Gales Traverse Table-Definition, Procedure and Table
Traverse computations are usually done in a tabular form, a more common form being gales traverse table is shown below figure. For complete traverse computations, the following steps are usually necessary.
The procedure used for making gales traverse table
1. Adjust the interior angles to satisfy the geometrical conditions, that is sum of interior angles to be equal to (2N-4) right angles and exterior angles (2N+4) right angles.
In the case of a compass traverse, the bearings are adjusted for a local attraction
2. Starting with observed bearings of one line, calculate the bearings of all other lines. Reduce all bearings to the quadrantal system.
3.Calculate the consecutive co-ordinates ( that is latitudes and departures)
4. Calculate the ∑L and ∑D.
5. Apply necessary corrections to the latitudes and departures of the lines so that ∑L=0 and ∑D=0. The corrections may be applied either by transit rule or by compass rule depending upon the type of traverse.
6. Using the corrected consecutive coordinates, calculate the independent coordinates to the points so that they are all positive, the whole of the traverse thus lying in the northeast quadrant.
Hope you understand the procedure and steps used in gales traverse table.