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 conventional surveys than

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 – Infrastructure AS350 ‘Squirrel’ Leica LiDAR & Camera

CK Aerial Surveys – Specifications Point density – 15 to 60 points per m 2 Vertical accuracy – 7 to 10 cm Horizontal accuracy – 5 to 7 cm in both the along- and across-track components Imagery scale – 1:10,000 Pixel ground separation distance – 5 to 7 cm Result 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 applications Repeat surface survey – compare surfaces – accurately calculate volume of removed ore

Survey Comparison

Technique

Horizontal accuracy Vertical accuracy Point density Conditions Imagery scale Pixel size Site access Rapid deployment

Traditional

2 cm 3 cm 1 every 10 – 20 m 2

CK Aerial Surveys

5 – 7 cm 7 – 10 cm 15 – 60 per m 2

Fixed Wing

10+ cm 10+ cm 1 – 5 per m 2 Weather permitting Weather permitting Clear N/A 1:10,000 1:10,000 N/A Required Yes 5 – 7 cm GSD Not required Yes 5 – 7 cm GSD Not required No

www.ckas.co.za

[email protected]

+27 11 949 8904

Executive Summary Aerial 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.