Category: Survey Engineering

Convert The Whole Circle Bearing to Reduced Bearing – || Rules and Example ||

Convert Whole Circle Bearing to Reduced Bearing Rules

1. When Whole Circle Bearing(W.C.B) lies between 0° to 90°.

• Reduced Bearing(R.B) = W.C.B

2. When W.C.B lies between 90° to 180°.

• R.B = (180° – W.C.B)

3. When W.C.B lies between 180° to 270°.

• R.B = (W.C.B – 180°)

4. When Whole Circle Bearing(W.C.B) lies between 270° to 360°.

• Reduced Bearing(R.B) = (360° – W.C.B)

Example of Convert Whole Circle Bearing to Reduced Bearing

Example:

Convert the following whole circle bearing to reduced bearing(with quadrant)
a. 30°
b. 160°
c. 200°
d. 315°

Solution:

For 30°, Reduced Bearing(R.B) = 30° NE
For 160°, R.B = (180° – 160°) = 20° SE
For 200°, R.B = (200° – 180°) = 20° SW
For 315°, R.B = (360° – 315°) = 45° NW. Where, NE, SE, SW, NW is the quadrant.

Uses Of Surveying

Convert Quadrantal Bearings to Whole Circle Bearing

Numerical Example For Error Due To Wrong Measuring Scale – Survey Engineering

Numerical Example For Error Due To Wrong Measuring Scale

Following numerical example shows that how to calculate correct length and area, if errors occur due to wrong measuring scale:

Numerical Example

A surveyor measured the distance between two points marked on the plan drawn to a scale of 1cm = lm (R.F. = 1: 100) and found it to be 60m. Later he detected that he used a wrong scale of 1 cm = 50 cm (R.F. = 1: 50) for the measurement.

(a) Determine the correct length.
(b) What would be the correct area if the measured area is 70 m²?

Mathematical Solution

a. Correct length = (R.F. of the wrong scale/R.F. of the correct scale) ⨯ measured length = [(1/50)/(1/100)] ⨯ 60 = 120m.

b. Correct area = (R.F. of the wrong scale/R.F. of the correct scale)² ⨯ measured area = [(1/50)/(1/100)]² ⨯ 70 = 280 m².

7 Uses Of Surveying

7 Uses Of Surveying

Surveying may be used for the following various purpose:

1. Engineering Surveying

Engineering surveying is used for the design and construction of a new project such as road, railway, building, city, towns etc.

2. Topographical Surveying

To prepare a topographical map, which shows the hills, rivers, valleys, forest, village, towns, etc. of a country.

3. City Surveying

City surveying, which is used to locate the streets, water supply, sanitary system etc.

Cadastral surveying, which is conducted in order to produce plans of property boundaries for legal purpose.

5. Astronomic Surveying

Astronomic surveying is used to determining latitudes, longitudes, azimuths, local time etc. for the various places on the earth.

6. Geological Surveying

To prepare a geological map, which shows the information about different strata of the earth surface for the purpose of the geological studies.

7. Photogrammetric Surveying

Photogrammetric surveying is used for obtaining topographical details of large areas which are difficult to access.