What is the first order accuracy standard for NGS horizontal distance?

• A. 1: 50,000
• B. 1: 20,000
• C. 1: 100,000
• D. 1: 10,000

Answer: (C)

The first order accuracy standard for the National Geodetic Survey (NGS) horizontal distance is specified as 1:100,000. This means that for every 100,000 units of horizontal distance measured, the maximum allowable error is 1 unit. This high standard ensures a high level of precision and reliability in surveying work, which is critical for accurate mapping, engineering projects, and other applications that depend on precise geographic data.

Having a first-order accuracy standard of 1:100,000 reflects the rigorous quality control measures set by NGS to maintain consistent and dependable geodetic measurements across various surveying applications, thus supporting federal, state, and local surveying activities effectively. This establishes a benchmark for surveyors to gauge their measurement accuracy in comparison to these national standards.