LiDAR Mapping Case Study

Introduction

The scope of this project was to map a road corridor which includes Earth works, highways, Road markings, Vehicle restraint systems, Fencing, Drainage, Traffic signs, Structures, Utilities etc, using mobile and aerial lidar point cloud.

Key features

  • Automatic classification of lidar point cloud.
  • Data clean up and topology
  • Breaklines digitized using classified lidar point cloud
  • Validation and manual editing of automatic classified data.

Methodology

  • LiDAR Point Cloud Classification
    Ground surface model was created and was manually validated and edited to get proper ground surface classification.
  • Feature Extraction
  • Proposed breaklines were digitized using ground surface model or intensity mode of lidar point cloud.
  • Ground level breaklines were draped on ground surface to get 3D elevation.
  • Elevated breakline features were captured using cross sectional view, which automatically will have 3D elevation.
  • Off-highway breakline features such as slopes, fencing, drainage, embankments, water bodies, were captured using aerial lidar data.
  • Both mobile and aerial lidar data mapping feature were integrated, checked for any edge match issue.
  • Data cleanup and topology checks were done on the entire data.

Quality Assurance

A process guidelines document was prepared. Expertise with stringent knowledge in mapping helps in the final round of quality analysis. A random sample was analyzed to make sure the data was within the acceptance criterion.

Deliverables

Vector map in DGN/DWG format

Technology Used

Microstation, Terrascan, Terramodel

Inputs

  • Lidar point cloud in LAS format
  • PTC file
  • Project file
  • AOI
  • Specification document
  • Ortho imagery to aid interpretation

Application

  • Route assessment
  • Urban planning
  • Transportation planning
  • Construction of new highway
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