COMPASS SURVEY

Other Chapters

• Q1: What is the principle of compass surveying?
  Ans: Compass surveying is based on the principle of traversing. In this method, the framework consists of a series of connected lines, the lengths of which are measured using a chain or tape, and the directions are determined with a compass.
• Q2: What is the difference between traversing and triangulation?
  Ans: Traversing involves a series of connected lines forming a path, whereas triangulation divides the area into triangles to determine positions more accurately.
• Q3: Define traverse.
  Ans: Traverse is defined as a series of connected lines whose lengths and directions are measured to establish control points.
• Q4: What is open traverse?
  Ans: An open traverse consists of a series of connected lines whose starting and ending points do not meet. It is used for long, narrow surveys such as roads, railways, or river mapping.
• Q5: Define closed traverse.
  Ans: A closed traverse is one in which the starting and ending points coincide, forming a closed loop. It is useful for boundary and land surveys.
• Q6: Define fore bearing.
  Ans: Fore bearing (F.B.) is the bearing of a survey line measured from the starting point towards the endpoint.
• Q7: Define back bearing.
  Ans: Back bearing (B.B.) is the bearing of a survey line measured from the endpoint back to the starting point. The difference between the fore bearing and back bearing is always 180°.
• Q8: What is true bearing?
  Ans: True bearing is the horizontal angle measured from the true north to the line in a clockwise direction.
• Q9: What is magnetic bearing?
  Ans: Magnetic bearing is the angle measured from the magnetic north to a survey line using a magnetic compass.
• Q10: Define arbitrary bearing.
  Ans: Arbitrary bearing is an assumed bearing used when there is no reference to true or magnetic north.
• Q11: Define WCB system.
  Ans: The Whole Circle Bearing (WCB) system measures the bearing of a line in degrees clockwise from the north, ranging from 0° to 360°.
• Q12: Define quadrantal bearing system.
  Ans: The Quadrantal Bearing (QB) system measures the bearing from either the north or south towards the east or west, expressed in degrees from 0° to 90° within each quadrant.
• Q13: What is prismatic compass?
  Ans: A prismatic compass is an instrument used to measure angles and bearings. It has a prism for reading values and a magnetic needle that points north.
• Q14: Define surveyor’s compass.
  Ans: A surveyor’s compass is similar to a prismatic compass but lacks a prism. It uses a fixed needle and is divided into four quadrants for measuring angles.
• Q15: What is local attraction?
  Ans: Local attraction occurs when nearby magnetic substances disturb a compass needle, causing incorrect readings.
• Q16: What is declination?
  Ans: Declination is the angle between the true north and the magnetic north at a particular location and time.
• Q17: What is an isogonic line?
  Ans: An isogonic line is a line on a map connecting points of equal magnetic declination.
• Q18: Define meridian.
  Ans: A meridian is a reference line used in surveying to measure bearings. It can be true, magnetic, or arbitrary.
• Q19: Enlist types of meridians.
  Ans: The types of meridians are:

  • ➔True meridian
  • ➔Grid meridian
  • ➔Magnetic meridian
  • ➔Arbitrary meridian
• Q20: Define true meridian.
  Ans: The true meridian is the line passing through the geographical north and south poles and a given point on the earth’s surface.
• Q21: What is meant by magnetic meridian?
  Ans: A magnetic meridian is the direction indicated by a freely suspended magnetic needle unaffected by nearby objects.
• Q22: Define arbitrary meridian.
  Ans: An arbitrary meridian is an assumed direction chosen for convenience when surveying a small area.
• Q23: Define grid meridian.
  Ans: A grid meridian is an artificial reference meridian used for mapping, often chosen by state agencies for a specific zone.
• Q24: Define bearing of a survey line.
  Ans: The bearing of a survey line is the horizontal angle between the line and a reference meridian, measured in degrees.