How far should LOPs be?

• A. 30°
• B. 45°
• C. 90°
• D. 60°

Answer: (D)

LOPs come from two independent measurements, and the fix you get is where those lines intersect. The reliability of that intersection depends on how far apart the lines are. If the lines are nearly parallel, even small measurement errors translate into a big error in position. When the lines are separated by a larger angle, the intersection becomes much more stable. The standard minimum separation that gives a usable, reliable fix is about 60 degrees. So among the options, sixty degrees is the appropriate distance. A smaller separation like 30° or 45° would be too uncertain, while a 90° separation would be even better but isn’t the minimum requirement.