Geodetic Engineering Overview

Geodetic Engineering Overview

• Geodetic Engineering involves collecting and measuring spatial data using technology and scientific methods to create maps, plans, and spatial information systems.
• Key functions include establishing geodetic control networks, data collection and analysis, developing surveying standards, and conducting research.

Types of Surveying Works

• Geodetic Surveying:
  • Considers the earth's shape (geoid-spheroidal) for high-precision measurements over large areas.
• Plane Surveying:
  • Assumes a flat plane, disregarding earth's curvature for smaller and less precise surveys.

Classification of Land Surveys

• Control Surveys:
  • Determine horizontal and vertical positions for geodetic networks. Includes Geodetic Control Surveys and Project Control Surveys.
• Cadastral Surveys:
  • Define the boundaries of land parcels within municipalities for registration.
• Isolated Surveys:
  • For smaller land parcels (≤1,500 hectares) used for various purposes like agriculture and residential layouts.

Horizontal Distance Measurement

• Horizontal distance is the measurement between two points at equal elevation.
• Common error in measurements necessitates correction methods.
• Methods include pacing, taping, stadia measurements, and electronic distance measurements (EDM).
• A synchronous online meeting on Horizontal Distance Measurements is scheduled for August 28, 2020.

Corrections in Taping

• Taping Method:
  • Simple distance measurement using graduated tape.
• Correction Rules:
  • Tape too long: add correction; tape too short: subtract correction.
• Temperature affects measurements; use the formula for temperature correction ( Ct = C (To - Ts) l ) to adjust measurements based on thermal expansion.

Temperature Corrections

• Coefficient of Thermal Expansion:
  • ( C = 0.0000116/oC )
• Example Calculation: A 30 m long steel tape found to be 340.25 m at 35°C requires corrections to determine accurate measurements for both the tape length and the measured line.

Example Problems

• Compute Corrections:
  • Given temperature and measured line, apply the thermal expansion coefficient to calculate corrections.
• Correct Lengths:
  • Adjust the tape length and the measured line length after applying corrections.

Practical Applications

• Conduct fieldwork to gather data on pacing factors and measuring tape usage, documenting conditions and units used.
• Perform calculations for temperature corrections and create presentations based on fieldwork findings.

Important Formulas

• Relative Precision Calculation:
  • Use the formula ( \text{Relative Precision} = \frac{\text{Tape Distance}}{60} ) for comparisons.
• Temperature Corrections:
  • ( Ct = C (To - Ts) L ) for measured line corrections.

This summary provides a comprehensive look at the essentials of Geodetic Engineering and surveying practices, relevant calculations, and methodologies.

This quiz focuses on the principles and significance of Geodetic Engineering. You will explore various types of surveying works and understand the vital role of this engineering profession. It's an essential resource for students and professionals in the field.