| System-Wide Water Resources Program Nutrient Sub-Model (SWWRP-NSM) Version 1.1 |
01-Sep-2008 |
55 pages |
| Authors:
Zhonglong Zhang; Billy E Johnson; Terry K Gerald; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS ENVIRONMENTAL LAB
|
 | This report discusses major developments that have occurred since the release of NSM Version 1.0. These improvements were in the areas of: 1) partitioning of nutrients (dissolved and adsorbed) within surface runoff, 2) mass transfer of nutrients between the soils and overlying water column, 3) erosion and sedimentation of particulate nutrients, and 4) soil plant dynamics. Nutrients at or near the soil surface can be transformed to overland flow in ... |
|
| Assessment of Superstructural Ice Protection as Applied to Offshore Oil Operations Safety |
01-Sep-2008 |
155 pages |
| Authors:
Charles C Ryerson; ENGINEER RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB
|
| Superstructure sea spray icing and atmospheric icing from snow, freezing rain, freezing drizzle, rime, sleet, and frost reduce the safety of offshore platform and supply boat operations. Though icing reduces safety and reduces operational efficiency, it has not caused the loss of offshore platforms. Supply boats are at greater risk of loss from icing than are platforms. Platforms operating in cold regions are protected primarily by designs that reduce ice ... |
|
| Ring-Wave Measurements from Natural Rain |
Sep-2003 |
4 pages |
| Authors:
L F Bliven; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WALLOPS ISLAND VA WALLOPS FLIGHT CENTER
|
| The authors present preliminary results of their efforts to measure ring-waves generated by natural rain. Winds at sea are monitored by remote sensing of radars observing sea surface roughness. Yet rain also roughens the sea surface. Improved understanding of sea-surface roughness during rain contributes to better measurements of winds and rain at sea. The data presented in this paper demonstrate that the authors have successfully adopted laboratory equipment and developed ... |
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| Recognition of Retroreflective Road Signs During Night Driving |
14 MAY 2003 |
|
| Authors:
J. Berzinsh; M. Ozolinsh; P. Cikmac; K. Pesudovs; LATVIA UNIV RIGA DEPT OF OPTOMETRY ANDVISION SCIENCE
|
 | Temporal waveforms of the illumination at the driver eyes position were determined in various night traffic and weather conditions (ideal weather and correct aligned lights as compared with dirty lamps and raindrops on the windscreen). The statistics of retinal illumination were analyzed and a computer controlled technique was developed to simulate similar changes of eye illumination. The participant fixated on retroreflective optical stimuli at a distance of 5 m. The ... |
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| Simulating Wet Deposition of Radiocesium from the Chernobyl Accident |
MAR 2001 |
124 pages |
| Authors:
Aaron M. Kinser; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| In response to the Chernobyl nuclear power plant accident of 1986, a cesium-137 deposition dataset was assembled. Most of the airborne Chernobyl cesium was wet deposited, either via interception by falling raindrops or via absorption into cloud droplets destined to become raindrops. The Hybrid Single- Particle Lagrangian rated Transport (HYSPLIT) model, developed at Air Resources Laboratory, is used to simulate the transport and deposition of Chernobyl cesium-137. A cloud base ... |
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| Scavenging Models for Smokes |
FEB 2001 |
20 pages |
| Authors:
Steven M. Kovel; ARMY RESEARCH LAB ADELPHI MD COMPUTATIONAL AND INFORMATION SCIENCES DIRECTORATE
|
| The smoke and obscuration computer model known as the Combined Obscuration Model for Battlefield Induced Contaminants (COMBIC) has the potential for treating the effect of precipitation scavenging as one of the model's input parameters. This report examines the impact of rainfall on the evolution of a white phosphorous (WP) smoke cloud based upon the predictions of the model. The result of the analysis indicates that the effect of precipitation scavenging ... |
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| Performance of Imaging Laser Radar in Rain and Fog |
MAR 1998 |
113 pages |
| Authors:
Kathleen M. Campbell; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
|
| The Air Force is currently developing imaging laser radar systems (ladar) for use on precision guided munitions and other imaging systems. Scientists at Eglin Air Force Base, in conjunction with Wright Laboratories, are testing a 1.06-um wavelength ladar system and need to understand the weather effects on the ladar images. As the laser beam propagates through the atmosphere, fog droplets and raindrops can cause image ... |
