Comparison between terrestrial close range photogrammetry and terrestrial laser scanning

Remote sensing has been around since the concept was first theorised by Leonardo da Vinci in 1480. Today due to advancements in technology and computing power it is now more accessible than ever to conduct a survey on a grand scale measuring millions of points in minutes using a variety of techniques. This research project aims to evaluate and compare two remote sensing techniques known as terrestrial laser scanning and photogrammetry. Surveying is an integral part of any development and as technologies advance more information is expected out of a survey. Photogrammetry and laser scanning are two technologies that are proving invaluable for fast and accurate data collection. In the author’s research an abundance of information was found on individual techniques,however very limited information was found that compared these two technologies together. This research paper is being conducted to help bridge the informational gap between the two technologies and serve as a decision making tool for surveyors to choose which technique will best suite an individual project’s needs. In order to achieve this both techniques where tested under two different scenarios- 1. Site A-Block 11 is an as built survey of a bulk excavation site surrounded by a secant pile wall. 2. Site B-The office is a building façade comprised of concrete beams/columns and glass windows. The data was then processed and compared using free open source software known as cloud compare. This study found that when done correctly both techniques have proven to be as successful as each other in the test scenarios. Ultimately, the accuracy of any measurement performed using either technique will depend greatly on a combination of correct instrument operation/technique and a firm understanding of the limitations of each technology. This project will serve as a how too guide for surveyors conducting similar remote sensing surveys and aid in the selection of technique for the project at hand