What element does a pseudorange measurement include that enables estimation of receiver clock error?

• A. Satellite clock bias included in measurement.
• B. Attitude angles.
• C. Receiver clock bias included in measurement.
• D. Only geometric distance.

Answer: (C)

Pseudorange measurements are not just the geometric distance to a satellite; they include a term for the receiver’s clock error. This receiver clock bias appears in the observation equation as an extra bias, effectively linking the measured time difference to the receiver’s time offset from true GPS time. By treating this bias as an unknown alongside position, you can solve for the receiver’s clock error when you have enough satellites (typically four or more). Satellite clock bias is also part of the model, but it’s the receiver clock bias term that enables estimating the receiver’s time error. Attitude angles don’t enter the pseudorange measurement, and using only geometric distance would leave the clock error unresolved.