The value of the object tmnxPortGnssElevationMaskAngle specifies the the elevation mask angle. It provides a method of filtering satellites to be used by the system. Elevation angle is the angle above the horizon. When satellites are close to horizon, there is more atmosphere, troposphere, and ionosphere for the signals to go through (ie. more noise). Elevation angle mask determines the minimum elevation angle below which the GNSS receiver module will not use a satellite in its computations. Typical values are 10 and 15 degrees.