Drone Survey & Troubleshooting

Overview

You will usually be asked to capture drone photos for most survey types and scopes.

WHAT TO GATHER

A good drone flight consists of capturing the following photos:
Top-down photos
Orbit photos
Shingle quality close-up (~2')
Close-up photo of each roof face (~5')
Shingle layer close-up (~2')
Obstructions that shade the roof
Horizontal ridge sag
Birds eye view property shot

WHY WE NEED IT

The drone photos are stitched together using 3D modeling software to create a 3D model of the house. We use the model to measure the roof and any obstructions that would cause shading. Photos of shingles will help determine if the roof needs to be replaced before installing solar panels, and photos of ridge sag will help the structural engineer determine if the roof can withstand the weight of solar panels.

Placing Reference Sticks

Before you do the drone flight, you will need to place reference sticks on the ground near the house. These reference sticks are used to confirm measurements in the 3D model of the home. It is important to place them properly so that they are captured clearly in the drone photos.

KEYS TO SUCCESS

Sticks must be exactly 96" long
Place on flat ground
Make sure sticks are not touching
Do not place under trees or obstructions - must be fully visible in drone flight
Do not move sticks during drone flight

Do not!

Place the sticks in a shady area. It might turn out blurry!

Do not!

Use bent sticks. It will not be exactly 96" and won't be usable.

Other Methods:

Instead of using reference sticks, you can use a tape measure and mark it with a piece of duct tape at exactly 96". Please use your phone to take a close-up picture of the duct tape marking so we can verify it was placed at exactly 96".

Top-Down/Grid Pattern Flight: Specifications & Guidelines

Gimbal Angle: -90° (directly downward)
Height (above ground): 20-30 feet above the ridge line. Fly higher if it is a large home or if the roof has a greater pitch. Fly lower if it is a smaller home or if the pitch is flat. The height should be consistent for all the photos in the top-down flight.
# of Photos: 30 - 50 (depending on the size of the house)

Top-Down/Grid Pattern Flight: Keys to Success

Use an automation program such as Drone Deploy
This will improve your flight and efficiency
Use the altimeter on-screen to set the height
Take photos beyond the edges of the roof on all four sides, don't stop right at the roof edge
Each pass over the house should overlap the last one by 80% -- at least 5 passes over the house is a good rule of thumb
Take all photos at the same height
Capture the reference sticks
If a tree obstructs the top-down path, fly around the tree, staying at the same height. Changing the height of the photos will interfere with the 3D model rendering.

Orbit Flight: Specifications & Guidelines

Gimbal Angle: -30° to -45°
Height: Aim to fly at an elevation where the roof of the house occupies 70% of the camera's frame. The height and gimbal angle of each photo should be consistent throughout the orbit.
# of Photos: 30 - 50 (depending on the size of the roof)

Orbit Flight: Keys to Success

Use an automation program such as DJI Point of Interest
This will improve your flight making it more stable as well as improving efficiency and reducing survey times
The radius of the orbit should not be too big or too far away - the house should take up most of the frame (70% of the frame is a good rule of thumb)
If you cannot get a perfect circle, don't worry, it is more important to get the whole house in each shot
The adjacent roof face should be visible in the shot, and the nearest wall should be visible (see bottom left)
Avoid capturing the horizon as this interferes with 3D model
Elevation and gimbal consistency between shots is the most important factor
If a tree obstructs the path of the drone, conduct the entire flight path above the tallest point or tree, and adjust the gimbal angle to ensure the house is still captured in the orbit photos
Do not capture multiple photos from the same position in the orbit. It should be one complete flight path with one picture at each point in the circle

Do:

Ensure the adjacent roof is visible in the shots.

Do not!

Capture the horizon in the shots.

Shingle Layer: Specifications & Guidelines

Our surveys require close-ups of the shingles so that we can determine how many shingle layers are on the roof. Some older roofs have more than one layer of shingles, which will require longer screws in order to install the solar panels.

Gimbal Angle: ~0°
Height: Level with roof edge
# of Photos: 3 - 5 photos per roof face that will have panels on.

Shingle Layer: Keys to Success

Collect Rake Edge Close Up
Collect Bottom Up at the edge of the eaves
Photos should be directly facing the roof edge so we can count the shingle layers

Ridge Sag Photos

Ridge sag photos tell us whether the ridge is bending in the middle, which could mean structural problems in the house.

Gimbal Angle: ~0°
Height: Level with ridge
# of Photos: 3 - 5

Trees

Please take additional photos of trees that might cast shadows on the house. Trees that are outside of the top-down and orbit flight paths will not develop properly in the 3D model, so we ask for these extra pictures to help determine the height of the trees on the property. We require tree height so that we can determine how much shade will be cast on the roof, and therefore how much power the solar panels will generate. You will also be required to capture these trees via ground-based photos using your smartphone, tablet, or camera.

Gimbal Angle: ~0°

Height: Top of the tree

# of Photos: 3 - 5

Keys to Success:

Position the top of the obstruction in the middle of the frame

Bird's Eye View Shots

Please take a top-down photo of the property and any other photos you think might provide some context about the property.

Gimbal Angle: -90°
Height: As much of the property as possible while still adhering to drone altitude limits
# of Photos: 1 - 2

Keys to Success for Drone Flights

The higher the quality of the photos the better
Avoid motion blur - come to a complete stop to take photos, especially on cloudy days
Orbit flight path photos must be consistent in altitude and in gimbal angle
Exposure settings should be kept on AUTO
Only capture photos in JPEG format

Drone Flight Example 1.mp4

Drone Flight Authorization Troubleshooting

As mentioned in a previous course where we went over the Exactus Planner, this is a tool where the Clients can go and book site surveys. However, keep in mind these are usually sales representatives with no knowledge of airspaces. Thus, as a certified drone pilot, it is your responsibility to check the airspace for every new booking you receive and apply for authorization if necessary. A few takeaways are:

If the process requires more than 72 hours and we are still within time, apply for approval.
We aim to schedule surveys with at least a 24-hour notice. There would be some cases where this would happen where approval would not be possible due to a short timeline. In those cases, we can do a Hover.
In the event of a restricted airspace where authorization is not possible, we can do a Hover.
Finally, if you apply for authorization but the survey date has come and you are yet to receive approval, we can do a Hover.

We aim to complete a drone flight for every site visit we complete. However, for any address where you won't be able to fly, make sure to report it to the Field Operations Team along with the reason.Exactus Energy operates in both Canadian and US markets. Below are official resources we recommend depending on your country. Disclaimer: While Exactus Energy operates in both markets, you won't be required to complete work cross-country.

US Pilots

We highly recommend reviewing the Part 107 Airspace Authorization Article by the FAA to get a better understanding of the difference between LAANC approval through B4UFLY and restricted airspace approval through the FAA Drone Zone portal.

CAN Pilots

For Canadian pilots, you can review our Canada's Airspace (NAV Canada) document to get a better understanding of how to apply for Authorization using NAV Drone.

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