Azimuth correction due to height is applied under which condition?

Azimuth correction due to height is applied under which condition?

• A. Always for any observation
• B. When the observed point is at height above or below the ellipsoid surface
• C. Only at the equator
• D. Only for height adjustments less than 1 meter

Answer: (B)

Height influences the geometry of the sight line relative to the reference ellipsoid. The azimuth is measured in the local horizontal plane, so if the observed point sits above or below the ellipsoid, the line of sight is tilted away from that tangent horizontal plane. This tilt changes the horizontal projection of the line and introduces an azimuth error unless a height-based correction is applied. If the observed point were exactly on the ellipsoid surface, there would be no height difference to cause this tilt, so no correction is needed. Therefore, azimuth correction due to height is required whenever the observed point has height above or below the ellipsoid surface.

Height influences the geometry of the sight line relative to the reference ellipsoid. The azimuth is measured in the local horizontal plane, so if the observed point sits above or below the ellipsoid, the line of sight is tilted away from that tangent horizontal plane. This tilt changes the horizontal projection of the line and introduces an azimuth error unless a height-based correction is applied. If the observed point were exactly on the ellipsoid surface, there would be no height difference to cause this tilt, so no correction is needed. Therefore, azimuth correction due to height is required whenever the observed point has height above or below the ellipsoid surface.