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| Advanced Rotor Blade Erosion Protection System |
JUL 96 |
293 pages |
| Authors:
William D. Weigel; KAMAN AEROSPACE CORP BLOOMFIELD CT
|
| Two new hydrolysis-free elastomeric materials have been identified, tested and fabricated into full length leading edge erosion guards. The were applied to K747 composite main rotor blades for operational flight evaluation on the AH-1 Cobra helicopter. One exhibits more than four times the rain resistance and twice the sand resistance as the current material. The other has six times the sand resistance and equivalent rain resistance. A worldwide survey was ... |
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| Representative Values of Icing-Related Variables Aloft in Freezing Rain and Freezing Drizzle |
MAR 96 |
54 pages |
| Authors:
Richard K. Jeck; FEDERAL AVIATION ADMINISTRATION TECHNICAL CENTER ATLANTIC CITY NJ
|
| Radiosonde and surface observations in freezing rain (ZR) and freezing drizzle (ZL), and a limited number of aircraft measurements in ZR, have been examined for information on the magnitude and altitude dependence of meteorological variables associated with aircraft icing in these conditions. The variables include temperature aloft, humidity (clouds), and windshear from the radiosondes; surface temperatures, ceiling heights, precipitation type and amount from the surface observations; and temperature, dropsize, rainwater ... |
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| Soil Freeze-Thaw Effects on Bank Erodibility and Stability |
SEP 95 |
23 pages |
| Authors:
Lawrence W. Gatto; COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
|
| When air temperature is below ground temperature, a thermal gradient is established in the soil that causes the soil to lose heat to the atmosphere. When the soil has lost sufficient heat for soil water to freeze, the newly formed ice changes soil structure by disaggregating, separating, and reorienting soil particles. The suction set up within the freezing soil draws water to the freezing zone through the film of unfrozen ... |
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| Studies of Rain Erosion Mechanisms in a Range of IR Transmitting Ceramics - Including Coated Samples |
JAN 94 |
246 pages |
| Authors:
J. E. Field; C. R. Seward; C. S. Pickles; E. J. Coad; M. Watt; CAMBRIDGE UNIV (UNITED KINGDOM) CAVENDISH LAB
|
| This report starts by reviewing what is known about the rainfield an aircraft or missile flies through. It then looks at some of the methods available to simulate it. Although not a perfect reproduction of a high velocity raindrop impact, the waterjet techniques, developed in the Cavendish Laboratory, Cambridge, are found to be close enough simulations of the real environment to be useful research tools. A standard method of operation ... |
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| The Appearance of the Sun and Moon Seen Through Clouds |
DEC 93 |
66 pages |
| Authors:
Jeffrey R. Linskens; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| The sun occasionally appears fuzzy through altostratus because altostratus is composed of larger particles than other clouds, and is of the necessary optical thickness. Experimental results indicate that the range of optical thicknesses of a cloud at which a fuzzy sun is seen increases with the size of the particles. This relationship is caused by an increase in the attenuation of contrast at high spatial frequencies relative to that at ... |
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| Aircraft Corrosion Study |
DEC 93 |
62 pages |
| Authors:
J. T. Stropki; R. D. Smith; BATTELLE COLUMBUS DIV OH
|
| A comparison of the test results obtained for the unaged French and 2024-T3 (bare and hard anodized) alloys suggests that the resistance of all materials to raindrop erosion is identical. Superior performance of the hard anodized Alloy 2024-T3 sample was not observed during the erosion testing. Post- test examinations of the hard anodized 2024-T3 sample indicate that the performance of the coating was limited by spalling of the coating from ... |
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| The Initiation of Lightning and the Growth of Electric Fields in Thunderstorms |
DEC 93 |
60 pages |
| Authors:
John Latham; UNIVERSITY OF MANCHESTER INST OF SCIENCE AND TECHNOLOGY (UNITED KINGDOM) DEP T OF PHYSICS
|
| Further research into the glaciation of convective clouds of-the type that produce lightning has revealed that the early stages of ice formation can be detected by measurement of the supercooled droplet radius - a result which also has climatological implications. Further laboratory experiments have shown that the most effective methods of lightning initiation are likely to involve supercooled raindrops, with threshold fields around 300kV/m. A new model of thundercloud electrification ... |
