Features of using simulation modeling in the development of next-generation radio telemetry systems for ensuring flight tests of rocket and space technology objects

Problem statement. Tests and intended use of rocket and space technology facilities are accompanied by monitoring of their technical condition and monitoring of various natural and man-made processes, for which various radio telemetry systems are being developed. An important task at the present stage of the development of the test base is the development and implementation of approaches to optimize the structure and composition of radio telemetry systems, as well as the characteristics of its components for the requirements of a specific flight test, including taking into account the many changing characteristics of the radio channel, depending on the type of test object, the dynamic parameters of its trajectory, the conditions of a particular test site and even the time of year. Under such conditions, simulation modeling is a tool necessary to assess the condition of a non-stationary radio channel of a radio telemetry system, to select the optimal characteristics of the radio channel equipment, as well as to conduct research on the effectiveness of certain technical solutions in the creation and further improvement of digital radio channel equipment. Goal. To consider the existing models of radio channels of communication systems and identify their main disadvantages, to develop a mathematical simulation model of a new-generation radio telemetry system with advantages over existing models, and to determine the prospects for its improvement. Results. The disadvantages of existing models of radio channels of communication systems have been identified. A new generation simulation mathematical model of a radio telemetry system has been developed, which has such advantages over existing models as accounting for the error of synchronization systems, accounting for signal attenuation due to the polarization mismatch of the transmitting and receiving antennas, accounting for the rotation of the signal source around the longitudinal axis, accounting for the movement of the signal source and receiver. The model takes into account the signal structure used, its encoding methods, digital signal processing algorithms, principles for increasing noise immunity with spaced reception, estimating the power of diffusely scattered and reflected radiation components from the underlying surface, and the model takes into account for losses caused by the influence of plasma generated by the movement of high-speed objects in dense atmospheric layers. The software implementation of the model makes it possible to calculate the reliability of receiving information (the probability of bit and packet errors, bandwidth, reception reliability), determine the optimal placement of measuring (receiving) points of various bases in accordance with the described criterion, determine the requirements for individual characteristics of the radio telemetry system, ensuring the achievement of the required information content of the system and the reliability of receiving information transmitted from the test facility, if necessary, add additional parameters and functionality to the program. Further improvement of the developed simulation model is seen in deeper consideration of the effect on the passage of the telemetric signal of the plasma envelope surrounding the test object upon entry into the dense layers of the atmosphere. Practical significance. The results can be used in the development and defining characteristics of new-generation radio telemetry systems to ensure flight tests of rocket and space technology facilities, and to conduct research on the effectiveness of certain technical solutions.