Which statement about almanac data is true?

• A. It provides instantaneous position of satellites measured by the receiver's internal clock.
• B. It is information the GPS receiver can obtain from one satellite describing the approximate orbital positioning of all satellites in the constellation.
• C. It indicates the exact ephemeris corrections to each satellite.
• D. It provides the ionospheric delay data at the receiver's location.

Answer: (B)

Almanac data contains coarse, long-term orbital information for every satellite in the constellation. Its main purpose is to let the receiver know where to look for satellites and to predict their general positions over the coming days to weeks, which helps with quick satellite acquisition. This data can be obtained from a single satellite and used to infer the approximate orbital positions of all satellites, making it the best choice among the options. It’s not about instantaneous satellite positions—that requires precise ephemeris data for each satellite. It doesn’t provide exact per-satellite ephemeris corrections, which are a separate, more precise dataset, and it isn’t the source of ionospheric delay data for the receiver’s location.