The Beginners Guide To Drone Photogrammetry

Drone Photogrammetry: An Overview

Drone photogrammetry is a process that deftly merges drone technology with the art of photogrammetry. But what is this exactly, and how does it work?

Drone Deployment for Photogrammetry

Drone photogrammetry starts with deploying a drone over a specific target area. Here, the drone captures a photograph every few feet across the entire coverage area. To achieve this effectively, the use of automated software or data acquisition software is necessary (or at least, strongly recommended), which ensures the capture of high-quality, geographically accurate images.

It’s important to highlight that photogrammetry doesn’t require a drone. The drone simply serves as a medium that carries the camera used to capture the necessary photos. In the context of photogrammetry, the drone is an effective tool that brings mobility, flexibility, and a high-level perspective to the process.

The Photogrammetric Process

Photogrammetry involves an intricate process of stitching together numerous photos to create 2D and 3D models. These models are utilized for various applications, some of which are enhanced significantly by the use of drone technology.

Upon completion of the drone’s flight and capturing all necessary photos, the next step is to process these images using specific software. Once the photos are imported into the software, it extracts information such as distance, area, and elevation from the 2D images.

The Creation of Point Clouds

The software then embarks on a complex process of analyzing overlapping images to create what is known as a ‘point cloud.’ A point cloud is a dense collection of data points that defines the shape of an object, which, in this scenario, can be a piece of land, a building, or any other object the drone has flown over. This collection of data points serves to create a highly detailed and accurate representation of the photographed area, paving the way for a multitude of applications in various sectors.

This method of creating point clouds, and thus 2D and 3D models, has revolutionized fields such as mapping, surveying, and modeling, and it’s only becoming more refined as technology advances. Drone photogrammetry is a powerful tool that is reshaping the world as we know it, and its potential is vast.

Applications of 3D models from drone photogrammetry

There are already loads of specific uses of drone photogrammetry out in the wild. Even the long list below isn’t exhaustive though, and that’s because drones can be used for just about any kind of large-scale photogrammetry project and due to the technology still being in its infancy, new use cases are being found frequently:

  1. Construction and Infrastructure: In construction projects, drone photogrammetry can be used for site planning, monitoring progress, detecting changes, or identifying potential issues. It also helps in creating as-built models for infrastructure.
  2. Urban Planning: Drone-generated 3D models of cities or neighborhoods can help urban planners visualize new projects, estimate impacts, and model traffic flows.
  3. Environmental Studies: Researchers can use drone photogrammetry to create detailed 3D models of large areas of land or water bodies to study environmental changes or plan conservation efforts.
  4. Mining: In the mining industry, drone photogrammetry is used for planning, monitoring the mining process, calculating volumes, and ensuring safety.
  5. Agriculture: Farmers can use 3D models of their fields to monitor crop health, estimate yields, assess irrigation systems, and manage pests.
  6. Archaeology: Detailed 3D models of historical and archaeological sites can be created using drones, preserving the sites digitally and enabling comprehensive analysis.
  7. Real Estate: Drone photogrammetry allows for the creation of 3D property models for marketing purposes, providing potential buyers with a comprehensive view of the property.
  8. Surveying: Land surveyors can use drones to capture detailed aerial data and create precise 3D models of the terrain, which is especially useful in inaccessible areas.
  9. Disaster Management: After a natural disaster, drone photogrammetry can be used to assess the extent of damage, plan recovery efforts, and assist in reconstruction work.
  10. Forestry: Drones can generate 3D models of forests, helping in management and conservation efforts, calculating biomass, and monitoring wildlife.
  11. Insurance: For claims related to property or structural damage, 3D models created by drones can provide an objective assessment.
  12. Solar Energy Planning: 3D models of buildings or plots of land can help in planning the installation of solar panels, by estimating the sun exposure and potential output.
  13. Marine and Coastal Studies: Drones can be used to create 3D models of coastal areas, marine life, or underwater structures, aiding in studies of erosion, sea-level rise, and marine biology.
  14. Heritage Conservation: Historic buildings, monuments, and landmarks can be modeled and preserved digitally, providing valuable resources for restoration and conservation projects.
  15. Power Line Inspection: Utility companies can use drone-generated 3D models to inspect and maintain power lines, particularly in hard-to-reach areas.
  16. Cell Tower Inspection: Drone photogrammetry can assist in maintaining and inspecting communication towers, offering a safer and more efficient alternative to manual inspection.
  17. Avalanche Prevention and Safety: Drones can be used to create detailed 3D models of snow-covered mountain areas to analyze and predict avalanche risks.
  18. Wildlife Research and Conservation: Drones can provide 3D models of habitats and wildlife populations, facilitating non-invasive research and conservation efforts.
  19. Glaciology: Drone photogrammetry allows for the study of glacier movement and melting over time, contributing valuable data to climate change studies.
  20. Military Training: 3D models of landscapes and urban areas can be used to create realistic training scenarios for military and defense forces.
  21. Volcanology: Drones can safely capture data from active volcanoes, creating 3D models for research, monitoring activity, and predicting eruptions.
  22. Oil and Gas Industry: In the oil and gas sector, drone photogrammetry can help in site selection, planning of drilling operations, pipeline inspections, and safety assessments.
  23. Public Safety and Emergency Response: Drones can be used to create 3D models of incident scenes for use in tactical planning and response, as well as in training exercises.
  24. Film and Game Production: Drones can capture 3D models of locations for pre-visualizations in film production, helping directors and cinematographers in planning their shots.
  25. Event Planning: For large-scale events such as sports, concerts or festivals, 3D models can assist in planning the layout, estimating crowd flow, and organizing logistics..
  26. Golf Course Management: Golf course managers can use drone photogrammetry to create 3D models for course design, maintenance, irrigation planning, and player experience enhancement.
  27. Retail and Commercial Planning: Retailers can use 3D models of commercial spaces to plan store layouts, signage, and customer traffic patterns.
  28. Watershed Management: 3D models can help scientists understand the morphology and flow of watersheds to assist in flood prediction and water management strategies.
  29. Fisheries Management: 3D models of rivers, lakes, and marine areas can provide insights into fish habitat and spawning locations, supporting sustainable management practices.
  30. Wind Turbine Inspection: Wind farm operators can use drones to create 3D models of turbines to inspect them for any potential maintenance issues.
  31. Bridge Inspection: 3D models can be used to conduct safety inspections of bridges, reducing the risk and cost associated with manual inspections.
  32. Landfill Management: Drones can create 3D models of landfills to monitor capacity, track changes over time, and assist in planning expansion or reclamation efforts.
  33. Dam Inspection: Drones can provide safe, cost-effective means of inspecting dams, creating detailed 3D models to help identify potential structural issues or maintenance needs.

