Compass surveying, Civil Engineering

Compass Surveying:

You have studied about the compass and its use for bearings of measuring survey lines. The angular measurements are carried out with prismatic compass that uses a magnetic needle and the bearings of survey lines are measured with reference to magnetic meridian. Such bearings are called magnetic bearings. However, on earth the true north (geographical north) is different from magnetic north. The difference between true N-S axis and magnetic N-S axis is called declination. This declination varies from place to place on surface of earth and also on time of observation. Hence, the correct measurements of angles would be to obtain bearing of survey lines with reference to true N-S axis. Such bearings are termed as true bearings. However, true bearing can only be made with the help of astronomical surveying which is tedious, time consuming and costly for engineering applications. Magnetic bearings which can be obtained easily at much reduced cost with the help of simple instruments like magnetic compass are considered accurate enough for survey of small areas.

Procedures of making angular measurements, the errors involved and method of corrections are also discussed in detail. You can now conduct a simple chain and compass survey of the area, which is fast and sufficiently accurate method of surveying for most of the engineering applications.

Posted Date: 1/24/2013 1:30:23 AM | Location : United States







Related Discussions:- Compass surveying, Assignment Help, Ask Question on Compass surveying, Get Answer, Expert's Help, Compass surveying Discussions

Write discussion on Compass surveying
Your posts are moderated
Related Questions
Cross-section of exogeneous tree

Define the Reservoirs - Hydraulic System Typically designed for multiple functions - clean water supply, creating recreational opportunities and flood protection. Reservoirs ar

describe setting out right angle at given point on a chain line and when the point lies outside the chain line

Steps to determine the hydraulic horsepower (whp) for pump problems:  1) Determine (h A ) by rearranging the Bernoulli equation.    2) Apply (h A ) into the equation found i

Q. Design a water supply scheme for new Railway colony based on the following data's. i. Requirement of Loco and domestic consumption 5 lacs gallon per day. ii. Source of wat

cooke''s reversable level

I have building 50 m * 53 m 3 floors without expansion joint in basement what are opinion please ? thanks

how to do soling for road

IS CODES FOR BUILDING DESIGN The codes which help engineers to design buildings are following: 1. IS 456-2000. For the design of plain and reinforced concrete it is code

How to read verniers and main scale readings on theodolite of 10"?