How do you decrease satellite clock error?

• A. Calibrate the receiver
• B. Replace satellites
• C. Increase the number of satellites
• D. Use a different constellation

Answer: (C)

The main idea is that satellite clock error is part of the set of quantities the receiver must estimate from the pseudorange measurements. Each additional satellite provides another independent observation, overdetermining the navigation solution. With more satellites, the receiver can better separate the receiver’s clock bias from the satellites’ clock errors and refine the estimated corrections, reducing the impact of any single satellite’s clock error on position accuracy.

Calibrating the receiver or changing the constellation doesn’t directly reduce the actual satellite clock errors; replacing satellites isn’t feasible, and changing the constellation doesn’t inherently improve the clock error correction in a given solution. Increasing the number of satellites gives the best chance to minimize the effect of satellite clock errors through a more robust, well-constrained solution.