Contour & Cross Sectional Report

CONTENT No | Title | Pages | 1 | Contents | 1 | 2 | Details of Practical | | | 3. Objectives | | | 4. Theory & Principles | | | 5. Equipment and Functions | | | 6. Task of team members | | | 7. Precautions of Practical | | 3 | Data | | | a. Sketches | | | b. Booking | | | c. Calculation | | 4 | Results | | | a. Results analysis | | | b. Value/Photo | | | c. A3 Plan | | 5 | Discussions / Conclusions / Suggestions | | | a. Question and Answer | | | b. Conclusion | | | c. Suggestion and improvements | | 6 | Appendix / References | | | a. Original Documentation | | | b. Reference | |

Objectives 1. To carry out longitudinal section (Profile) and cross section. 2. To perform the contour field work using grid method. 3. To learn about the equipment of leveling clearly 4. To document the data and produce the report.

Theory & Principles
The purpose of levelling is to obtain measurements of differences in elevation of objects that are not vertically above each other.
The level is an optical instrument that provides a height reference. This reference is a horizontal plane through the axis of the telescope, known as the "Height of Collimation".
Once the height of collimation (or instrument height) has been measured the height of other stations can be found by measuring from this plane with a staff.
The height of collimation is found by taking a backsight to a staff placed on a bench mark. The staff reading is added to the bench mark value to obtain the height of collimation.
Once the height of collimation has been found ground height at any spot below this plane can be found by observing the staff and subtracting the staff reading from the height of collimation.
Hence, the formula used in this practical is,
For each station, HPC = (known RL) + BS, and each RL = HPC – (IS or FS)
HPC = High of Plane of