Drone Roof Inspections: A step-by-step Guide
Roof Inspections have always been challenging, especially when your subject is a tall structure or building, so what options are there to overcome this challenge?
Generally, the default option used to be scaffolding or a cherry picker but this came with its own challenges - Scaffolding is expensive and takes time to construct and take down, and you have to rely on a scaffolding team to install the scaffolding around your structure or building. Cherry pickers are also expensive and they can't always reach the areas that you may need to inspect.
This is where using a drone to perform your roof inspection comes in.
Drones have changed the game. Not only can you reach hard-to-access areas in a fraction of the time, but you can also record and capture high-resolution images of the roof of the building. These images can be later used to analyse the roof condition collaboratively in an office environment.
In this post, we will discuss the step-by-step drone workflow to inspect a building's roof.
We will be looking the exact setup (hardware and software) we used and the end deliverables that were produced.
Mission & Requirements
In this mission, our goal was to capture and analyze the roof of an old abandoned Mill. This Mill is located in UK and our goal was the inspect the roof of the building.
Data Quality Requirements:
100 % of the roof captured
70%+ overlap between images
Images in Focus and devoid of blur
Efficient & Repeatable Workflow
2D roof Images as per quality requirements.
Geolocated, Annotated Images.
2D Map of inspected roof
Web Link to the Project, viewable on a web browser.
PDF Report with detected issues.
The DJI Mavic Pro 2 is highly portable and produces detailed-enough photos from its 20 Megapixel sensor, more information on why sensor sizes and megapixels matter in drone photography can be found in our post.
Planning the Mission
We used Hammer Hub to locate the building to perform the Roof Inspection.
Selected the (+) icon in the top right-hand corner.
Selected the Roof Inspection mission for our capture method.
We planned the mission by creating a polygon over the top of the structure to capture the entire roof.
We adjusted our parameters accordingly by using the settings icon.
We made sure the height and overlap were correctly set and that our ground offset was in place.
We also turned on Show Planned Images to give us an insight into where the pictures were being taken.
Download The Mission To Hammer App
Before heading out to the field we downloaded the planned Roof Inspection Mission to the Hammer App
Then, we opened the Hammer App
Within the mission files section, select the cloud option at the top of the screen
You can also simulate the mission before you head out to the field. You will see the altitude change in the simulation to emulate the altitude change in the field.
Once on site you can calculate the correct altitude and distance to target to ensure safety and mitigate any risk. We did this to ensure that our all mission parameters are correct.
Ideally, you would initially take the drone up prior to using Hammer Missions and check that your mission planning parameters are correct.
It is also advisable to check the distance to the target to make sure your estimates are correct before you use an automated flight.
Once you have done this you can open the Hammer App and make the adjustments if required.
Capturing The Data
After making the relevant adjustments so that we were happy with the distances, we went ahead and launched the drone to start the data collection.
We set the drone up in a safe area to take off and pressed the play button in the Hammer App. The video below demonstrates our capture at the target building and will go through the whole process from take-off to landing.
Verifying Drone Roof Inspection
Once the flight has been completed you can, if you wish, verify the data before you leave the site. You would need to remove the memory card from the drone and check the data on your laptop to make sure you are happy with the results and that all data has been captured correctly and is in focus.
Alternatively, you can use our Data Verification tool in the Hammer App. For more information on our data verification tool please see the video below:
Upload Data to Hammer Hub
Now we had collected the data and verified it in the field we started the process of uploading it to the Hammer Hub for data analysis.
Opened Hammer Hub. On the left pane > selected Data Analysis
Then select 'New Project' in the top right corner
We put in a title and type for the project.
Then, pressed continue and chose our images from the job site.
Now that images were selected, we uploaded those images to Hammer Hub.
This is done by pressing the Create Project button. This will start the process of uploading your images
Depending on the amount of images this can take some time.
This is a good time to make a cup of your favourite hot beverage and ensure that all flight logging and mission planning data was logged and captured from the flight!
Process The Data Into A 2D Map
Once the data was uploaded, we decided to process it into a 2D Map using Hammer Hub for additional context. To do this:
Open the Project
You will see that you now have all of your images and a mini-map on the left-hand side with your selected picture on the right.
Select the Process button in the top right corner
Now Select 2D Map from the options
Depending on the amount of images this can take some time.
You will be notified by email of the various steps while your 2D map is being processed.
Viewing the 2D Map
Once the data has been processed, it will be viewable as a 2D Map.
We then draw annotations on our 2D Map to mark areas that may need specific attention.
On the picture that corresponds with the correct part of the 2D map hold down the shift key and draw a box around the specific area in question.
This will give you the option to add a note to that specified annotation.
💡 All the notes and annotations are saved with the project, so if you were to share the project, all annotations will be shared as well.
Sharing and Creating Reports
Once we were done annotating, the project was ready to be delivered. To do this, we simply shared the project with clients, stakeholders, and fellow team members by inviting them to Hammer Hub or sharing a private link to the project. You can also then generate PDF reports on the project.
To share the project, select Share in the top right-hand corner.
(note: names have been removed for privacy purposes)
From here you can share with team members or share with clients and stakeholders via a generated link.
To generate a report select Report from the top right-hand corner
From here you can format and generate a report on your findings.
In this guide, we detail the steps we undertook to perform a drone-based roof inspection project with the aim of satisfying specific requirements on data quality, workflows and deliverables.
We hope this guide helps you understand the typical workflow behind a drone facade inspection and how to process the collected data.
If you'd like to learn more about how to capture high-quality data and get the most out of your drone flights using our cloud-based platform, please feel free to visit our learning resources.
To learn more about our enterprise solutions, including mission collaboration, data processing, and AI solutions, please contact us at firstname.lastname@example.org.
We look forward to hearing from you.
— Team at Hammer Missions