Reduction to mean sea level
Correction for horizontal alignment
Correction for slope
All the above
Answer is Right!
Answer is Wrong!
The correct answer is: All the above.
- Reduction to mean sea level is the process of converting elevations from their original position to a common reference point, which is usually mean sea level. This is done by subtracting the elevation of the original position from the elevation of mean sea level.
- Correction for horizontal alignment is the process of adjusting elevations to account for the fact that the Earth is not a perfect sphere. This is done by adding or subtracting a correction factor, which is based on the latitude of the point being measured.
- Correction for slope is the process of adjusting elevations to account for the fact that the Earth’s surface is not flat. This is done by adding or subtracting a correction factor, which is based on the slope of the surface at the point being measured.
In all of these cases, the negative sign is assigned to the correction factor. This is because the correction factor is subtracted from the original elevation, which results in a negative elevation.