Methods of locating sounding

Introduction

Sounding is the process by which depth of water bodies is measured.There are various methods adopted to employ the same.They are listed below.

1)Location by cross rope

It is very advantageous to use this method in the case of narrow rivers or water bodies. A wire with markings or a long rope with markings is stretched over the water body and the sounding is done with respect to the marked readings.

2)Location by range and time intervals

This method is adopted mainly in still water.Sounding is done from boat at regular time intervals keeping the speed of the boat constant.As the speed of the bat is constant the range at which sounding is done will also be constant.

3)Location by range and angle from the shore

For this a boat with sounding man is made to traverse along the ranging line and at angle of 90 degree from the ranging line a suitable station point is taken for setting up theodolite on the shore.

The transit man measures the horizontal angle at equal intervals and the sounding man measures the depth at same time intervals.Generally all the fifth readings are measured using the horizontal angles.The intermediate sounding points are noted with respect to time alone.        

4)Location by range and angle from the boat

In this unlike in the above mentioned method the angles are taken from the boat using a sextant.This is a better method compared to the earlier one