Drone Facade Mapping & Inspection - A step-by-step Guide.
Updated: Nov 3, 2022
Facade Mapping & Inspection 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 facade mapping or 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 building facade. These images can be later used to analyse the facade's condition collaboratively in an office environment.
In this post, we will discuss the step-by-step drone workflow to inspect a building facade.
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 one of the facades of an old abandoned Mill. This Mill is located at Robertsbrige, UK and our goal was the inspect the facade on the far side of the building.
Data Quality Requirements:
90%+ of the facade captured
80% overlap between images
Images in Focus and devoid of blur
Efficient & Repeatable Workflow
2D Facade Images as per quality requirements.
Geolocated, Annotated Images.
3D Model of facade (optional extra).
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 Facade Mapping.
Selected the (+) icon in the top right-hand corner.
Selected the Facade Mapping mission for continuous capture.
We planned the mission by create points down the facade of the target building .
Download The Mission To Hammer App
Before heading out to the field we downloaded the planned Facade Mission to the Hammer App
Then, we opened the Hammer App
Within the mission files section, selected 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.
On Site Settings
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 take the readings from the altitude at the top of the structure and from as near to the bottom of the structure as you can.
It is also advisable to check the distance to target to make sure your estimates are correct before you use automated flight.
Once you have done this you can open the Hammer App and make the adjustments.
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 live Facade Capture capture at the target building and will go through the whole process from take off to landing.
Verifying The Data
Once the flight has 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.
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 selected '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
Dependant 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 3D Model
Once the data was uploaded, we decided to process it into a 3D Model 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 right hand side with your selected picture on the left.
Select the Process button in the top right corner
Dependant on the amount of images this can take some time.
You will typically be notified by email when you 3D model is ready.
Viewing the 3D Model
Once the data has been processed, it will be viewable as a 3D model.
We then draw annotations on our 3D model to mark areas that may need specific attention.
On the picture that corresponds with the correct part of the 3D image 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, 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.
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 facade inspection project with the aim of satisfying specific requirements on data quality, workflows and deliverables.
Curious to see the results for yourself? Here's a link to the project: https://hub.hammermissions.com/s/dpp_1582c1426f204f1ab14f176f1af0642b
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 email@example.com.
We look forward to hearing from you.
— Team at Hammer Missions