Collecting Survey Data

 

Go to the area to be surveyed and take a look around.  After gaining a basic understanding of the area choose a route that will be taken.  This should be in the form of a polygon, or many polygons with connected sides.  Figure 1 shows a simple polygon route to be taken.  Once the first point is decided upon, go there and measure the distance to from there to the second point.  While at the first point record the angle between the line to the second point and magnetic north, this is known as the forward bearing.  Finally record the degree of inclination or declination to the next point.  After these first series of measurements are made, go to the second point and collect the same measurements to the third point.  While at the second point also measure the angle between north and the first point, this will be used later as a check and is the corresponding backward bearing to the first forward bearing.  Continue in this manner until you return to the point that you started at.  Note the dashed line in figure 1, in the event that another point is visible which is not the next or previous point, a bearing should be taken and used as a later check, though a distance measurement is not necessary.  Table 1 shows an example of the measurements to be made.

 

Table 1

Figure 1

From

Station:

To Station:

Distance (m)

Inclination (degrees)

Forward Bearing

Backward

Bearing

A

B

1350

5

33

212

B

C

500

-2

88

271

C

D

264

0

175

4

D

A

1264

8

143

36