Range of Detection of Small Air Objects by the Grounding Noise Receivers System

Abstract

The paper considers the problem of detecting small air objects by a ground-based noise-tracking system with the concomitant definition of the detection range in conditions to the real noise-signal situation. As the receiving system, a group of receivers is chosen as well as -devices, which is designed as a linear discrete equidistant acoustic antenna. A small air object is represented by a "Drone with a screw-ring propulsor in a push arrangement".

For calculations was attracted the data about the loss to the expansion of the of acoustic waves front, data on spatial attenuation, on the influence of climatic factors and green plantations, as well as on the features of the "c- profile" and the terrain.

The emergence of a significant interest in the use of acoustic means for detecting, positioning and detecting elements of small airspace movement has led to the development of directions for the creation of mobile noise reduction devices that implement the principles of detecting sources of specific noise for conventional hydroacoustics. Such objects can include unmanned flying vehicles of various purposes - helicopter ("rotor") or airplane type ("wing"). The solution to this problem should be based on accurate information about the acoustic field of the source of specific noise and on the modes of motion of the object. Unfortunately, the information about the noise characteristics of airspace is extremely limited, but the widely available sources of information are mainly focused not on the advertising side of this issue. In this regard, the proposed material will be timely and timely, and the solution to the problem of detecting these objects with the associated definition of the predicted range of noise detectors in the conditions of a given model of spatial noise load - represents the purpose of the work. It is proposed to identify small wing objects of airborne objects at altitudes and at speeds that correspond to their technical characteristics in normal refraction. The probability of false alarms using the Neumann-Pearson criteria should be no more than 0.01. Survey Sector - selected according to the directional characteristics of the receiving system with the possibility of mechanical scanning in the sector. The operating frequency band of the receiving system is formed, based on the frequency characteristics of noise and the range of working speeds of airspace. It is proposed to determine the sloping "predicted" range taking into account the "energy" and "geometric" range. Before calculations, losses data on the expansion of the front of the acoustic waves, the data on the spatial decay, the influence of climatic factors and green plantations, as well as features of the "profile" and features of the terrain, in the form of "engineering structures" should be drawn.

Ref. 14, fig. 2, tabl. 1.