By: Gabriel Rodríguez Rojas
What is surveying?
Surveying is a technique that determines the terrestrial or three-dimensional positions of elements. Using the information from surveying efforts allows measuring lengths, angles, and making predictions toward building models, river canalization, or city planning. Traditional methods involve the use of a positioning system and a measurement tool. But, during the time, the discipline expanded to use aerial imagery that adds context, perspective, and value to the surveying efforts. From an engineering standpoint, capturing this information allows specific assessments to be made regarding the planning, design, and execution of a project.
Aerial Surveying Methods in Engineering
Aerial surveying can have multiple components when it comes to the engineering discipline. Some of its features embark on the use of photographs to establish comparisons between a specific timeframe. For example, capturing a series of images of a bridge before, during, and after a heavy rain event to identify the extent of affected areas of the bridge and surrounding areas. This is done without the need for an operator to approach a possible hazardous bridge. Other applications utilize specific angles of imagery to create a three-dimensional (3D) representation of an area of interest. An example of this is creating Digital Surface Models (DSM) that can be coupled with other software to manipulate a possible construction site and create multiple scenarios in the design phase of a project.
What are some considerations for Aerial Surveying Methods?
The utilization of aerial surveying for capturing images should foresee the extent of the area of interest. This being that, when the area is large, traditional imagery methods (airplanes or helicopters) might be the best fit to capture such imagery. Using this method allows the images to cover a larger extent area because of the higher flight altitude of the aircraft. In contrast, when the area is smaller, newer methods such as Unmanned Aerial Vehicles (Drones) would be more suitable for the occasion. The easy manipulation and deployment of these systems allow small-scale projects to be more cost-effective and provide better detail of the information captured.
What technique is best for capturing bridge information?
When using the above example of capturing images of a bridge, a drone would be the best fit for the surveying effort. This being that the drone flight pattern and the camera angle can be easily manipulated to capture the areas of interest. With the features mentioned, the images can be focused on the affected areas, such as identifying damages in the structure or contextual images showing any changes in the structure’s integrity. The advantages mentioned give the drone platform the best fit for capturing images of a bridge in a surveying mission for engineering purposes.
Drones in digital 3D engineering models
When creating a 3D model in a surveying effort, the obvious advantage relies on using a drone platform to capture the images. The capacity of close, detailed, and specific orientation of the images allow the photogrammetric approach to be better with unmanned aerial systems. When capturing the images for this particular purpose, it is essential to cover the entirety of the structure and have an overlap between the images and different angles of the same areas. This facilitates the photogrammetric algorithms to better stitch the images during the creation of the model, as well as better accuracy for measurements.
Considering the examples above, surveying for engineering has been evolving from the use of specific tools in a terrestrial environment into novel aerial technology that expands the uses of surveying purposes. Please schedule an appointment with us for any questions regarding the use of aerial surveying for engineering purposes.
Gabriel Rodriguez Rojas supports the company with an interdisciplinary role. Some of his key roles include the permaculture design, geographical analysis and visualization, drone aerial documentation, assisting in environmental studies, writing technical documents and articles, and translation support. He has a Master’s degree in GIS & Remote Sensing and has been working in the environmental Sector since 2014.