For a third-order geodetic control network established by traverse, the position closure after azimuth adjustment should be at least as good as which ratio?

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

Answer: (C)

Position closure after azimuth adjustment shows how well the traverse network closes in plan once the measured directions are adjusted. For a third-order geodetic control network, the accepted threshold is that this closure should be no worse than 1:20,000. This means the total horizontal misclosure along the network must be less than the traverse length divided by 20,000—so a 40 km traverse would have to close within about 2 meters. Choices with looser tolerances (1:50,000 or 1:100,000) wouldn’t meet the third-order standard, while a stricter tolerance (1:10,000) is more demanding than required but still acceptable. The 1:20,000 standard is the typical benchmark for third-order networks after azimuth adjustment.