Transverse survey

1
Transverse survey
Transverse or offset surveys are used to find the
area of irregular shapes, such as the field ABCDE
to the right.

• In this method the surveyor
• walks along a straight line (eg AD),
• the transverse line,
• often a diagonal of the area to be surveyed,

• measuring distances along this line and
• distances to major features, or offsets, when
  they are at RIGHT ANGLES to the transverse line.
• For example

2
Transverse survey

• To survey the field ABCDE
• Choose any suitable diagonal, ie AD
• Measure the lengths along the transverse line, ie
  AP, PQ, QR and RD.
• Measure the lengths of the offsets, ie BQ, CR and
  EP.

3
Field diagrams
When in the field doing the survey the surveyor
sketches the information as a field diagram.

• To complete a field diagram
• Start at one end of the transverse line
• Write down the cumulative distances of the
  offsets from the starting point

1. Write down the lengths of the offsets, on the
   left or right, as appropriate.
2. Units are not shown.

4
Example 1
a) Complete a field diagram for this field
40
30
28
K
22
15
I
14
20
L
b) Calculate the area of this field.
A1 ½bh ½ 20 14 140
A3 ½ 28 10 140
ATOT 140384140300 964u2
A2 ½(a b)h ½ (20 28) 16
384
A4 ½ 40 15 300
5
Example 2
Sketch the field represented by this field
diagram.
D
15
39
C

• You may also be asked to
• Make a scale drawing of the field
• Find lengths such as AB or BC.

32
35
B
29
20
E
27
A
6
Todays work
Field Diagrams Worksheet 1, 2, 3, 4
7
Field Diagram Task

• On the oval there are twoirregular fields
  marked with different coloured cones.
• Use the trundle wheels/tape measures and set
  squares to measure the offsets for the two
  irregular fields.
• Create a notebook entry for the two irregular
  fields.
• Sketch the two fields, showing all the
  appropriate measurements.
• Calculate the area perimeter of both fields.