Розробка методу адаптації систем радіоакустичного зондування атмосфери до метеорологічної ситуації

The object of research is the process of ensuring the Bragg condition between the lengths of acoustic and electromagnetic waves when measuring the altitude profiles of the atmosphere using the radioacoustic sounding (RAS) method. The problem solved in the work is the lack of a generalized theoretical basis for developing methods for adapting RAS systems to maintain the Bragg condition during the movement of the acoustic wave packet (AWP) in the atmosphere. In the work, using the theory of stochastic optimal control, a method for frequency adaptation of RAS systems was developed to ensure the Bragg condition along the sounding path. The method includes the operations of estimating the speed of sound, stochastic linear filtering of the AWP state parameter vector and controlling the frequency of the radio signal based on the obtained data. A method for estimating the information parameters of the signal was proposed, and an algorithm for sequential filtering of AWP parameters was developed. The developed frequency adaptation method will significantly improve the quality indicators of RAS systems – the accuracy of measuring atmospheric temperature profiles and the efficiency of sounding. The use of the method in practice will also allow to increase the range of sounding systems by more effectively adjusting to the Bragg conditions at small values of the signal-to-noise ratio, characteristic of long ranges. The improvement of the main characteristics of the systems is achieved by more accurately ensuring the Bragg condition in the process of measuring the sound speed values, as a result of which the measurement results do not have systematic errors, and the random component of errors is significantly reduced. Therefore, the averaging time of individual measurement results to achieve the required integral accuracy of estimating the atmospheric temperature profile is significantly reduced, from tens to units of minutes. The proposed method can be implemented in practice by improving the existing RAS atmospheric systems manufactured by industry.