Compass surveying, Civil Engineering

Assignment Help:

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.


Related Discussions:- Compass surveying

Show the grout curtain around excavation, Q. Show the Grout curtain around ...

Q. Show the Grout curtain around excavation? When excavation work is performed in grounds with highly permeable soils, other than installation of well points to lower down grou

Minimisation of differential settlement, Minimisation of Differential Settl...

Minimisation of Differential Settlement You are aware that differential settlement causes more distress to the structure, when compared with that of total settlement. The var

Define project scheduling - types of methods, Define Project Scheduling - T...

Define Project Scheduling - Types of Methods Project Scheduling - Distinction between the Major Types of Schedule Diagrams Precedence Diagrams (PDM)   a) Activ

Solid mensuration, Ask question #MiniThe base of an isosceles triangle and ...

Ask question #MiniThe base of an isosceles triangle and the altitude drawn from one of the congruent sides are equal to 18cm and 15cm, respectively. Find the lengths of the sides o

Corrosion, Distinguish between dry and wet corrosion

Distinguish between dry and wet corrosion

Explain the createthread function used in the windows nt, Explain the Creat...

Explain the CreateThread Function used in the Windows NT CreateThread(security, size, MyThreadFunction, arg, flag,&tID ) The CreateThread function call is used to start an i

Write short notes on abrasion test, Q. Write short notes on Abrasion Test? ...

Q. Write short notes on Abrasion Test? The abrasion test for ballast shall be carried out using Los-Angeles machine.The abrasive charge shall consist of 12 nos. cast iron or s

Designing of service reservoirs, Question In designing of service res...

Question In designing of service reservoirs , straight reinforcement in walls of reservoirs is placed at external layer. Give some specific and main reasons?   Answer

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd