Drone Mapping Comprehensive Photogrammetry
Mapping or Modeling with drones has become a relatively large aspect of many drone businesses. Aerial Photogrammetry has enabled such things as construction sites having remote verification of permanent installation by subcontractors, or resorts to create an interactive model of their property for potential guests and conventions. Even surveying companies are mapping with drones to model their sites. The data collected from this process (when done correctly) gives clients an unprecedented level of data.
In this truly comprehensive training, we will show you everything we’ve learned in this process. Why go out and learn the hard way when you can learn from those who are actually doing it? We’ll take you through our very thorough process that includes setting up your systems for Photogrammetry processing, acquiring exceptional 3D data using a multi-faceted strategies, mastering the workflow of processing images and creating 2D models, manipulating Point Clouds, and providing deliverables to clients. You will receive resource documentation to ensure your field work is in line with the concepts and systems learned in this training.
This is without a doubt a fast growing segment of the drone industry and as applications for it continue to evolve, it should remain a thriving niche. Don’t be left behind! You’re ability as a drone business to offer such services will give you a high demand niche and a “leg up” on most your competition. Even if you don’t currently have a drone business, knowing this segment will give you a great “launch pad” to start and grow your business. Come learn for yourself why many who have taken this training tell us it is “one of the most comprehensive and systematic mapping trainings on the planet.” We’d love the
opportunity to help you launch this niche in your market. You’ll be glad you did!
“Better data equals better decisions.”
As you can see from those examples, drone mapping provides a truly unprecedented level of detail and data for companies. This helps them make better, more informed decisions, which leads to increased profitability, which can then lead to increased opportunities, and the cycle goes from there. Drone mapping is powerful! How many problems can drone data help solve? The possibilities are almost limitless.
To give some sense of form to that limitless space, here’s a great article to check out by Propeller Aerobotics. It will give you some ideas of what can be measured with drones and volumetric tools.
The construction industry benefits from operational efficiencies provided by aerial data via drone mapping. With the ability to gather linear and volumetric measurements from the sky, construction engineers and general contractors can remotely audit the progress and process of a project without ever stepping foot on the site. This includes things like remotely analyzing stockpiles of raw materials, general 3D point clouds for permanent records of installations, and auditing cut and fill calculations, even ensuring that the elevations gathered are accurate.
- 3D Point Cloud
- DXF File
- Index Maps
- Volume Calculations
Now that you have a firm understanding of the value and benefit of drone mapping, let’s take a look at the key terms in this drone niche. As we do that, don’t get overwhelmed with all the vernacular! There are many terms here so you can get familiar with the “language”. It takes time to get these down, so bookmark this page and refer to it when needed.
Drone Mapping/Modeling –
Creating 2D maps and 3D models from aerial pictures via a process called photogrammetry.
Data Acquisition Plan –
It summarizes the acquisition planning discussions and identifies milestones in the acquisition process.
The use of photography in surveying and mapping to measure distances between objects.
GCP-ground control point –
is a characteristic point whose coordinates are known. Their coordinates have been measured with traditional surveying methods or have been obtained by other sources (LiDAR, older maps of the area, Web Map Service). GCPs are used to georeference a project and reduce the noise.
An Automatic Tie Points is a 3D point and its corresponding 2D key points that were automatically detected in the images and used to compute its 3D position.
Manual Tie Point –
A Manual Tie Point is a point without 3D coordinates that is marked by the user in the images. It can be used to assess and improve the reconstruction accuracy.
Densified Point Cloud –
The densified point cloud is a set of 3D points that reconstruct the model. The X,Y,Z position and the color information is stored for each point of the densified point cloud.
Classified Point Cloud –
can showcase the differences between vegetation, road surface, ground surface, and man-made structures. Classified point clouds make it easy to show only specific parts of a model.
Mesh (Triangle Meshes) –
The 3D textured mesh is a representation of the shape of the model that consists of vertices, edges, faces and the texture from the images that is projected on it.
The orthomosaic is a 2D map. Each point contains X, Y and color information. The orthomosaic has uniform scale and can be used for 2D measurements (distance, surface). It corrects the following problems of the input images:
- Perspective of the camera.
- Different scale based on the distance that each point of the object/ground has from the camera.
The digital terrain model (DTM) is a 2.5 D model of the mapped area after filtering out the objects, like buildings. It can be exported in GeoTIFF raster file format.
The digital surface model (DSM) is a 2.5 D model of the mapped area. It can be exported as two different types of files:
- Raster GeoTIFF.
- Vector point cloud (.xyz, .las, .laz).
KML is a file format used to display geographic data in an Earth browser such as Google Earth.
The normalized difference vegetation index (NDVI) is a simple graphical indicator that can be used to analyze remote sensing measurements, typically, but not necessarily, from a space platform, and assess whether the target being observed contains live green vegetation or not.
Infrared thermography, thermal imaging, and thermal video are examples of infrared imaging science. Thermographic cameras usually detect radiation in the long-infrared range of the electromagnetic spectrum and produce images of that radiation, called thermograms.
GSD (Ground Sampling Distance) –
The Ground Sampling Distance (GSD) is the distance between two consecutive pixel centers measured on the ground. The bigger the value of the image GSD, the lower the spatial resolution of the image and the less visible details.The GSD is related to the flight height: the higher the altitude of the flight,the bigger the GSD value.
