Drone mapping software is notoriously expensive. While most of these mapping engines offer free trials, along with lesser expensive options, there is no free drone mapping software other than Web ODM (also known as ODM).
Web ODM is an open-source drone mapping software designed for all purposes. WebODM was first designed in 2016 and has been upgraded regularly.
Since WebODM is open source, anyone with a background in software design is able to manipulate the program to suit their needs. Most of us, however, are not so tech-savvy.
WebODM in its base model is ready to map and excels at processing accurate and detailed maps and models.
The hardest part about using WebODM is the installation. There are several steps to follow in order to download and install. This is the price you pay for using a free app.
Read on to get the step-by-step installation.
How to install ODM for Windows, Mac, and Linux
Step 1. Download Docker. This is an app that allows you to run WebODM on your computer.
Step 2. Download guitar GitHub. Github is an application that runs code to download and install Web ODM to the Docker platform. While this may sound daunting, it is actually quite simple.
Step 3. Open Docker, open GitHub, and paste in this line of code:
git clone https://github.com/OpenDroneMap/WebODM –config core.autocrlf=input –depth 1 cd WebODM ./webodm.sh start
Once copied, paste it into the Github app and press enter. This will allow your computer to begin downloading and running Web ODM. This can take quite some time, so grab a coffee and a donut while you wait.
The end of the process will result in WebODM opening up in Docker.
If this doesn’t work, see here and scroll down for help and more lines of code.
Now you’ll need to open your internet browser and type in: Localhost:8000
(It’s okay if you don’t have a connection to the internet)
You should be shown a login screen/sign-up screen to create your account.
The paid (but basically free version)
The alternative method of downloading WebODM is not free but might as well be compared to the other drone mapping software available out there. This method is known as easy installation and requires you to pay a one-time fee of $57.
Honestly, WebODM is so good that if I were to download it again, I might choose this option just to support the company. See here for the paid option.
How to Use WebODM
Once you’ve successfully downloaded WebODM and have it running on your computer , you’ll be able to begin processing your drone imagery. It’s important to remember that to create a quality map and models,images need to have 70% overlap in each dataset.
Note: WebODM is only a drone mapping software, not an automated flight platform. In order to collect drone images in a grid pattern and with 70 percent overlap, you need to download a flight planner and fly the mission manually following the flight plan. Or download an automated flight software. Most of the software is not free, but you will find some that are quite cheap. If you have a drone such as a Phantom 4 RTK, your drone already has an automated flight executed in it and does not need to download any other software.
WebODM is a local software, which means it runs on your computer. This is important because when selecting your drone imagery, you’ll have to be aware of how many images you are actually uploading to WebODM.
If your computer has low memory, less than 16 GB, you’ll want to stay away from large datasets. A good rule of thumb to follow if your computer has less than 16 GB of memory is to keep your drone images to 100 or less per dataset.
The possibilities open up widely when your computer has over 16 GB of memory. Some users have been able to process over 1,000 images for a data set when the memory is above 16 GB.
Once you’ve successfully uploaded your images, you’ll select what type of map output you want. This is another way WebODM sets itself apart from other software.
WebODM allows you to select whether you want to prioritize:
- Orthomosaic quality
- Speed of processing
- DTM or DSM (elevation and topography)
- The forest canopy
- Point of Interest
- 3D Models
- Volume Analysis
Once you have selected the type of map you want, upload the images. The photos should upload fairly quickly, and then you will press review as shown below. Now WebODM begins processing your map and 3D model.
Shown below is an example of how a WebODM orthomosaic will look once exported from WebODM.
This output is the central output from WebODM. The orthomosaic is the combination of all your images and the data within them to determine elevation, plant health volume, and build the 3D model. However, the orthomosaic is just the 2D map of the site you’re mapping.
When you export the orthomosaic, it will be a .tif file. Tif files are geo-referenced images containing data such as location on planet earth, as well as thousands of kilobytes of image data since your images have been combined into one.
How to create a 3D Model
Shown below is an example of the 3-D model in point cloud format within the WebODM software. As you can see, on the left-hand side are tools and options for the 3-D model.
You can turn that point cloud into a textured model similar to what you might see on google earth or a video game. When the 3-D model is exported, it will be in the format of a textured model.
Along with the exports already covered, also included is the Web ODM report, which contains crucial data on the quality of the survey as well as the model of drone used to conduct the survey and contains previews of the exports from the drone survey.
Another export from the software is the DSM digital surface model and the DTM, or digital terrain model. These models are crucial to generating the tomographic map shown below.
If the DSM, DTM, and topographic map are the priority outcomes from the aerial survey, you need to select DTM+DSM in the map type before you upload and process the images.
WebODM offers tools to conduct measurements on the orthomosaic, such as volume measurement, area measurement, perimeter measurement, and more. This is highly useful if you wish to determine a construction site’s stockpile of materials.
Shown below is an example of a volume measurement using WebODM.
WebODM allows users to process their drone imagery into a plant health map. As shown below, the plant health map is a combination of images, usually containing metadata such as geographic location, RGB reflectivity, and elevation of the surface of the ground in relation to the camera.
To produce a more accurate orthomosaic, and therefore extract more accurate measurements, it is necessary to use ground control points. If you’re not familiar with ground control points or GCPs, they are spots on the ground at which you know the exact location on earth.
Most of the time, it is necessary to use surveying equipment to gather the exact point at which the ground control point sits.
WebODM offers a ground control points platform within the application. To access the ground control point platform, click on the tab that says “GCP Interface” shown below.
Using ground control points on WebODM is not always the most user-friendly. It becomes easier once you get the hang of it. However, the video shown below will give you an idea of what you need to do to effectively gather and upload ground control points.
WebODM alone is a very effective software; however, it is often paired with another free mapping platform to manipulate your data collected and processed with WebODM.
This software is called QGIS. This software is aimed at professionals and individuals who are proficient in using GIS platforms. GIS is short for geographic information systems, and essentially it is a mapmaking and map manipulating platform to which you can upload your orthomosaics from WebODM.
A benefit of using QGIS in tandem with WebODM is its ability to re-project your orthomosaic’s coordinate system into local coordinate systems such as Nad 83. This is beneficial if you are working with a company whose maps are all in a coordinate system not listed on WebODM.
The coordinate system in WebODM can be found in the top right of the image shown below.
This is seemingly the only drawback to WebODM, in the sense that you are limited to which coordinate system you are using. Aside from this singular drawback, WebODM remains in the competition for the top drone mapping software, and certainly wins the competition for best free drone mapping software.
The Best Free Drone Mapping Software
The fact that WebODM is a free drone mapping platform speaks volumes to the creators’ ethics as well as the creators’ ability to create a proficient application.
It is truly a wonder that software as useful and advanced as WebODM is free. But we are so happy that it is.
Image Credit: Unmanned Aerial Operations