Aerial Imaging & Digital Modeling

Photogrammatery and Light Detection and Ranging (LiDAR) are two technologies that are rapidly improving in recent times, and it is no surprise to see professionals combining them with Unmanned Aerial Systems (UAS), in order to collect data over large spaces in a relatively short amount of time.

Aerial Images and Digital Surface Models (DSM) are just 2 of the outputs that Aerial Photogrammetry and LiDAR can bring to the plate, and they have proven to be very useful for a variety of applications. To name a few, these data can be employed for boundary & topographical surveys, site planning, agricultural health, terrain analysis, simulation of water flow, geological studies etc. Simply, with such extensive information taken from a bird's eye view, the possibilities for the combination of the UAS and Photogrammetry/LiDAR, is endless. 

Aerial Imaging, or Aerial Photography, refers to the taking of photos from an elevated position, like a bird's eye view or direct-down. At Aries Geomatics, we obtain such data by the use of drones, which you can read about more over here. Such images, photos or orthophotos can enable professionals to observe the said area in a clear and concise manner, thanks to the High Definition Camera on board the UAV.

IMAGE BY CARIBBEAN HANDBOOK ON RISK INFORMATION MANAGEMENT (CHARIM)

IMAGE BY CARIBBEAN HANDBOOK ON RISK INFORMATION MANAGEMENT (CHARIM)

Digital Models, on the other hand, refers to the models that take into account details such as elevation, terrain features, and above-ground features like trees, houses and vegetation. The level of detail depends very much on the type of Digital Model requested. There are 2 main types of Digital Models that we usually work with, and they are the Digital Terrain Model (DTM) and the Digital Surface Model (DSM). The 3 models differ as follows:


illustration of difference between dsm & dtm

illustration of difference between dsm & dtm

Digital Terrain Model (DTM): A 3D digital model representing the terrain's surface, with details such as the contours, rivers, breaklines and elevation, but without other non-ground objects such as vegetation and buildings. In short, it is an elevation surface representing the bare earth referenced to a common vertical datum. This model is useful for many uses, including extracting terrain parameters, creation of maps and terrain analysis for geography.

Digital Surface Model (DSM): A 3D digital model with the details of the DEM, but inclusive of all objects on it, such as trees and buildings. In short, it is a model that represents the earth's surface, inclusive of all objects on it, which reflects the highest elevation point at any given location. The DSM is good for 3D Modeling, agricultural purposes, vegetation management, and urban planning, to name a few.

The combination of the UAS and the Photogrammatery/LiDAR technology allows for endless possibilities in the field of Aerial Imaging & Digital Modeling, which we would not be able to cover here. The above is just a glimpse of what they can provide, and if you would like to know more about how they can help with your scope of work, do feel free to contact us and we will be happy to help!

Next Section: Other Applications