- A GSD of 5 cm means that one pixel in the image represents linearly 5 cm on the ground (5*5 = 25 square centimeters).
- A GSD of 10 m means that one pixel in the image represents linearly 10 m on the ground (10*10 = 100 square meters).
Absolute Accuracy –
It is the accuracy that is defined by the difference between the location of features on a map/reconstructed model/orthomosaic and their true position on the Earth.
Relative Accuracy –
It is the accuracy that is defined by comparing individual features on a map/reconstructed model/orthomosaic with other features on the same model. For example, two points of the model can be 2 meters away from their real position on the earth but if their relative accuracy is high, then the distance measured between these points will be very accurate as it is related with the relative position of the points.
A geographic information system (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present spatial or geographic data.
The Global Positioning System (GPS), originally Navstar GPS,  is a satellite-based radionavigation system owned by the United States government and operated by the United States Air Force.  It is a global navigation satellite system that provides geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. 
RTK GPS –
Also know as Real Time Kinematic satellite navigation, this is a centimeter-accurate technique of obtaining GPS (or any GNSS) data. Essentially, the RTK receiver analyzes the GPS radio signal to calculate this data.
Not all RTK drones actually utilize the onboard RTK data and write that on the images to create highly precise models. Currently only the Phantom 4 RTK can create drone maps without GCP’s if the conditions are perfect and network access is available.
It’s a common misconception that all drone mapping apps complete the same job. To be clear, they do NOT. In fact, all drone mapping apps fall into one of three categories, with each app performing different functions and for different type projects.
Assist in planning autonomous missions to acquire aerial imagery. Examples in this category are Maps Made Easy, Pix4D Capture, and UCGS.
Use photogrametric calculations to create point clouds, maps, orthomosaics, and other deliverables from imagery. Examples in this category are Pix4D Mapper, Photoscan Agisoft, gently, and Inpho.
Can plan autonomous missions to acquire data, transmit the data to a cloud server, and then autonomously process that data in the cloud to create output deliverables. Examples in this category are Skycatch and DroneDeploy.
The differences between desktop (acquisition and processing) and cloud processing (all-in-one) software are the cloud processors typically have less customization so as to ensure results containing higher accuracy and consistency. Cloud processing solutions also typically use an industry standard desktop-based app for processingdata in the cloud. It is, therefore, great for companies doing significant, large-scale mapping jobs.
Let’s dive deeper into some of the different drone mapping software applications available today (including some of our favorites). Please note that this list does not include every mapping software on the market, some of which weve mentioned above.
Maps Made Easy is a web-based company out of San Diego that offers “pay-as-you-go” mapping solutions. Their application has become the industry standard for autonomous mission planning requiring terrain awareness, which is an important solution to have for solving the problem of acquiring data in areas with extreme elevation change. It can control DJI and other select drones.
Pix4D is a Swiss company offering a suite of photogrammetric software. Their mobile app is Pix4Dcapture and will automate the mapping process with DJI, Parrot, Yuneec, and other select drones.
This app has become the industry standard for capturing drone mapping data, with multiple features for orbital capture, double grid capture, nadir flights, and free fly mode. The Free Flight Mode is especially valuable to drone mapping pilots who need to map complex areas. This mode will automatically calibrate overlapping images captured during manual flight as the pilot controls the drone.
UGCS is a Latvian company that offers an easy-to-use software to plan and fly drone survey missions, it supports almost any UAV platform, providing convenient tools for aerial and linear surveys and enabling direct drone control. UGCS enables professional land survey mission planning using photogrammetry technique.
Pix4D’s most well known software in their suite of photogrammetric mapping tools is Pix4Dmapper. It processes any image and creates 3D point clouds and 2D maps.
Known in the industry as the most powerful, capable, and customizable solution on the market, Pix4D has become the gold standard for photogrammetry processing software. It is technically the most statistically accurate as well.
RealityCapture is photogrammetry software which creates 3D models out of unordered photographs or laser scans without seams. The most common fields for its current use are cultural heritage, full body scanning, gaming, surveying, mapping, visual effects, and virtual reality in general.
RealityCapture has become the industry standard for creating highly detailed graphical representations of maps or 3D models. It creates the most life-like 3D textured meshes on the market.
DroneDeploy has become the industry leader for all-in-one photogrammetry solutions. With multiple purchase options, it’s able to serve a wide audience of users. The only negative aspect of using a cloud based service like this is the inability to control many settings that can increase the output quality of the deliverables.
Skycatch is a San Francisco-based company founded in 2013 that primarily focuses on enterprise grade solutions for construction based applications. Skycatch has developed a new element to drone mapping by providing an on-site processing solution. Utilizing pre-designed templates, it’s able to process data onsite via hardware that communicates with the drone, vastly increasing the speed of processing.
Agisoft’s photogrammetry software, known as Metashape or Photoscan, creates panorama stitching and support for fisheye lenses. Using the professional version of their software, you can make point clouds, digital elevation models, take measurements, and process RGB, NIR, thermal, and multi-spectral imagery. Agisoft is great for professionals who need an all in one package for photogrammetry and 3D modeling (like architects, GIS professionals, civil engineers, and media professionals).
The best way to learn drone mapping is from those who have already been doing it. You can glean from their experiences, both good and bad, and substantially lower your learning curve.