In GNSS, how does satellite geometry affect observations?

In Global Navigation Satellite Systems (GNSS), satellite geometry refers to the configuration and relative positions of satellites in the sky at any given time. This geometry significantly impacts the accuracy and reliability of GNSS observations.

When satellites are well-distributed across the sky, the geometry allows for better triangulation of positions. A more favorable satellite geometry – meaning satellites are positioned in such a way that they are not clustered together but rather are spread out – results in improved accuracy of the calculated position. It reduces potential errors in atmospheric delays, multipath effects, and increases the overall precision of the positioning data.

Conversely, if the satellites are close together or almost in line, the geometry becomes less favorable, potentially leading to greater uncertainty in the measurements. This phenomenon is often represented through concepts like the Dilution of Precision (DOP), which quantitatively describes how positional accuracy is affected by satellite geometry.

In summary, a good satellite configuration enhances the quality of observations and leads to improved accuracy, making it crucial for effective GNSS positioning.