There is a TON of interest throughout the construction industry regarding drones. Drones are a great tool and a low cost way to collect topographic data. Unfortunately, all the hype makes surveying with a drone seem overwhelming, complicated and expensive. At Quantum we subscribe to the K.I.S.S system (Keep, It, Simple, Stupid!) regarding drone data collection. Read to develop an understanding of the basics of drones and data.
The most progressive contractors are moving to 3D modeling for their structural excavations, just like they use a 3D surface model to grade the rest of the project. Quantum's experts take the location and depth information from the Engineer's design to build a 3D model of the structural plans. That 3D model then guides your excavator to dig in the correct location and depth required by the plans, no more, no less. You can use your rover to stakeout locations and depth, too.
Many contractors regularly utilize single point control. It is a great way to use your GPS machine control system for small designs, stockpile calcs or even as an ad hoc laser. Unfortunately, due to the "single point" nature of the process, we have seen it cause problems that could have been avoided. If you need a refresher on how site control works, check out this blog post. It will help you understand why single point control is not used on engineered projects and why you need to be careful using it on yours.
You hired the project Engineer to place your control, you surrounded the site with points and shot in more than five control points. What could go wrong now? A lot, if you don't use some independent checks to verify that your 3D model matches up to the real world.
Setting up your machine control system requires the use of site control points. The number of them you calibrate to is important to the proper function of your GPS system. This blog post will describe how each point improves the accuracy of the system.
Let's imagine your project is drawn on a piece of paper and you have to place it on a globe. To get the paper - your project - to conform to the shape of the globe, you would need to pin down all of the edges. If you only pinned down one side or just three corners, the paper would drift away from the surface of the globe on the side opposite the pins. I may have oversimplified a little, but site control places your GPS machine control file in the real world in much the same way. To get your 3D model in the right place horizontally and vertically, you need to "pin" down the edges. A "pin" or two in the middle is...
As GPS machine control continues to become more commonly used, engineers are readily giving out digital files. Some engineers in addition to the standard CAD file are also including a surface file. Using these files has lead to some common issues during construction.