Question

Which of the following is the set of classification of static GPS surveying technology?

• A. Short and Long base lines
• B. Short and Normal base lines
• C. Long and Medium base lines
• D. Long and Normal base lines

Hint:

In static GPS, the baseline length is the most critical factor.
- Short Baseline (< 20 km): Errors cancel out easily, high accuracy is straightforward.
- Long Baseline (> 20 km): Atmospheric errors are a major challenge, requires advanced processing.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks for the standard classification of static GPS surveying techniques based on the length of the baseline being measured.

Step 2: Detailed Explanation:
Static GPS surveying is a high-precision technique where two or more receivers collect satellite data simultaneously over a period of time. The data is then post-processed to determine the precise three-dimensional vector (the baseline) between the receivers. The processing strategies and achievable accuracy depend on the length of this baseline.
The classification is typically divided based on the scale of the survey:

• Short Baselines: Generally considered to be baselines up to 10-20 km. Over these distances, the ionospheric and tropospheric errors are highly correlated between the two receivers and can be effectively eliminated through differential processing. Very high accuracy (millimeter level) can be achieved relatively quickly.

• Long Baselines: Baselines longer than 20-30 km. Over these distances, the atmospheric errors are less correlated, and more advanced processing techniques, longer observation times, and precise satellite orbit data are required to achieve high accuracy.


Some classifications might include a "medium" or "normal" category, but the most fundamental and common division is between "Short" and "Long" baselines, as the processing strategy changes significantly between these two regimes. The set "Short and Long base lines" encompasses the entire range of static GPS surveying.

Step 3: Final Answer:
The set of classification for static GPS surveying technology is Short and Long base lines.