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| Mechanisms of Bubble-Related Oceanic Ambien Noise |
14 APR 93 |
25 pages |
| Authors:
Andrea Prosperetti; JOHNS HOPKINS UNIV COCKEYSVILLE MD BALLISTIC ANALYSIS LAB
|
| The report contains a list of papers completed in the course of the project and a copy of the first page of each, which includes the abstract. The main achievements of the activity carried out under this grant have been an understanding of the mechanism of rain noise and of the role of bubble clouds in ambient noise generation at low frequencies. The first problem has been investigated theoretically in ... |
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| Birds Mimicking Microbursts on June 2, 1990 in Orlando, Florida |
10 JUL 92 |
|
| Authors:
M. A. Isaminger; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
|
| During 1990 and 1991, the Terminal Doppler Weather Radar (TDWR) testbed collected Doppler radar measurements in Orlando, Florida in support of the TDWR Project. The main focus of the project is to develope algorithms that automatically detect wind shears such as microbursts anti gust fronts. While the primary goal of the TDWR is to detect scattering from raindrops, the sensitivity of the system allows for the detection of biological echoes ... |
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| Oscillating Microbubbles Created by Water Drops Falling on Fresh and Salt Water: Amplitude, Damping and the Effects of Temperature and Salinity |
JUN 92 |
73 pages |
| Authors:
Christopher D. Scofield; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Recent studies of underwater sound produced by raindrops have identified trapped bubbles as the principle sound source. Two mechanisms have been described, one for small drops (Type I) ad one for large drops (type II). A study of sound produced by large raindrops (Jacobus,l99l) showed that the underwater sound radiated by raindrops is 45% less in salt water (salinity, 35ppt) than in fresh water. The same studies also showed that ... |
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| Underwater Sound Radiation from Large Raindrops |
SEP 91 |
86 pages |
| Authors:
Peter W. Jacobus; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The principal underwater sound energy radiated by terminal velocity raindrops at sea is due to micro-bubble entrainment and oscillations which occur for drops of the two diameter ranges 0.8 to 1.1 mm (Type I) and 2.2 to 4.6 mm (Type II). In the absence of bubbles, particularly between 1.1 and 2.2 mm, the impact sound radiation is significant. The Type I bubbles radiate at frequencies close to 15 kHz, whereas ... |
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| Ambient Sound in the Ocean Induced by Heavy Precipitation and the Subsequent Predictability of Rainfall Rate |
JUN 91 |
78 pages |
| Authors:
Charles C. McGlothin Jr; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| An experiment was preformed in the Gulf Mexico to characterize the underwater sound generated by the heavy precipitation and to determine if rainfall rate can be measured using underwater sound. During this stage of the experiment, twenty-two data sets were recorded with rainfall rates up to 340 mm/ hr. For a given rainfall rate, it is found that sound levels from heavy convective precipitation are higher at the beginning of ... |
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| Characteristics of Sound Radiation from Large Raindrops |
DEC 90 |
52 pages |
| Authors:
David E. Snyder; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Drop diameters from 2.7 mm to 4.6 mm are common in heavy rainfall. The impact and bubble signals of the underwater sound radiation from these large drops at their terminal velocities have been identified. At a 1 MHz sampling rate, several notches are observed in the approximately 100 microns per second duration impact signal. These notches with time separations of 3 to 4 microns per second between peak and trough, ... |
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| A Characterization of Underwater Sound Produced by Heavy Precipitation |
DEC 90 |
70 pages |
| Authors:
Chih-Lung Tan; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| An experiment by the Naval Postgraduate School and the National Data Buoy Center was performed in the Gulf of Mexico to investigate the underwater sound generated by heavy precipitation under a variety of conditions. During the first stage of the experiment, nine data sets were obtained with rainfall rates up to 300 mm/hr. The characteristic fifteen kilohertz peak in the underwater sound spectrum generated by small raindrops in light rain ... |
