Which north reference systems are involved when converting azimuths on a map?

• A. True north
• B. Grid north
• C. True north, Grid north, and Magnetic north
• D. Magnetic north

Answer: (C)

Azimuths are directions defined relative to a reference line, and maps can orient that reference in three ways: true north (geographic north toward the poles), grid north (the direction along the map’s grid lines), and magnetic north (the direction a compass points). When you convert a bearing on a map, you may need to move between any of these references depending on what your source uses and what you’re comparing it to. The grid on a map is usually not perfectly aligned with true north because of grid convergence, and the compass reading points to magnetic north, which shifts with location and time due to magnetic variation. So to interpret, transfer, or reconcile azimuths across navigation tools and map grids, you must account for true north, grid north, and magnetic north. That’s why all three are involved.