Surveying fundamentals: Is the bearing of a line defined as its horizontal angle measured from magnetic south, or is it referenced from a different directional meridian?

Introduction / Context:
Bearing is a core concept in land surveying and mapping. It specifies the direction of a line relative to a reference meridian so field crews, designers, and GIS professionals can communicate orientation unambiguously. This item checks whether the reference is magnetic south or the standard surveying meridians.

Given Data / Assumptions:

• Bearing is a horizontal angle used for line direction in surveying.
• Common meridians are true (geodetic) north, magnetic north, or grid north of a mapped projection.
• Survey texts define quadrant bearings from north or south toward east or west, but the zero reference is north–south lines, not specifically magnetic south.

Concept / Approach:
In practice, a bearing is measured from a north–south reference. Azimuths are measured clockwise from north 0–360 degrees. Quadrant bearings are noted as N or S first, followed by an angle less than 90 degrees, then E or W (for example, N 35° E). The meridian used (true, grid, or magnetic) must be specified, but it is not exclusively magnetic south.

Step-by-Step Solution:

Verification / Alternative check:
Check any standard surveying handbook: bearings are tied to a specified meridian, typically true or grid north; magnetic references are possible but must be stated and are not limited to “from magnetic south.”

Why Other Options Are Wrong:

Common Pitfalls:
Confusing bearings (quadrant format) with azimuths (0–360 from north); assuming magnetic is always the reference; ignoring local declination when using magnetic readings.

Final Answer:
Incorrect