Surveying is a methodology of obtaining precise geo-spatial information about the location of an object or about the distance between multiple objects. Surveying with a drone simply means that this information is collected by a drone, while it is flying over a particular area. Both traditional and drone surveying are essential for the development of GIS, but drone surveying specifically offers huge advancements in this field. There are three reasons for that:

• Drones acquire data from vantage points inaccessible to humans
• They do it at a fraction of the time, without sacrificing accuracy of measurement
• They easily and safely access hazardous or difficult-to-reach locations 

To sum up, drone surveying provides a wider scope of high-quality data with no risk to their human operators and at a reduced time and cost.

What is drone surveying used for?

Drones can be equipped with a variety of data sensors and surveying software, depending on the purpose of the surveying project. Below, we’ll give you an idea of what’s possible. 

Land management with orthomosaic photography

Drone surveying greatly accelerates and simplifies collection of topographic (land surface) data used for creating 2Dmaps. The maps are stitched together from hundreds or even thousands of high-resolution photos of an area. Here is how this process works:

• The photos are taken in a way that they overlap, making the same point on the ground clearly visible in multiple photos and from different vantage points
• All photos are corrected for image distortion, producing so-called orthomosaic images
• The orthomosaic images go through post-processing, where they are stitched together along their overlapping edges using a photogrammetry software, producing a high-quality detailed map of the desired area 

Images captured by a drone and orthomosaic maps serve as the basis for land subdivision, urban planning, and construction development. For instance, a proposed city plan or road trajectory can be overlaid over an aerial image.

Slope monitoring with digital surface modelling

In addition to 2D orthomosaic maps, drone surveying can be used for 3D digital surface modelling (DSM), providing information on the altitude of the surveyed area. With automated GIS analysis, it is possible to extract information on the steepness of the terrain, which can be later used to apply appropriate slope classification to the area and introduce necessary slope monitoring practices, including landslide mitigation and prevention. 

Wildlife population monitoring with thermal mapping

Mounting a thermal vision camera on a drone can help you identify targets with abnormal heat signatures, which has many practical applications, such as surveillance, rescue operations, assessment of building insulation quality, and monitoring for energy leaks. 

In the aftermath of Australian bushfires, scientists found one more use for thermal surveying - koala spotting. Monitoring koala population in the wild has always been a tricky and time-consuming task, with researchers spending up to 43 hours scouting the bushland before finding any evidence of a single koala present in the proximity. Implementation of drones has proven to be much more efficient than traditional approaches, with thermal surveying software successfully identifying koalas every 2 hours. This means that with the help of drones it may be possible for the first time to accurately estimate the population of koalas and other endangered species in Australia, informing efforts targeting their preservation.

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Now we have covered everything you need to move on to the next stages of your vertual work experience. But before that, let's quickly check your understanding of the relevant background...