How to incorporate drone data to manage your projects

Photogrammetry refers to the science of making measurements from photographs. In the drone mapping process, the input is usually an aerial photograph that fetches an output in the form of a map with measurements. A drone hovers over the designated subject to collect subject matter for inspection. Once the aerial images are acquired, they are processed and analysed for finding any common elements on a subject’s surface before creating a point cloud. Point clouds represent the X, Y, and Z geometric coordinates of a single point on an underlying sampled surface are generally used for creating 3D models, elevation maps and orthomosaic of the inspection area. 

Types of maps created during a drone survey

Point Cloud

Ever thought about what the real world would look like in the form of points? This is exactly what a point cloud depicts. Consisting of a large number of points (over a crore), it is a representation of the real world in the form of georeferenced points. Where orthomosaic maps represent just a 2D image of the Earth, the point cloud feature enables you to capture the Earth’s images in a 3D format. This feature gives you the freedom to estimate:

• The volume of a specified region
• The accurate elevation profile of a section
• The height difference between two points
• Generate 3D models

Orthomosaic Maps

Constructed out of the words Ortho (perpendicular) and mosaic (multiple small pieces joined together to create a single big piece), an orthomosaic map is a series of individual photos tallied using drone software to form new composite images that consist of all the smaller images.This is like Google Earth, but way sharper. It is a large, map-quality image with high detail and resolution. Orthomosaic maps are a reliable measure of true distance because they offer a realistic representation of the inspection area. Along with providing accurate measurements, these maps also serve the following purposes:

• Provide geometrically correct refurbished views of large inspection areas
• Understand land usage patterns in large areas
• Perform aerial inspection with higher efficiency

Digital Elevation Models (DEM)

Drone technology enables the efficient creation of elevation maps with valuable insights across industries. The construction, mining and agricultural sector use standard geo-referenced information embedded in the drone imagery for displaying elevation data. This is  a 3D representation of the terrain, which is commonly used for all altitude measurements. They can be categorised in to two types: 

Digital Surface Model (DSM) - The in-built, natural and exact features of the Earth are best captured with the help of a DSM. In terms of altitude, DSM is the digital representation of the Earth’s surface that is obtained directly using any standard photogrammetric software. Using drone analytics software DSM is used in a variety of planning, analysis, visualisation, and modelling applications, including:

• Urban planning
• Navigation systems, 
• Intelligent transport systems
• Forecasting of urban risks
• Mapping of flood risk.

Digital Terrain Model (DTM) -  It represents the bare earth topography of the area, without any  natural or man made features such as vegetation, buildings, structures, etc. It is obtained by classifying the point cloud into on the ground and above the ground areas.  DTM is useful for the following purposes:

• Mining and real estate excavations
• Estimating the volume of stockpiles 
• Drainage assessments
• Manage site progress

Contour Line Maps

Contour line maps give valuable information about the terrain. It is a topographic map on which the shape of the land surface is shown by contour lines, the relative spacing of the lines indicating the relative slope of the surface. Contour line maps have the following benefits to offer:

• Come in handy as guidelines in inspections that include hilly terrain or trees
• Decide railway, road, canal or sewer routes to minimize and balance earthworks
• Calculate the volume of stocks for the mining industries to ease out their operations

Benefits of drone mapping

Lowered survey costs and field time

Topographic data can be captured much faster with the help of a drone as compared to manual land-based methods. Less involvement of manpower and more use of technology paces up the drone mapping process. As a result, faster surveying results are generated at a much lower cost.

Precise and comprehensive data‍

A single drone flight is capable of producing thousands of measurements. These measurements can be represented in the form of contour lines, DTM, DSM, point cloud or othromosaic maps. 3D geographical data is contained in each pixel of the maps produced.

‍Surveying of otherwise inaccessible area

Manual mapping can’t reach every area that needs to be inspected. This is where aerial drone mapping comes to the rescue. Being able to take a flight almost anywhere, drones provide mapping procedures with an expansive scope of the inspection. Unreachable areas with obstacles like trees, towers, buildings, harsh terrain or steep slopes can be inspected using drone mapping technology.

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Uses of drone surveys across industries:

Mining and aggregates

Drones analytics can help monitor extraction volumes everyday, reduce material pilferage, reduce labor costs by managing the entire mine operations efficiently by:Identifying hazards 2. Planning operations 3. Estimation of volumes 3. Monitoring mines and quarries 4.Road and slope monitoring processes 5.Assessing the mine before blasting or drilling 6.Managing 

Construction and infrastructure 

Analysing drone data of the construction worksites ensure accurate reporting of subcontractors, complete projects on-time and manage the projects closely by: 

• Measuring volumes
• Construction progress tracking
• Mapping 3D models of inspection sites 

Agriculture 

Drone analytics platforms like Spectra lets one take full control of the farm by:

• Plant health monitoring
• Maintaining a plant count
• Optimizing the ROI on plants
• Assessing losses after a major weather event occurs

Renewables

Increase  turnaround of projects and ensure optimal efficiency of solar plants by performing periodic preventive maintenance inspections by using drones. This data can be used to: 

• Monitor project changes closely
• Classify inspection areas
• Identify defects

Along with these industries drone data adds tremendous value to many other industries. However, with technological advancements on the rise, companies are planning drone mapping projects on a huge scale. It becomes extremely necessary to collect high quality accurate drone data:

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Techniques to improve the accuracy of drone data:
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• Use a high-resolution camera that can fetch crystal clear individual images. A highly pixilated image contains more information and renders an increased probability of matching commonalities.
• Check the weather conditions beforehand and take a flight accordingly. Weather conditions can highly affect the image quality and the drone map’s overall accuracy. Avoid weather patterns including cloud over and high winds, whilst striving to fly when the Sun shines highest in the sky.
• Fly your drone at a lower altitude for capturing more landscape details. Not only this but flying at a lower altitude will render you with more data points to work with. With a greater number of overall images captured, you’ll have enhanced chances of meeting common points while mapping.
• Capture ground control points and essentially entail ground markets in your inspection area before taking a flight.

Skylark Drones offer an app-based service called DMO that enables drone service providers to perform multiple operations with the click of a button. Service providers can now accomplish accurate and consistent drone missions within no time. Ease out complex drone mapping surveys and missions with the tap of a button with Drone Mission Ops.