Which aspect of GPS error is related to inaccuracies in the satellite's calculated position?

Ephemeris errors refer to inaccuracies in the satellite's calculated position due to various factors, including gravitational influences, perturbations, and orbital decay. When a satellite's position is not precise, it affects the accuracy of the GPS signals that are transmitted to receivers on the ground. The accuracy of these positions is crucial because GPS relies on the precise calculation of distances between the satellite and the receiver to determine a location. If the satellite's reported position contains errors, the calculated distance will also be incorrect, leading to positioning errors in the GPS receiver on Earth.

In contrast, multipath errors occur when signals bounce off surfaces, atmospheric effects are related to interference from the Earth's atmosphere, and signal noise pertains to random variations in signal strength and quality. While these factors can affect the overall accuracy of GPS readings, they do not specifically relate to inaccuracies in the satellite's own calculated position, which is the defining characteristic of ephemeris errors. Understanding how ephemeris errors impact GPS accuracy is crucial for effective surveying and geospatial analysis.