The Experts below are selected from a list of 6 Experts worldwide ranked by ideXlab platform

Stewart, Harold S. - One of the best experts on this subject based on the ideXlab platform.

  • An analog study of the distribution of radiant energy from an Aerial explosion occurring below a cloud overcast
    University of Rochester, 2017
    Co-Authors: Minott P. O., Stewart, Harold S.
    Abstract:

    Thesis (M.S.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics, 1961.The purpose of this experiment was to determine the radiant energy which objects in the vicinity of an explosion receive. The experiment analyzed the effects of Aerial Explosions which occur below an overcast of clouds. When an Aerial explosion occurs on a cloudless day, nearly half of the radiant energy it releases radiates harmlessly into space. The remainder radiates toward the earth and is either absorbed or singly scattered into space. This type of explosion exposes only those objects which are in direct line of sight. However, when an explosion of equal yield occurs below an overcast of clouds, the half of the radiant energy which was formerly harmlessly radiated into space, is now diffusely scattered back towards the earth. In addition, the energy which was singly scattered from the earth strikes the overcast and is partially scattered back to earth. The result of these two effects is a multiple scattering which causes the exposure on objects near the explosion to be greater than the exposure which would occur on a clear day. Also, in this case objects not directly exposed to the explosion may be indirectly exposed by scattering from the cloud overcast. Figures 1 and 1(a) show the manner in which the energy from the explosion is distributed. These diagrams show the paths of only a few rays. Because of the complex nature of the multiple scattering between the earth and cloud overcast, mathematical computation of the radiant energy received by objects in the vicinity of an explosion was difficult. Due to this difficulty, an analog solution of the problem was used. Two planes were constructed and mounted in parallel to simulate the surfaces of the earth and cloud overcast. Between these planes, a small point source of light was placed to represent the explosion. At points throughout this model of the explosion and its environment, measurements of illumination were made. These measurements were correlated, by equations derived for this purpose, to the exposures which would occur in an actual explosion

Minott P. O. - One of the best experts on this subject based on the ideXlab platform.

  • An analog study of the distribution of radiant energy from an Aerial explosion occurring below a cloud overcast
    University of Rochester, 2017
    Co-Authors: Minott P. O., Stewart, Harold S.
    Abstract:

    Thesis (M.S.)--University of Rochester. College of Engineering and Applied Science. Institute of Optics, 1961.The purpose of this experiment was to determine the radiant energy which objects in the vicinity of an explosion receive. The experiment analyzed the effects of Aerial Explosions which occur below an overcast of clouds. When an Aerial explosion occurs on a cloudless day, nearly half of the radiant energy it releases radiates harmlessly into space. The remainder radiates toward the earth and is either absorbed or singly scattered into space. This type of explosion exposes only those objects which are in direct line of sight. However, when an explosion of equal yield occurs below an overcast of clouds, the half of the radiant energy which was formerly harmlessly radiated into space, is now diffusely scattered back towards the earth. In addition, the energy which was singly scattered from the earth strikes the overcast and is partially scattered back to earth. The result of these two effects is a multiple scattering which causes the exposure on objects near the explosion to be greater than the exposure which would occur on a clear day. Also, in this case objects not directly exposed to the explosion may be indirectly exposed by scattering from the cloud overcast. Figures 1 and 1(a) show the manner in which the energy from the explosion is distributed. These diagrams show the paths of only a few rays. Because of the complex nature of the multiple scattering between the earth and cloud overcast, mathematical computation of the radiant energy received by objects in the vicinity of an explosion was difficult. Due to this difficulty, an analog solution of the problem was used. Two planes were constructed and mounted in parallel to simulate the surfaces of the earth and cloud overcast. Between these planes, a small point source of light was placed to represent the explosion. At points throughout this model of the explosion and its environment, measurements of illumination were made. These measurements were correlated, by equations derived for this purpose, to the exposures which would occur in an actual explosion

Ballard Courtney - One of the best experts on this subject based on the ideXlab platform.

