Pit & Quarry, August 2017

DRONES MAPPING The perspective a drone provides is far removed from traditional capture methodologies as users can control the drone to fly at a certain elevation to get a certain percent overlap as well as plenty of other angles and views is that its not about one being better than the other Both technologies have their applications and they also have their limitations LiDAR is more expensive and it can be lower density than photogrammetry but what people dont understand are the conditions that need to be met for photogrammetry Neither is a tool for every job There are some obvious limitations and strengths of each technology that will drive a decision Boardman says If youre doing something in the dark youre not going to be want to take pictures You could put some lighting up and things like that but then you start to lose the benefits of the camera Then it comes down to questions of scale How big of an area are you talking about Can you collect it with one person with a LiDAR unit or do you need to send out 20 people with cameras Theres a wide array of factors that inf luence the decision of going with lasers or photos he adds Considering budgetary limitations a project might not even get off the ground if limits are pushed too far That can force someone to choose the most economically feasible option regardless of the other details Its a choice some people have to make but moving forward with a low cost solution can mean risks in terms of the quality of a given output or deliverable People need to be aware of those risks and its important to properly evaluate how the technology youre using will impact the potential success of a project The drone does not matter as long as it can fly the mapping pattern and a mechanism is in place to fire the camera at the appropriate stations to achieve proper coverage says Lewis Graham president and chief technical officer at GeoCue Corp The camera does matter If you do your homework the desired goal is achievable Starting out cheap is actually a pretty good idea for a do ityourselfer You are going to crash and destroy equipment When experimenting for themselves aggregate producers should reach out to others who have tried to solve the same problems to see the issues that emerged Buying a drone and plugging it into a low cost processing software option can be a viable option but anyone doing so should have an idea about what theyre getting as well as what they arent getting by trying to handle everything themselves Takeaways Regardless of how information is captured its not a case of choosing either photogrammetry or LiDAR because these technologies are inherently being used to do different things One good analogy Boardman offers is to consider whether you want would to have a cellphone or a laptop If given a choice most people would want both because theyre both ideal tools for different things So its always about figuring out what people are trying to do Theres no silver bullet Omans says The bottom line is that with good contrast good lighting and proper conditions photogrammetry is an excellent tool but as soon as you add vegetation or complex structures into the picture LiDAR will a lways have the upper hand Its all about the right tool for the right job Weighing those factors is important and certain situations mean photogrammetry is going to be the right choice In other instances LiDAR will be But anyone who wants to work in the industry should know about both because theyre going to need to utilize both photogrammetry and LiDAR P Q Jeremiah Karpowicz is the executive editor for Commercial UAV News S6 PIT QUaRRy August 2017 pitandquarry com