The Best Drone for Mapping

If you’re venturing into the drone industry, you’ll no doubt be wondering “Which drone should I invest in?” When exploring drones for photogrammetry and mapping, you have three main categories to select from. Let’s delve into each one to help you make an informed decision.

Beginner Drones: An Affordable Start

Drones like the DJI Mini 2 or Autel Evo Nano Plus fall into the category of beginner drones. They are cost-effective solutions that will enable you to get started with flying automated missions. While these may be categorized as ‘beginner’ drones, don’t underestimate their capabilities. They are even employed in large-scale projects. With the right skills, you can learn how to fully exploit their potential.

Advanced Drones: Higher Specifications, Enhanced Capabilities

The next tier includes advanced drones like the DJI Air 2S, Autel Evo 2 Pro, and the Skydio 2 Plus. What differentiates these drones as ‘advanced’ are their high-resolution cameras, extended flight times, and the ability to integrate with third-party applications for more complex missions.

If you’re interested in advanced drones but are working within a tight budget, you might consider exploring the second-hand market. Drones like the DJI Mavic 2 Pro and Phantom 4 Pro are also excellent choices, despite not being supported by DJI any longer. However, keep in mind that if you need accessories such as batteries and propellers, you’ll need to rely on second-hand or third-party providers. While these may not always be reputable, they can provide solutions for these older but still functional drones.

Enterprise Drones: For Those Seeking a Professional Career

The final and most advanced category is the Enterprise drones. Despite what the name might suggest, you don’t necessarily have to invest upwards of $5000 for a complete setup. DJI has designed a more affordable yet highly capable option – the DJI Mavic 3 Enterprise. This drone has quickly gained popularity in the industry for its superior capabilities in comparison to its competitors.

Enterprise drones offer extended flight times, superior sensors, and even Real Time Kinematic (RTK) capabilities for precise data capture. The DJI Mavic 3 Enterprise is a personal favorite and comes highly recommended. This is an unbiased endorsement, as the drone has been purchased with personal funds and has proven to be the most utilized amongst others for most projects.

A few other drones in this category worth considering include the DJI M30T, DJI M300 RTK, WingtraOne Gen 2 (a VTOL drone), and Autel Evo 2 Pro RTK.

Matching Drone Capabilities with Client Requirements

As you evaluate these categories – beginner, advanced, and enterprise, remember that the choice of drone largely depends on what your client is seeking. Not every project will necessitate the use of an Enterprise drone. In some cases, an advanced or even a beginner drone can deliver high-quality data, which we will elaborate on in subsequent sections of this article.

Remember, the drone itself is not the end goal of your business; it is a tool to provide the service that your client requires. The cost of acquiring an enterprise-grade drone can be significantly higher than that of beginner or advanced drones. Therefore, understanding the deliverables and aligning them with your clients’ needs is essential in making the best investment decision.

Drone Software for Data Capture

In the sphere of software for drone photogrammetry mapping, a noteworthy distinction exists between data acquisition software and data processing and analytics software. Some manufacturers develop comprehensive solutions catering to both aspects, while others concentrate on a specific function.

