lidar introduction

LiDAR Introduction

LiDAR = Light Detection and Ranging

Airborne laser scanning – rapid high-density survey of Earth’s surface

Accurate and reliable surveys, faster and with higher density than conventional surveys

How does LiDAR work?Simultaneously

• Measure trajectory of aircraft in three dimensions• Measure orientation of laser scanner

about three rotations axes• Transmit and receive laser pulses,

measure the time-of-flight (i.e. range to reflecting surface)

Consequently• Know the coordinates of 150,000 points

surveyed per second• Map the surface of the Earth in high

density

CK Aerial Surveys – InfrastructureAS350 ‘Squirrel’

Leica LiDAR & Camera

CK Aerial Surveys – Specifications

Point density – 15 to 60 points per m2

Vertical accuracy – 7 to 10 cmHorizontal accuracy – 5 to 7 cm in both the

along- and across-track componentsImagery scale – 1:10,000Pixel ground separation distance – 5 to 7 cmResult formats – CAD designs, GIS shape files,

GeoTIFF images

CK Aerial Surveys – Products

Laser point cloud

CK Aerial Surveys – Products

Contours

CK Aerial Surveys – Products

High-resolution aerial photography

CK Aerial Surveys – Products

Power line mapping

CK Aerial Surveys – Products

Flood plain mapping

CK Aerial Surveys – Products

Volumetric calculations for mining applicationsRepeat surface survey – compare surfaces –

accurately calculate volume of removed ore

Survey ComparisonTechnique Traditional CK Aerial Surveys Fixed Wing

Horizontal accuracy 2 cm 5 – 7 cm 10+ cm

Vertical accuracy 3 cm 7 – 10 cm 10+ cm

Point density 1 every 10 – 20 m2 15 – 60 per m2 1 – 5 per m2

Conditions Weather permitting Weather permitting Clear

Imagery scale N/A 1:10,000 1:10,000

Pixel size N/A 5 – 7 cm GSD 5 – 7 cm GSD

Site access Required Not required Not required

Rapid deployment Yes Yes No

www.ckas.co.zainfo@ckas.co.za+27 11 949 8904

Executive SummaryAerial laser scanning is rapidly becoming the preferred surveying technique. Its high-resolution and rapid results, which are accurate enough for the most construction and mining applications, make aerial laser scanning (or LiDAR) the surveying technology of choice for a changing environment. Combined with geo-referenced high-resolution imagery, the spatial dataset becomes even more intuitive to decision makers and engineers alike.