Surveying and Mapping

Aerial Surveying

An aerial survey is a method which involves collecting geomatics or other imagery by using a variety of methods including airplanes, helicopters, UAVs or drones, balloons and others.

Aerial survey companies typically collect data through aerial photography, LiDAR, remote sensing, and various geophysical data, amidst others.

It is imperative to know that aerial survey is distinguished from satellite imagery technologies as it has superior resolution, quality, and atmospheric conditions. Aerial surveys in Africa are often referred to as a synonym for aero photogrammetry, which is a part of photogrammetry involving a camera placed in the air.

There are several aerial survey companies in South Africa that make use of a variety of methods and technology to collect data. However, with the advancements that have been made in drone technologies, more survey companies are employing aerial survey drones.

 

Aerial survey drones have a multitude of functions and one major use is that in geomorphology, which involves an environmental assessment, which is the most common application thereof, especially in the areas of:

  • Landslide prediction
  • Earthquake prediction
  • Volcanic activity monitoring
  • Coastal deformation

 

There are numerous benefits attributed to using aerial survey drones, including, but not limited to:

  • Cost-effective
  • Improved quality of images as well as data collection
  • Reduction in field time
  • Provision of accurate and exhaustive data
  • The ability to survey otherwise inaccessible areas

 

Aerial survey companies in South Africa along with other GIS professionals have realised the potential that aerial survey drones have, along with the variety of uses that they can be employed for.

Land surveying and Cartography

Survey drones can generate high-resolution orthomosaics along with detailed 3D models of areas where there is low-quality data, data that is outdated, and areas where there is no data available.

As they capture data from above, drones have seamlessly been integrated into surveying, providing the industry with endless opportunities to make use of all that drones effort, at a lower cost than appointing survey and mapping crews.

 

Land management and development

The aerial images that are taken by drones accelerate as well as simplify topographic surveys for both land management as well as planning.

Land developers can benefit from the use of drones with:

  • Improvements in the accuracy of site surveys.
  • The ability to facilitate improved project modelling as well as forecasting.
  • Impact and inform markets, site, and terrain research purposes.
  • Increasing the efficiencies of construction and development processes.
  • Aiding in post-construction and development asset management.

 

When making use of drones, aerial surveys which are conducted with drone technology provide a wider view in addition to a unique perspective. In addition, it also helps during and after project completion.

 

Precise measurements

Surveyors can conduct a drone survey in South Africa to perform highly accurate distance and surface measurements by making use of high-resolution orthophotos produced by aerial survey drones.

 

Slope Monitoring

When using automated GIS analysis, it is possible for slope measurements to be extracted from DTMs and DSMs which are generated by imagery in a drone survey. By knowing what the steepness of the ground’s surface is, the areas can be classified and subsequently used for slope monitoring purposes.

Urban planning

With the use of a survey drone, urban planners can conduct an aerial survey in South Africa, allowing them to collect significant amounts of real-time data in a shorter time frame with far less staff. Images produced by these drones allow planners to examine existing social and environmental conditions of sites and consider the impact of various scenarios.

Some of the benefits attributed to using drones in urban planning include:

  • The ability to do automated mapping.
  • Cadastral surveying can be done with ease.
  • The ability to conduct corridor surveys
  • Volumetric calculations can be done easily once the site has been mapped with a drone.
  • The ability to create a virtual high-resolution map of surrounding areas with LiDAR.

 

Drone Mapping

The simplest definition of mapping is that it is a graphical representation of information which is based on spatial relationships. Mapping is typically used to show scaled geographical features such as forests, roads, and water.

Due to regular changes that occur as result of climate conditions and structural developments, it is necessary to carry out regular mapping.

Originally, mapping consisted of field measures; however, it evolved and started including the use of airplanes followed by helicopters with developments in aerial photography, which significantly increased mapping possibilities.

More recently, the concept of drone mapping as well as drone 3D mapping is showing a substantial increase in popularity. As with other drones, a mapping drone is an unmanned aircraft which can navigate either manually, or autonomously, and where aerial mapping is involved, an aerial mapping drone is the perfect tool for the job.

Drone mapping in South Africa can be done by a professional company that offers its services and it can be used for a variety of purposes including, but not limited to:

  • 3D drone mapping
  • Drone Golf course mapping
  • Agricultural drone mapping
  • Construction drones that inspect, survey, plot boundaries, create legally acceptable subdivisions, and map construction sites.
  • Mining drones used in mining operation to survey, plot, and map areas. Drones in mining have a plethora of benefits in optimizing site development, monitoring the environment, and efficiently engineering blasts, amidst others.

 

Although the adoption of drones in mapping is not widespread yet, mapping drones have proven to play an important part as they allow for multiple variables to be viewed simultaneously. Mapping drones also have the following benefits:

  • They save time
  • They are environmentally friendly
  • They minimise any upfront costs
  • They lower long term expenses

 

Frequently Asked Question

The cost involved with drone mapping will depend on several factors including:

  • Travel surcharges
  • Insurance coverage
  • Industry
  • Deliverables and quality
  • Level of expertise
  • Pricing per acre
  • Market value and ROI, and several others.

They are highly accurate but depend on the camera specifications, the number of photos that are collected, photo overlap percentage, flight altitude, atmospheric conditions, GPS signal strength, and the ground sampling distance, or GSD.

This depends on relative and absolute accuracy. Where small areas and simple use cases are relevant, relative accuracy is quite high with a drone. However, absolute accuracy will be determined by the overall quality associated with photogrammetric processes as well as the accuracy of the Ground Control Points.

Yes, they are. Drones are equipped with GPS modules which allows for the drone to know its location relative to a network of orbiting satellites. When drones connect to these satellites, they can hold their position, fly autonomously, return home, and navigate waypoints.

Drones are used to survey the following:

  • Land development sites to provide comprehensive recordings of real estate or property.
  • Urban land management sites.
  • Construction sites as well as earthworks.
  • Mines and quarries.
  • Archaeological sites.

No. Even though drones are useful and have many uses and advantages, they cannot replace human surveyors.

This will depend on the make and model of the drone. Some drones can only cover a small area while others can cover 160 hectares and more.