COMPETITOR OR COMPANION TO LASER SCANNING?

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1 PHOTOGRAMMETRY: COMPETITOR OR COMPANION TO LASER SCANNING? Eugene Liscio, P. Eng., President AI2-3D David Boardman, CEO of URC Ventures Carlos Gregory Velazquez, CEO of Epic Scan Ltd. Sponsored by

2 TABLE OF CONTENTS Introduction... 3 A History of Photogrammetry... 3 The Evolution of Photogrammetry... 3 Early exploration of photogrammetry... 3 Plane table photogrammetry... 4 Analog photography... 4 Analytical photogrammetry... 5 Digital photogrammetry... 5 Quoted Targets... 6 Dense Stereo Reconstruction... 6 Photogrammetry and forgery detection... 7 Photogrammetry today... 9 Applications of Photogrammetry in Forensics... 9 Microscopic Imaging Footprint Documentation Surface Changes Tire treads Roadway defects Clandestine graves Suspect type Bullet trajectory documentation Vehicle remodeling Crime scene modeling

3 Roadway documentation Conclusion Emerging Photogrammetry Techniques Company Profile: URC Ventures Rapid 3D Processing Techniques Recreating the Himalayas Recreating Mount Hood Recreating the Salmon Creek Dam Emerging Technologies SenseFly Unit Mobile Devices Conclusion Comparing Photogrammetry, Terrestrial Lidar and GPS Evaluating Stockyards Data Collection One Project, Three Technologies GPS Terrestrial Lidar Photogrammetry Conclusion The Future of Photogrammetry and Laser Scanning Contributors

4 INTRODUCTION Photogrammetry is not a new science; in fact it has been used as long as there has been photography. However, in the last five years, processor speeds have increased and new algorithms have been written and employed in new software packages that are moving the science of photogrammetry forward. As a result, highly dense point clouds are being created using only photographs. Tens of thousands of photos can be turned into multibillion-point point clouds. But what are the accuracy of those point clouds and how should they be used? How does photogrammetry compare to laser scanning and when is it preferable to use one over the other? This report examines: The history of photogrammetry How it is currently used in forensics, construction and scientific research Emerging techniques How it compares to lidar Its future A HISTORY OF PHOTOGRAMMETRY THE EVOLUTION OF PHOTOGRAMMETRY Early exploration of photogrammetry Photogrammetry has traditionally been used to evaluate terrestrial information in aerial surveying, but it also effective for use with smaller items. Photogrammetry has gained attention recently with a surge of online products that allow users to quickly and easily create dense point clouds. But elements of photogrammetry have been in existence for centuries. Some of the initial principles of photogrammetry were established by Leonardo da Vinci who studied optical projection in the fifteenth century. 3

5 Figure 1 Plane table photogrammetry Photogrammetry has gone through several evolutionary periods. Plane table photogrammetry was prevalent from 1850 to In this era, people took images of objects and drew perspective lines to try to calculate information such as distance and other data. In 1849, Amie Laussedat pioneered some of the initial photogrammetry techniques and methods for terrestrial and aerial mapping. He started with kite photography then moved to balloon photography to make topographic maps. Amie Laussedat is often considered the father of photogrammetry. Many of his methods and techniques are still in use today. Analog photography From 1900 to 1960 the world saw rapid developments in aviation, mostly as the result of two world wars that occurred during that period. These developments impacted aerial photogrammetry. Growth in other areas of technology also occurred during this time, particularly with film cameras. Film allowed people to compare images to one another, which eventually lead to the development of analytical photogrammetry. 4