Radial line surveys

• What is radial line surveying?

  A surveying technique for mapping and determining locations of points relative to a central position on a small scale
• Why is radial line surveying commonly used?

  It is effective for irregular or difficult areas
• What are the uses of radial line surveying?

  • Surveying irregular terrain
  • Mapping out large areas
  • Determine positions of objects
• What equipment is used for radial line surveying?

  • Theodolite for measuring horizontal and vertical angles
  • Total station combines angles and distances ( Theodolite + EDM = TS)
  • GPS for precise location data
  • Chain /+ tapes for distance measurement
  • ranging rods
  • levelling staff
• What are the advantages of radial line surveying?

  • Quick and effective for small areas
  • lowers the need for inter point visibility
  • High accuracy with modern equipment
  • Ideal for irregular terrains or inaccessible points
• What are the disadvantages of radial line surveying?

  • Accuracy depends on the precision of instruments and measurements
  • Central station must be well defined and stable
  • errors in angle or distance measurements affect entire survey
• Permission is required from land owners by surveyors unless they are acting under a easement to avoid trespassing
• Accuracy depends on the precision of the instruments and measurements as well as the further away they are from the central station
• Set up

  1. Install a fixed, single control point as high as possible in the centre of the site with the total station / theodolite ensuring its securely fastened
  2. Evenly spread out the ranging rods across the whole site
  3. Following the set up method for the total station / theodolite each feature is then ready to be visited
  4. Record the distance with the tape measure from the feature back to the control point