Author: Ibrahim

The apparent change in the position of an object due to a change in the eye position of the observer is called parallax. In a telescope, parallax occurs when the image formed by the objective does not lie in the plane of the crosshairs. Unless parallax is removed, accurate bisection and objects become difficult to…

The vertical axis of the instrument is made truly vertical by a leveling-up operation which can be completed according to the following steps. a three-foot screw arrangement of a dumpy level and show a four-foot screw arrangement of a dumpy level. The telescope axis is placed parallel to the line joining one pair of screws…

This operation also involves fixing the instrument on a tripod and approximately leveling the instrument by adjusting the legs. The configuration can be completed according to the following steps. Step 1 The tripod is unfolded and set on the ground by placing it under the metal spiked legs so that it is straight and firm…

The adjustments that are made for each setting of the leveling instrument are called temporary adjustments. These include the following: Setting the levelequalizeElimination of parallax

A level requires two types of adjustments, namely, Temporary adjustmentConstant adjustment

Survey work is mainly divided into two parts: (1) field work and (2) office work. In the field, necessary adjustments are made and the results are systematically recorded as described below.

A horizontal plane: A horizontal plane through a point is a plane that is tangent to the surface of the surface at that point.Horizontal Line: A horizontal line is any line lying in a horizontal plane.Vertical Line: A vertical line at any point is a line normal to the surface through that point.Elevation: The elevation…

Line of collimation or principal line of sight: It is the imaginary straight line joining the optical center of the objective glass with the point of intersection of the crosshairs of the diaphragm.Bubble tube axis: It is an imaginary line on the longitudinal curve at the midpoint of the tube. It is also called bubble…

With self-reading staff, readings can be taken faster than with target staff.In the case of target staff, the services of trained personnel are essential.Reading can be more sophisticated with target staff. But if the crewman does not direct the line of sight correctly to bisect the target, it gives a much clearer reading. The surveyor…

Care should be taken to keep the leveling staff truly vertical during the reading. To hold the staff in a vertical position, the person holding the staff should stand with their heels behind the staff, the heel of the staff between their feet, and hold it in their hands at face height. When the level…