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| Backscattering by Nonspherical Particles, Using the Coupled-Dipole Method: An Application in Radar Meteorology |
DEC 90 |
|
| Authors:
Clifton E. Dungey; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| In the coupled-dipole method, an arbitrary particle is modeled as an array of N polarizable subunits each of which gives rise to only electric dipole radiation. Of all scattering angles, backscattering is the most sensitive to small changes in particle size and shape. The coupled-dipole method's ability and limitations for calculating backscattering are demonstrated. For particles with size parameter less than that associated with the first backscattering minimum, the coupled-dipole ... |
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| Polarisation Radar Studies of Precipitation: Implementation of the Technique and Data Interpretation |
25 JUL 90 |
|
| Authors:
Anthony J. Illingworth; UNIVERSITY OF MANCHESTER INST OF SCIENCE AND TECHNOLOGY (UNITED KINGDOM) DEP T OF PHYSICS
|
| Polarization radar observations provide information on characteristics of precipitation particles not available with conventional weather radar. Observations are reported for four parameters made with the 25m Chilbolton dish the largest steerable meteorological radar in the world. These are the first S-band measurements of the linear depolarisation ratio and the most accurate co- copolar correlations yet reported. Ten publications describe the work in more detail. This report demonstrates how the new ... |
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| Modeling a Rain-Induced Mixed Layer |
JUN 90 |
|
| Authors:
Hong B. Hur; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| With the development of ocean surface remote sensing, air sea interaction theory and the theory of underwater sound generation at the ocean surface, the potential calming effect on surface gravity waves by raindrop induced mixing has become important. The rain induced mixed layer was studied with models based on the turbulent kinetic energy budget. A bulk mixed layer model was tuned with laboratory experimental data. The turbulent kinetic energy going ... |
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| Observation of Stratiform Rain with 94 GHz and Ka-Band Radars |
23 MAY 90 |
|
| Authors:
Roger Lhermitte; ROSENSTIEL SCHOOL OF MARINE AND ATMOSPHERIC SCIENCE MIAMI FL DIV OF METEOROLO GY & PHYS OCEANOGRAPHY
|
| The project is concerned with observations of stratiform rain at vertical incidence conducted with a 3-mm wavelength Doppler radar and their analysis and interpretation. The data interpretation is dominated by the need to involve Mie scattering functions which exhibit deep oscillations in the raindrop size range. These considerations lead to a method of separating the contributions of raindrops' terminal velocity and air velocity in Doppler spectra obtained from observation of ... |
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| Sources of Ambient Noise in the Ocean: An Experimental Investigation |
12 MAY 89 |
|
| Authors:
Hugh C. Pumphrey; Lawrence A. Crum; NATIONAL CENTER FOR PHYSICAL ACOUSTICS UNIVERSITY MS
|
| The general characteristics of underwater sound produced at the ocean surface have been known for many years and recent measurements have also described the sound of rainfall. The mechanisms which produce these sounds have remained a mystery. This report describes a series of laboratory experiments in which various simple mechanisms in the 0.5-100 kHz frequency range were examined. A large part of the work describes the sounds made by the ... |
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| A Study of the Identification and Development of Precipitation Using Dual Polarization Radar |
20 JAN 88 |
|
| Authors:
Anthony J. Illingworth; UNIVERSITY OF MANCHESTER INST OF SCIENCE AND TECHNOLOGY (ENGLAND) DEPT OF PUR E AND APPLIED PHYSICS
|
| This final report describes work performed with the Chilbolton dual polarization radar under contract number AFOSR-86-0193. In addition to measuring the conventional radar reflectivity factor, Z, this radar can measure the differential reflectivity, ZDR, which senses the shape of the precipitation particles. ZDR may be used to differentiate water from ice, to measure the mean size of raindrops and to provide more accurate estimates of rainfall rates. This report is ... |
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| On the Theory of Electromagnetic Scattering from a Raindrop Splash |
31 DEC 87 |
|
| Authors:
Lewis B. Wetzel; NAVAL RESEARCH LAB WASHINGTON DC
|
| Electromagnetic scattering from a raindrop splash on a water surface is examined in terms of the splash structures that have been disclosed by high- speed photography. Of the three basic scattering features, the crown, the stalk, and the ring wave, the first two are modeled as dielectric cylinders, while the third is treated by a perturbation approximation. Cross section predictions based on these models are found to be in good ... |
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| Thunderstorm Influence on Boundary Layer Winds |
DEC 86 |
|
| Authors:
Jill M. Schmidt; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| The objective of this thesis was to develop a conceptual model of selected pre-storm ambient conditions as a function of the strength of a thunderstorm's outflow. The time of maximum rainfall in relation to the time of maximum outflow was a thunderstorm characteristic which helped explain the downdraft mechanism and was included in the model. The results indicated that two conceptual models were necessary to describe the pre-storm ambient conditions ... |
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| Hughes AMRAAM Misses Target During Ninth Test. |
JUL 1986 |
|
| Authors:
|
| The Hughes aircraft AMRAAM (advanced medium range air to air missile) did not pass within lethal range of the target during the ninth test launch. The failure within the guidance system is being treated as a single component failure. |
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| Design Considerations Examined for Millimeter-Wave Defense Electronics Systems. |
JUL 1986 |
|
| Authors:
A. Cardiasmenos; FREQUENCY SOURCES INC NORTHRIDGE CA
|
| The System requirements of the Department of Defense and, to a lesser extent, the field of radioastronomy, have done much to advance the state of the art of millimeter-wave components and systems. (Author. Reprinted with permission of MSN magazine.) |
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| A Million Pulses per Second. |
JUL 1986 |
|
| Authors:
J. P. Coyne
|
| This article discusses the intensity and sophistication of the current EW aerial threat. Self-protection, countercountermeasures, target detection and reaction mode concepts are analyzed. |
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| A Three-Dimensional Mesoscale Model for the Simulation of Clouds, Precipitation and Airflow |
31 OCT 85 |
|
| Authors:
Everett C. Nickerson; NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION BOULDER CO GEOPHYSICAL MONITORING/CLIMATIC CHANGE
|
| A simulation of a heavy rainfall event has been carried out over southern France using 2-D Neph data to initialize a meso-alpha model. That model was subsequently run for a period of three hours and the resulting meteorological fields were then interpolated to a smaller grid to provide balanced initial conditions for a meso-beta model with parameterized microphysics. The meso-beta model is shown to be capable of simulating many features ... |
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| Rain Impact Assessment of Advanced Thermal Protection System Materials: Phase I Test Results |
05 SEP 1985 |
71 pages |
| Authors:
Robert M. Cooper; AEROSPACE CORP EL SEGUNDO CA MATERIALSSCIENCES LAB
|
| A rain impact test program, will study the durability of advanced thermal protection system (TPS) materials under exposure to rain conditions typical of flight. Damage threshold levels were bracketed or upper limits established for the rigid TPS materials. The borosilicate glass-coated TPS failed by flexure of the coating, and a rough correlation of rain impact resistance with the compressive modulus of the tile substrate material was found. The durability of ... |
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| Nozzle Tests for Simulating Heavy Rain in a Wind Tunnel |
JAN 1984 |
|
| Authors:
J. K. Luers; I. B. Fiscus; DAYTON UNIV OH RESEARCH INST
|
| Tests were conducted with a vibrating tube nozzle system to assess the ability of the system to realistically simulate the natural heavy rain environment at wind tunnel airspeeds of 65 to 125 mph. The nozzle system was specifically designed to achieve the large droplet sizes (-2mm) that are characteristic of the heavy rain environment. The nozzle system also produced the appropriate total water volume to simulate rain rates from 25 ... |
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| Project Deluge: A Proposed Mathematical Model for the Holloman AFB Test Track Simulated Rainfield |
01 JUL 1983 |
|
| Authors:
C. B Evans; W. L. Gilliam; ARMAMENT DIV (AFSC) EGLIN AFB FL
|
