Fast-static surveys differ from traditional static surveys primarily in what aspect?

• A. They use only one receiver.
• B. The length of the GPS observation time ranges from 8 to 30 minutes.
• C. They do not require a base station.
• D. They rely on leveling techniques for elevation only.

Answer: (B)

Fast-static surveys are defined by shorter data-collection sessions at each setup compared to traditional static surveys. In fast-static, you gather GNSS data for only a brief window at each point—on the order of minutes, commonly around 8 to 30 minutes—so you can cover more locations in less time. Even with these shorter sessions, you still use a base station to provide differential corrections, which preserves accuracy through post-processing. The main distinction is not how many receivers you use, nor whether you level for elevation, but how long you observe at each setup. The other statements don’t fit because a base station is still required and leveling isn’t the method used to achieve the positioning.