  • Data from: Explosion-generated infrasound recorded on ground and airborne microbarometers at regional distances
    Data Archiving and Networked Services (DANS), 2026
    Co-Authors: Young, Eliot F., Bowman, Daniel C., Lees, Jonathan M., Klein Viliam, Arrowsmith, Steven J., Ballard Courtney
    Abstract:

    Recent work in deploying infrasound (low frequency sound) sensors on aerostats and free flying balloons has shown them to be viable alternatives to ground stations. However, no study to date has compared the performance of surface and free floating infrasound microbarometers with respect to acoustic events at regional (100s of kilometers) range. The prospect of enhanced detection of Aerial Explosions at similar ranges, such as those from bolides, has not been investigated either. We examined infrasound signals from three 1 ton TNT equivalent Explosions using microbarometers on two separate balloons at ranges of 280 to 400 km and ground stations at ranges of 6.3 to 350 km. Signal celerities were consistent with acoustic waves traveling in the stratospheric duct. However, significant differences were noted between the observed arrival patterns and those predicted by an acoustic propagation model. Very low background noise levels on the balloons were consistent with previous studies that suggest wind interference is minimal on freely drifting sensors. Simulated propagation patterns and observed noise levels also confirm that balloon-borne microbarometers should be very effective at detecting Explosions in the middle and upper atmosphere as well as those on the surface

Young, Eliot F. - One of the best experts on this subject based on the ideXlab platform.

  • Data from: Explosion-generated infrasound recorded on ground and airborne microbarometers at regional distances
    Data Archiving and Networked Services (DANS), 2026
    Co-Authors: Young, Eliot F., Bowman, Daniel C., Lees, Jonathan M., Klein Viliam, Arrowsmith, Steven J., Ballard Courtney
    Abstract:

    Recent work in deploying infrasound (low frequency sound) sensors on aerostats and free flying balloons has shown them to be viable alternatives to ground stations. However, no study to date has compared the performance of surface and free floating infrasound microbarometers with respect to acoustic events at regional (100s of kilometers) range. The prospect of enhanced detection of Aerial Explosions at similar ranges, such as those from bolides, has not been investigated either. We examined infrasound signals from three 1 ton TNT equivalent Explosions using microbarometers on two separate balloons at ranges of 280 to 400 km and ground stations at ranges of 6.3 to 350 km. Signal celerities were consistent with acoustic waves traveling in the stratospheric duct. However, significant differences were noted between the observed arrival patterns and those predicted by an acoustic propagation model. Very low background noise levels on the balloons were consistent with previous studies that suggest wind interference is minimal on freely drifting sensors. Simulated propagation patterns and observed noise levels also confirm that balloon-borne microbarometers should be very effective at detecting Explosions in the middle and upper atmosphere as well as those on the surface

Bowman, Daniel C. - One of the best experts on this subject based on the ideXlab platform.

  • Data from: Explosion-generated infrasound recorded on ground and airborne microbarometers at regional distances
    Data Archiving and Networked Services (DANS), 2026
    Co-Authors: Young, Eliot F., Bowman, Daniel C., Lees, Jonathan M., Klein Viliam, Arrowsmith, Steven J., Ballard Courtney
    Abstract:

    Recent work in deploying infrasound (low frequency sound) sensors on aerostats and free flying balloons has shown them to be viable alternatives to ground stations. However, no study to date has compared the performance of surface and free floating infrasound microbarometers with respect to acoustic events at regional (100s of kilometers) range. The prospect of enhanced detection of Aerial Explosions at similar ranges, such as those from bolides, has not been investigated either. We examined infrasound signals from three 1 ton TNT equivalent Explosions using microbarometers on two separate balloons at ranges of 280 to 400 km and ground stations at ranges of 6.3 to 350 km. Signal celerities were consistent with acoustic waves traveling in the stratospheric duct. However, significant differences were noted between the observed arrival patterns and those predicted by an acoustic propagation model. Very low background noise levels on the balloons were consistent with previous studies that suggest wind interference is minimal on freely drifting sensors. Simulated propagation patterns and observed noise levels also confirm that balloon-borne microbarometers should be very effective at detecting Explosions in the middle and upper atmosphere as well as those on the surface