Compass Surveying
Compass Surveying, Basic difference between chain and compass surveying, Classification of Traverse- Closed Traverse, Open Traverse. Compass traverse, Meridian– True Meridian, Magnetic meridian, Grid Meridian, Arbitrary Meridian. Bearing, Types of bearing- True Bearing, Magnetic Bearing, Grid Bearing, Arbitrary Bearing. Designation of Bearing or Representation of Bearing- Whole Circle Bearing System, Quadrantal Bearing System.
Fore Bearing And Back Bearing, Relationship Between Fore Bearing And Back Bearing, Include Angle, Magnetic Declination, Type of Declination- Eastern Declination, Western Declination. Variation of Magnetic Declination- Secular Variation, Diurnal Variation, Annual Variation, Irregular Variation. Adjustments Of Angles, Angle of Dip, Local Attraction
Compass, Temporary & Permanent Adjustments Of Compass– Temporary adjustments, Permanent Adjustments. Compass are generally two types- Surveyor Compass, Temporary adjustments of a Surveyor’s Compass- Centring- Levelling. Permanent Adjustment of Surveyor’s compass, Prismatic Compass, Temporary Adjustments of a Prismatic Compass- Centring, Levelling, Focussing, Permanent adjustment of prismatic compass, Difference Between Prismatic Compass and Surveyor Compass
Topics
In plane table surveying we details discuss accessories used in plane table surveying, alidade, tripod, level tube, compass, plumbing fork, setting up the plane table: centering, levelling, orientation, method of plane table survey.
In traverse survey, latitude and departure, checks in a closed traverse, closing error, relative precision, bowditch’s rule, transit rule are details discuss.