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 www.olmweb.dot.state.mn.us & gulfsci.usgs.gov

How does LiDAR work? Simultaneously Consequently 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 www.trimble.com & www.leica-geosystems.com

CK Aerial Surveys – Specifications Point density – 15 to 60 points per m2 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 www.leica-geosystems.com

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 Traditional CK Aerial Surveys Fixed Wing Horizontal accuracy 2 cm 5 – 7 cm 10+ cm Vertical accuracy 3 cm 7 – 10 cm Point density 1 every 10 – 20 m2 15 – 60 per m2 1 – 5 per m2 Conditions Weather permitting Clear Imagery scale N/A 1:10,000 Pixel size 5 – 7 cm GSD Site access Required Not required Rapid deployment Yes No

www.ckas.co.za info@ckas.co.za +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.