COMPUTER ANALYSIS OF THE OPERATING CONDITIONS OF THE RADIO CHANNEL OF THE VHF/UHF RANGE TAKING INTO ACCOUNT ZONES OF ELECTROMAGNETIC ACCESSIBILITY OF RADIO EMISSION SOURCES

The paper considers a technique for computer analysis of the working conditions of a VHF/UHF radio channel, taking into account the zones of electromagnetic accessibility of radio emission sources in relation to a topographic map, depending on the terrain characteristics. Based on the known models of radio signal propagation, mathematical relationships are obtained to determine the boundaries of the electromagnetic accessibility of a radio emission source as part of a mobile radio communication channel on a topographic map of the area. This takes into account the sensitivity of the receiver, the power of the transmitter and the shape of the digitized radiation pattern of its antenna, the scale of the map, and the loss of transmitter power depending on the characteristics of the terrain. On the basis of a modified wave algorithm, a method is proposed for calculating the boundaries of the zone of electromagnetic accessibility of radio facilities of a radio communication channel on a topographic map of the area. The method is characterized by simplicity, high speed and reliability of calculations. Already known techniques for modeling the propagation of a radio signal can be easily integrated into the proposed algorithm. The shape of the electromagnetic accessibility zone is determined by the digitized radiation pattern of the transmitter antenna, obtained using special software. The size of the EMI zone depends on the power and frequency of the radio transmitter, the power loss for signal propagation, and the sensitivity of the radio signal receiver. A technique for computer analysis of the working conditions of the VHF/UHF radio channel has been developed and implemented in the program for the operational support of the operation of mobile radio communications used in tactical levels of command and control of units and subdivisions of law enforcement agencies of Ukraine. Practical examples show the expediency of calculating the electromagnetic availability of radio facilities on a map of the area with a tactical situation in the tasks of assessing the performance of a mobile radio communication channel.