Professional Activities

1. Perform the Measurement of Horizontal Distances

• How it's done: Measured using chains, tapes, or EDM (Electronic Distance Measurement) tools via total stations or GPS systems.
  
  

• Considerations:
  
  

  • Slope correction if not measuring horizontally.
    
    

  • Temperature correction for tapes.
    
    

  • Tension and sag corrections (especially with steel tapes). Sag Correction= w^2 *  L  /  24 P^2
    
    

• References:
  
  

  • Lindeburg (CERM)
    
    

  • Cuomo
    
    

  • Wolf & Brinker
    
    

  • Ghilani
    
    

2. Perform the Measurement of Angles

• Instruments used: Theodolite or total station.
  
  

• Types of angles:
  
  

  • Horizontal angle: Often used in traverses and layout.
    
    

  • Vertical angle: Used in determining elevation changes (trigonometric leveling).
    
    

• Procedure:
  
  

  • Sight two known points.
    
    

  • Record angle from instrument zero or a reference.
    
    

• References:
  
  

  • Anderson & Mikhail
    
    

  • Wolf & Brinker
    
    

  • CERM
    
    

3. Perform the Measurement of Elevations

• Two main methods:
  
  

  • Differential leveling: Uses a level and rod to measure elevation difference between points.
    
    

  • Trigonometric leveling: Uses angles and horizontal distances to calculate elevation changes.
    
    

• Key Concepts:
  
  

  • Height of Instrument (HI)
    
    

  • Back sight (BS), Fore sight (FS)
    
    

  • Elevation = HI - FS (or HI + BS if leveling up)
    
    

• References:
  
  

  • Ghilani
    
    

  • Moffitt & Bossler
    
    

  • Cuomo
    
    

  • CERM
    
    

4. Determine Potential Construction Conflicts

• Purpose: Identify where new structures might interfere with:
  
  

  • Existing utilities
    
    

  • Substructures (e.g., foundations, tunnels)
    
    

  • Right-of-way or property boundaries
    
    

• How:
  
  

  • Overlay proposed design on existing topographic survey.
    
    

  • Use GIS or field verification tools.
    
    

• References:
  
  

  • Subdivision Map Act
    
    

  • CERM
    
    

  • Surveying with Construction Applications (Kavanagh)
    
    

Topics May Include

1. Establishing Points or Alignments Using Distances and Angles

• Use: For roadway centerlines, property lines, or building layout.
  
  

• Method:
  
  

  • Set instrument over known point.
    
    

  • Measure angle and distance to new point.
    
    

• Terms:
  
  

  • Traverse, Backsight, Foresight
    
    

  • Bearing/Azimuth systems
    
    

• References:
  
  

  • Cuomo
    
    

  • Wolf & Brinker
    
    

  • Anderson & Mikhail
    
    

2. Establishing Elevations Using Trigonometric and Differential Leveling

• Trigonometric Leveling:
  
  

  • Used where differential leveling is impractical (e.g., across rivers, valleys).
    
    

  • Requires vertical angle and horizontal distance.
    
    

• Differential Leveling:
  
  

  • Preferred for high-accuracy.
    
    

  • Setup level at midpoint between two points to reduce error.
    
    

• References:
  
  

  • Ghilani
    
    

  • Moffitt & Bossler
    
    

  • Cuomo
    
    

  • CERM
    
    

3. Surveying Equipment Usage

• Common Equipment:
  
  

  • Total station: Combines EDM and theodolite.
    
    

  • Auto-level or digital level: For differential leveling.
    
    

  • Leveling rod, tripod, prism pole, GPS rover.
    
    

• Skills:
  
  

  • Set up, calibrate, and troubleshoot instruments.
    
    

  • Check for collimation and parallax errors.
    
    

• References:
  
  

  • Anderson & Mikhail
    
    

  • Ghilani
    
    

  • Kavanagh & Slattery
    
    

4. Creating and Checking Level Notes

• Field Book Entries:
  
  

  • Date, weather, crew, project
    
    

  • Station, BS, FS, HI, Elevation
    
    

  • Loop closure check to detect errors
    
    

• Types of Level Notes:
  
  

  • Height of instrument method
    
    

  • Rise and fall method
    
    

• Importance:
  
  

  • Legal documentation of field work.
    
    

  • Must be neat, error-checked, and signed.
    
    

• References:
  
  

  • Cuomo
    
    

  • CERM
    
    

  • Wolf & Brinker