Describe the plotting procedurefor the data collected using chain triangulation

Plotting Procedure for Data Collected Using Chain Triangulation

Materials:

- Plotting paper
- Ruler
- Protractor or compass
- Pencils

Procedure:

1. Establish the Baseline:

- Plot the baseline (AB) to scale on the paper.
- Mark the ends of the baseline as A and B.

2. Calculate the Lengths of the Tie Lines:

- Use the chain measurements to calculate the lengths of the tie lines (AC, BC, and BD).

3. Construct the Triangles:

- From point A, draw a line to scale to represent the length of tie line AC.
- From point B, draw a line to scale to represent the length of tie line BC.
- The intersection of these lines determines point C.
- Similarly, construct triangle BCD.

4. Plot the Lines of Sight:

- Draw a line from point A to point C to represent the line of sight AC.
- Draw a line from point B to point C to represent the line of sight BC.
- Repeat for any other lines of sight that were measured in the field.

5. Intersect the Lines of Sight:

- Intersect the lines of sight to determine the location of the unknown points (e.g., D).

6. Plot the Unknown Points:

- Mark the intersection points on the paper as the locations of the unknown points (e.g., D).

7. Check Accuracy:

- Calculate the lengths of the lines of sight in the plot and compare them to the measured lengths.
- If there are significant discrepancies, check for errors in the measurements or plotting procedure.

8. Complete the Plot:

- Connect the plotted points to form the desired network of triangles or quadrilaterals.
- Label the points and lines of sight for clarity.

Additional Notes:

- If the scale is large, it may be necessary to divide the triangulation network into smaller sections and plot them separately.
- For more complex triangulation networks, it is recommended to use a computer-aided drafting (CAD) program for plotting.
- The plotted network can be used to calculate distances, angles, and other geometric properties of the surveyed area.