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Ionospheric Effects for Nuclear Explosions Monitoring


Development of a Remote Ionospheric Method for Detecting Underground Nuclear Explosions

Tech Area / Field

  • INS-DET/Detection Devices/Instrumentation

3 Approved without Funding

Registration date

Leading Institute
Institute of Ionosphere, Kazakstan, Almaty


  • Lawrence Livermore National Laboratory / University of California, USA, CA, Livermore

Project summary

The objective of the project is to develop scientific and technological base for remote monitoring and identifying underground nuclear explosions using ionospheric radio sounding.

The project is aimed to solve the problem of remote detecting, identifying and estimating the yield of an underground nuclear explosion.

Institute of Ionosphere is only of the institutes of Former Soviet Union that organized and successfully carried out the detection of ionospheric effects due to series of chemical and underground nuclear explosions. It was possibility because authors of the project had worked out special method to make measurements of Doppler shift when multi - ray signal comes to receiver. Accuracy of this method is by an order better of standard methods. As a result it was obtained unique experimental data during 10 surface chemical and 19 underground nuclear explosions. Authors of the project developed theoretical models and computer simulation codes that account for the entire range of atmospheric and ionospheric phenomena involved in the technique, from the generation of the acoustic pulse at or near the surface of the ground to the synthesis of radiofrequency signatures recorded by ionospheric radar systems. The model was tested using surface chemical explosions. The model is in a better agreement with experiment than the familiar models. As a result the authors of the project found main regularities of space-time structure of acoustic field and ionospheric disturbances during point chemical explosions. The model accounts nonlinear effects, atmosphere and ionosphere vertical inhomogenity, absorption, diffraction effects, geomagnetic field etc. You can make model calculations for every point of the Earth with account of atmosphere and ionosphere local regularities.

The main advantage of remote monitoring of explosions with radio physical method (ionospheric method) is the possibility "to look" from a height of 100-300 km above the explosion site directly at the earth’s surface. Furthermore, the ionospheric method has an important advantage. When you look from the height 100-300 km directly at the earth’s surface, the information is integrated over a large surface, and errors due to a nonuniform surface, a local inhomogeneity of soil and an inhomogeneity of shock wave field are reduced. So you can estimate the whole flux of energy across the ground surface. Because of this reasons the ionospheric method is more accurate then others used the measurements at separate points Then the ionospheric method can separate explosions with complete and incomplete containment, above ground point chemical explosion and underground nuclear explosion. It is a chance to separate an earthquake and underground nuclear explosion too. Acoustic field of underground nuclear explosion has the cylindrical symmetry and acoustic field of earthquake does not have it.

Evidently, to increase reliability of remote detecting and identifying underground nuclear explosions it is necessary to unite seismic and ionospheric methods.

During the course of the project the following results are expected to be obtained:

· Physical model and package of computer simulation codes to describe acoustic and ionospheric phenomena associated with surface and underground explosions will be developed.

· The quantitative estimation of efficiency of energy transport mechanism from underground sources into the upper atmosphere will be obtained.

· The method to determine the yield of explosion using parameters of ionospheric response on the explosion will be carried out.

· Ultimate sensitive of ionospheric method for detection of small explosions will be determined.

· General recommendations how to choose optimum conditions of ionospheric radio sounding over explosion site will be developed, for example, altitudes and frequencies of radio sounding, ultimate distances of reflection heights of the radio waves from the epicenter of explosion and so on.

· Comparative characteristics of ionospheric method will be obtained to determine its place amount other methods.

· The method to separate an earthquake and underground nuclear explosion, above ground point chemical explosion and underground nuclear explosion, explosions with complete and incomplete containment will be developed.

· A breadboard model consisting of apparatus and computer to detect automatically above ground and underground explosions and to increase the sensitivity of ionospheric method will be worked out. It is expected that the cost of the design and the industrial prototype may be low because you can use standard technical apparatus to prepare it.

Foreign collaborators potential role

Cooperation with foreign collaborators is necessary during all three years of the project duration. It is expected that collaborators will take part in annual meeting to discuss the results of research works, contribute in consultations, technical advising etc. for the following tasks: acoustic source model at the explosion site, the propagation of acoustic waves through the atmosphere and ionosphere, the propagation of radio wave and so on.