What aspect does a higher elevation mask in GNSS receptions do?

A higher elevation mask in GNSS (Global Navigation Satellite System) receptions limits the number of satellites available for positioning. The elevation mask refers to the minimum angle above the horizon that a satellite must be at for its signals to be considered in the positioning calculations. When the elevation mask is set higher, typically above 10 to 15 degrees, it prevents the utilization of signals from satellites that are closer to the horizon.

This is significant because lower-lying satellites may have their signals obstructed by buildings, trees, or other obstacles, which can lead to reduced signal quality and accuracy in position calculations. By limiting the satellites to those at higher elevations, receivers can select from signals that are less likely to be affected by these obstructions, thus influencing the overall satellite count that can be reliably used for positioning. This practice ensures a clearer sky view for the satellites that are being tracked, but it does indeed reduce the total number of satellites that the receiver can use, hence potentially impacting the overall accuracy and reliability of positioning if the remaining satellites are not sufficiently spread across the sky.