| This report relates the characteristics of the Holloman High Speed Test Track's simulated rainfield to those of a natural rainfield as defined by mathematical models propogated by other experiments. Data collected for heavy rain rates (25-30 in/hour) generated for Project Deluge in a controlled environment are analyzed and a tentative mathematical model relating the key parameters is provided. This report specifies the additional efforts required to finalize the model. (Author) ... |
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| Project DELUGE: The Development of a Holloman High Speed Test Track Heavy Rainfield |
01 JUN 1983 |
|
| Authors:
J. A. Shipe; ARMAMENT DIV (AFSC) EGLIN AFB FL
|
| The report describes the development of a Holloman High Speed Test Track artificial rainfield with a drop mass median diameter of approximately 2.7 millimeters and an accumulated rain rate of 20-30 inches per hour. An overview of the physical layout, test set-up, and test instrumentation is given. Drop number distributions over eight size categories from .3 to 5.1 millimeters are presented, as well as equivalent and accumulated rain rate, liquid ... |
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| Estimation of Rainfall Rates in Tropical Cyclones by Passive Microwave Radiometry, |
JAN 1983 |
|
| Authors:
James A. Weinman; WISCONSIN UNIV-MADISON SPACE SCIENCE AND ENGINEERING CENTER
|
| A numerical model has been developed to study the transfer of microwave radiation (6.53 to 37GHz) through a plane-parallel cloud of hydrometeors. The effects of multiple-scattering within the cloud, as well as polarization by the underlying sea surface are considered in this formulation. Model parameters characteristic of tropical cyclone rain cells over the ocean are specified, and the resulting microwave intensities emerging from cloud top are calculated. A sensitivity study ... |
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| Electric Charging by Impact of Hailstones and Raindrops, |
1983 |
|
| Authors:
H. Trinks; J. L. ter Haseborg; TECHNISCHE UNIV HAMBURG (GERMANY F R)
|
| Hailstones, raindrops, and particles are electrically charged with charge values of 10 to the 14th - 10 to the 11th As. When the particles strike the surface of aircraft of rockets, charge transfer processes occur. Especially impacting particles with high velocity generate small clouds of dust or water vapor. This effect is accompanied by strong electric charge separation processes. An impacting hailstone with a primary charge of about Q sub ... |
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| Lightning Initiation in Thunderclouds, |
1983 |
|
| Authors:
J. Latham; UNIVERSITY OF MANCHESTER INST OF SCIENCE AND TECHNOLOGY (ENGLAND)
|
| Experiments have been carried out to determine the electric field, E sub c, required to obtain corona from both ice particles and cooling drop-pairs. In the former case it was found that corona currents of about 0.1 microA and above could be obtained from ice particles a few millimetres in length for C sub c approx. 4 x 100,000 V/m for values of temperature and pressure likely to occur in ... |
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| Recent Advances in Light Scattering Calculations for Nonspherical Particles |
18 MAY 1982 |
|
| Authors:
P. W. Barber; H. Massoudi; UTAH UNIV SALT LAKE CITY
|
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| Falling Snow Optical Modeling |
NOV 1981 |
|
| Authors:
Manuel Martinez-Sanchez; David S. Dvore; John F. Ebersole; Roberto Vaglio-Laurin; Thomas E. Spaulding; AERODYNE RESEARCH INC BEDFORD MA
|
| In order to develop a model describing the adverse weather effects of snow on optical transmission, it is necessary to incorporate optical, physical, and meteorological characteristics. We report on the development of a model which incorporates these three aspects of snow characterization. We first discuss a numerical model aimed at obtaining an understanding of the meteorological aspects of snowfall. Specifically, the model accepts as inputs such measurable quantities as temperature ... |
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| Effect of Hail, Snow, and Melting Hydrometeors on Millimeter Radio Waves |
JUL 1981 |
|
| Authors:
Herbert K. Kobayashi; ARMY ELECTRONICS RESEARCH AND DEVELOPMENT COMMAND WSMR NM ATMOSPHERIC SCIENCES LAB
|
| This report is a short survey intended to present the effect of solid and melting hydrometeors on millimeter radio waves. Hail and sleet were found to be more amenable to theoretical calculation and laboratory experimentation than snow because of their simpler approximations of particle shape and dielectric constant. However, field measurements on hail and sleet are scarce in comparison to snow. The most pressing need was found to be the ... |
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| Optical Dome Protection Device. |
30 JUN 1981 |
|
| Authors:
Michael P. Bleday; DEPARTMENT OF THE AIR FORCE WASHINGTON DC