Free Data Acquisition Software Options

On the data acquisition front, several options are available. Notably, free software solutions include DJI Pilot 2, Map Pilot Pro, and Pix4D Capture.

  • DJI Pilot 2: Bundled standard with all DJI Enterprise series drones, DJI Pilot 2 provides an intuitive interface for drone navigation and data capture.
  • Map Pilot Pro: Ideal for beginners, Map Pilot Pro simplifies the process of mapping and capturing data.
  • Pix4D Capture: An excellent choice if you’re utilizing a DJI Phantom 4 Pro or Mavic 2 Pro drone.

There are also additional free options available, but the above-mentioned ones are highly recommended for their utility and comprehensive feature sets.

Paid Data Acquisition Software Solutions

On the other side of the spectrum, paid data acquisition software offers more functionality, such as advanced automated flight plans. Options in this category include DroneDeploy, Drone Link, and UGCS.

  • DroneDeploy: This paid software provides advanced features like 3D capture capabilities, making it a valuable tool for detailed mapping projects.
  • Drone Link: Known for its dynamic automated video flight paths feature, Drone Link offers unique capabilities for those requiring video-based data capture.
  • UGCS: This software stands out for its vertical capture feature, providing an added dimension to drone mapping.

These paid data acquisition software solutions unlock more capabilities, enabling a more precise and thorough approach to drone data capture.

The Role of Data Acquisition Software in Photogrammetry

While data acquisition software is not a strict necessity for producing photogrammetry models, it greatly simplifies the process and ensures consistent data capture. Remember that photogrammetry fundamentally involves stitching together a series of images. The role of data acquisition software is to streamline this process, ensuring consistent data capture and thus leading to a higher quality model in the stitching process.

In essence, by choosing the right software, drone operators can enhance the efficiency of their data capture process and ultimately produce superior photogrammetry models.

Drone Software: Data Processing and Visualization

When it comes to data processing and visualization in drone software, a myriad of options are available. These tools vary in their feature sets, and are designed with a common objective – to combine and stitch together photographs into functional deliverables for clients.

Free Drone Software Options: Open DroneMap and Web ODM

Initiating our exploration with cost-effective options, Open DroneMap or Web ODM emerge as viable choices. These tools generate fundamental file types such as point clouds and orthomosaics, among others. They leverage the power of your computer to accomplish all processing tasks. If you’re searching for a cloud-based version of this software, Maps Made Easy offers a solution. This tool allows you to process your data in the cloud, free of charge. For an in-depth examination of Maps Made Easy, you can refer to this detailed analysis, shedding light on its features and functionality.

High-End Drone Software: DroneDeploy and More

Transitioning towards the more premium range of drone software, we encounter DroneDeploy. Regarded as a turnkey solution, DroneDeploy adeptly handles data acquisition, processing, and visualization. However, DroneDeploy is far from the only choice in this category. Other noteworthy high-end software options include DJI Terra, Pix4D, Capture Reality Capture, and more.

While each of these tools primarily perform the same basic processing functions, differences emerge in the deliverables they can produce, their unique capabilities, and the quality of their results. Therefore, it is recommended that you thoroughly browse through the extensive list of drone software provided, to ascertain the one best suited to fulfill your requirements. This comprehensive list offers a helpful resource to make an informed decision.

Generating Accurate Models with Drone Data

Capturing data with your drone constitutes only part of the process when offering it as a service. Equally crucial is ensuring geographical accuracy in the captured data. This requires taking into account client requirements, available resources, and appropriate methods for data correction. The approach taken may vary, especially if the client merely requires visual accuracy, which could potentially obviate the need for this step.

Drone Data Correction with RTK

Real-Time Kinematic (RTK) offers a method for correcting GPS data in the drone, a critical process that can provide centimeter-level accuracy for your deliverables. There are both free and paid options available for this, and the choice largely depends on your location.

Enhancing Geographical Accuracy with GCPs

An alternative way to enhance geographical data accuracy is by employing Ground Control Points (GCPs). GCPs are physical markers placed on the ground that you can correlate with your aerial data. To gain a more in-depth understanding of GCPs, we recommend our comprehensive article dedicated entirely to this topic.

Having explored the essentials of drone photogrammetry and mapping, it’s important to discuss some of the industries that benefit from this type of data.

Drone Usage in Construction and Development

Drones have proven to be a highly valuable tool in the construction and development sector, allowing all involved parties to maintain a current, top-down view of ongoing projects. By leveraging drones, stakeholders can create near real-time satellite imagery of a property, enabling developers, contractors, and investors to make informed decisions throughout the project’s lifecycle.

Drones in Engineering Firms

Engineering firms worldwide rely on photogrammetry, not only for new, undeveloped projects but also for modifications to existing ones. The ability to use drones to generate photogrammetric models has significantly reduced costs as data acquisition expenses have dropped markedly.

Construction and engineering firms are just two examples among many industries that regularly utilize drone services. Drone technology continues to evolve, providing more precise and accessible data collection methods that are proving invaluable across a range of sectors.

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