A 2018 market study by Skylogic Research identified the survey and mapping industry as the most profitable of all UAV business segments. Given the lucrative nature of this business many UAV professionals are looking to offer UAV survey, mapping and GIS services, however, it is not as easy as simply mounting a camera to your UAV platform and taking pictures.
First, recognize that the survey, mapping, and GIS industries support a set of requirements that tend to be unique to each applications, thus 'one configuration does not fit all!'
Start with identifying the applications that you wish to support, as this will help in identifying the UAV airframe you may want to deploy, as well as the sensor payload that you may need to support your UAV applications.
If you have a UAV, you will need to determine if it is the right airframe for your application(s). For example, you’ve decided to support corridor mapping, a market segment where there is a huge upside with the utilities, pipeline and transportation industries. Typically, you will want to use a fixed wing UAV for this application, due to the greater distance that a fixed-wing UAV can cover, as opposed to a multi-rotor UAV. A multi-rotor UAV is much more practical for small area surveys given the limited flying time (e.g. 20 to 30 minutes) that is typical with these platforms.
Here’s where things get a little more complicated, as today, there are many choices of UAV sensors that are available on the market, ranging from RGB cameras to high-quality LiDAR systems. Think of it this way – your sensor systems need to support your applications.
Let’s look at a few examples:
There is a lot more to data collection then just capturing your imagery, you also need to georeference your imagery to its correct geographic position on the ground, so that Surveyors, Mappers, or GIS Professionals can effectively use the imagery data. There are several ways to do this such as tying the imagery to a surveyed network of ground control points, however, the most efficient and cost effective method is to use a process called Direct Georeferencing. In essence, DG directly measures the position and orientation of a UAV sensor, such as a digital camera or laser scanner, thereby making it possible to assign a geographic location on Earth to a pixel from a camera or a digital point from a LiDAR, without the need for ground control points. This is accomplished by capturing both position or orientation data for your imagery using an integrated GNSS/INS, such as the Applanix APX-15 (pictured), mounted on your sensor payload or UAV airframe.
In addition to the positioning/orientation equipment on the UAV rover, you will also need a GNSS correction method. For this, you will require either a physical base station, a virtual reference station solution, or an augmentation service. An example of a low cost effective base station is the Trimble Smart Target Base Station (pictured).
The Applanix SmartBase module generates a virtual reference station from existing CORS stations, while the POSPac Post-processed Centerpoint RTX (PP-RTX) service uses Trimble high performance global RTX corrections to generate cm accuracy without local base stations.
The final step is to process the data you have collected this includes your imagery, your GNSS/IMU data from your UAV, and your GNSS correction data. This step is typically completed by post processing software, such as with the Applanix POSPac UAV software. The post-processing step results in an Exterior Orientation (EO) file or a LiDAR point cloud - typically a LAS file. These files adhere to industry standards, and can be immediately loaded into any number of product generation applications, such as UASMaster.
With your UAV platform – fixed-wing or multi-rotor, sensor payload, and Direct Georeferencing technology along with post processing software in place, you have effectively turned your UAV into a low-cost, highly efficient professional grade survey and mapping solution compatible with a range of cameras, LiDAR’s and other mapping sensors.