SIMULATION MODEL OF GNSS COORDINATE-TIME REFERENCE IN ENVIRONMENTAL MONITORING

Abstract. It is necessary to monitor the environment to control the state and assess the negative dynamics of changes in the environmental situation. In the case of long-term forecasting of environmental quality, monitoring makes it possible to prevent or reduce the risks of deterioration of environmental conditions within the boundaries of the territory under consideration at the time of observation. To determine these boundaries and time intervals, coordinate-time reference is used using various methods. For the time being, high accuracy, specified regularity and automation of information acquisition can only be achieved using global navigation satellite systems (GNSS). The GNSS receiver works best when there is a direct line of sight to the satellites transmitting navigation signals. Obscuring the receiver antenna with objects that violate this condition leads to a decrease in the accuracy of the coordinate-time reference. In addition, when monitoring the environment in forestland, it is necessary to consider the attenuation of GNSS signals by vegetation. To plan monitoring sessions with coordinate-time reference, a simulation model is required that includes these factors. Such a model makes it possible to predict the best time for carrying out coordinate-time referencing sessions.