What are the different types of LOB fixes?

• A. Single LOB, DF Fix, Over the Horizon
• B. Double LOB, DF Fix, Over the Horizon
• C. Single LOB, DF Fix, Near the Horizon
• D. Single LOB, Fix DF, Over the Horizon

Answer: (A)

LOB fixes are position fixes based on lines of bearing to known references. The three types you’re expected to know are single LOB, DF fix, and over the horizon. A single LOB uses the bearing to one reference point, placing you somewhere along that line; you’d need another independent line or distance information to pinpoint the exact location. A DF fix relies on bearings from multiple direction-finding sources; where those bearing lines cross gives your precise position. An over the horizon fix uses signals received beyond the visible horizon to build a fix, often combining LOB data with distant references to solve your location. The other options use terms that aren’t standard or mix up the wording, so they don’t fit the established categories.