|
| A conical shaped, screen-like structured device that is positioned over, and forward of, the rain-erodible, thermal shock-susceptible optical dome of an optically guided missile which travels at varying speeds, from sub-sonic to and including supersonic, through an air environment in which raindrops are falling. This device provides raindrop erosion protection to the dome by fragmenting the raindrops before they impact on the dome; and, it also provides thermal shock protection ... |
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| Localized Deformation and Fracture of Transparent Ceramics. |
MAR 1980 |
|
| Authors:
William F. Adler; Timothy W. James; EFFECTS TECHNOLOGY INC SANTA BARBARA CA
|
| The objective of this research is to understand and model the deformation and fracture response of materials exposed to water drop collisions. Due to the inherent complexity of the erosive response of materials exposed to a multiple water drop environment, this investigation concentrated on a very idealized water drop impact condition: the normal impact of a spherical water drop on a plane surface. Impact experiments were conducted in a specially ... |
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| Atmospheric Effects on Millimeter Radio Waves |
JAN 1980 |
56 pages |
| Authors:
H. K. Kobayashi; ARMY ELECTRONICS RESEARCH AND DEVELOPMENT COMMAND WSMR NM ATMOSPHERIC SCIENCES LAB
|
| This report is a short survey intended to present the atmosphere's effect on millimeter waves. The emphasis is on rain and raindrop-size distributions. This emphasis is appropriate because rain (the most common nongaseous constituent of the lower atmosphere) also has the greatest effect on millimeter waves, and raindrop-size distribution is needed to compute the theoretical and measured extinction of radio waves. The pressing need to acquire short-time data on raindrop-size ... |
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| Liquid and Solid Particle Impact Erosion |
NOV 1979 |
|
| Authors:
George F. Schmitt Jr; AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OH
|
| The state-of-the-art in liquid drop impact and solid particle impact erosion is reviewed with emphasis on erosion mechanisms, prediction techniques, and materials properties effects. Erosion data sources, materials used to resists erosion, and design techniques are described. A bibliography of key references in the erosion literature is also presented. |
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| Comparison of Radar Derived Rain Attenuation with the COMSTAR Beacon at 28.56 GHz for Summer and Winter Periods, |
JUL 1979 |
|
| Authors:
Julius Goldhirsh; JOHNS HOPKINS UNIV LAUREL MD APPLIED PHYSICS LAB
|
| A description of new results is given pertaining to an experiment whose aims are to test and improve the accuracy of radar derived slant path rain attenuation methods. These estimated results are compared with measured rain fade levels of the COMSTAR beacon signal at 28.56 GHz at Wallops Island, Virginia. The new data base corresponds to five rain days flanking the winter of 1978-79 during which 715 minutes of simultaneous ... |
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| Rain Erosion Resistance of Materials for Forward Looking Infrared Windows. |
APR 1978 |
|
| Authors:
Douglas W. Amlin; AERONAUTICAL SYSTEMS DIV WRIGHT-PATTERSON AFB OH DIRECTORATE OF AVIONICS ENGINEERING
|
| This report summarizes the theory and data which has been compiled to date on the rain erosion resistance of Zinc Sulfide, Zinc Selenide and Gallium Arsenide. In addition, it formulates a method by which the usefulness of these and other IR materials in operational systems can be predicted. A review of available test data and theoretical analyses leads to the formulation of a method for predicting the rain erosion resistance ... |
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| Investigation of the Method of Effect on Convective Clouds with the Aid of Surface Active Compounds, |
03 JAN 1978 |
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| Authors:
Ye. Ye. Korniyenko; M. V. Tovbin; A. I. Furman; FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO
|
| During the development of the methods of the artificial causing of precipitation, as under the influence on other weather processes, main condition is at present the detection of those components of the process of the formation of the precipitation in which, with the aid of microeffects, it is possible to obtain macroscopic effect. This condition is caused by the facts that energy of precipitation-forming processes considerably exceeds the energy possibilities ... |
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Reports by Keyword(s)
RAINDROPS
