Hydrographic surveys deal with the mapping of ............

The deflection angle may have any value between ............

The position of point can be fixed more accurately by ............

In tacheometrical observations, vertical staff holding is generally preferred to normal staffing, due to ............

The vertical distance above or below the datum is called ............

In a simple curve, "External distance" is the distance between ............

An instrument error in compass survey is because of ............

The fundamental principle of surveying is to work from the ............

For the locating a distant object visible from two transit stations, the method usually preferred to, is ............