for the work contained herein, and for directing this thesis and bringing it to its conclusion with patience and expertise. I would also like to express my appreciation to everyone who has helped me with this work. This includes Brannon Elmore, who provided updates to the software used for this thesis and Erin Dawkins, who facilitated the transfer of sodium layer data from the Unive...

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Climate Change: Anticipated Effects on High-Energy Laser Weapon Systems in Maritime Environments

Cited by 6 publications

References 18 publications

Modeled and measured image-plane polychromatic speckle contrast

Modeled and measured image-plane polychromatic speckle contrast

Quantitative laser safety analysis for application of high-energy lasers in a field test

World wide study of the performance of a sodium guidestar

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