📐 TOTAL STATION BACK SIGHT (BS)

🔹 Definition: Back Sight (BS) is a measurement taken to a known control point to establish the survey reference after setting up the total station.

🔹 Importance:

✅ Establishes instrument orientation.
✅ Transfers known coordinates or elevation (RL).
✅ Improves surveying accuracy.

🔹 Procedure:

1. Set up, center, and level the total station.
2. Aim at a known control point.
3. Sight the prism and take the BS reading.
4. Record the data and continue surveying.

🔹 Key Tips:

• Use a stable, visible control point.
• Ensure accurate centering and leveling.
• Recheck the BS if the instrument setup changes.

📌 Remember: A correct BS is essential for accurate surveying results.

@ETCONP