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Data acquisition checklist PV thermography

Data acquisition checklist PV thermography

 

Below is a checklist of what you need to keep in mind when it comes to data acquisition.

Note: Volateq can only start the process described below if there is a purchasing confirmation, such as a Signed Sales Order or a Purchase Order.

Upon reception of the purchasing confirmation we will schedule a short pilot briefing call to go through the points listed below. This will clarify any questions and make sure everything is ready for takeoff.

Before flight day

Make sure that Volateq team informed you that the flight routes are ready for your site. Experienced customers can set up their own flight routes: https://volateq.atlassian.net/wiki/spaces/VKB/pages/4251320321
RTK is best (but not mandatory) for precise flight routes and high quality data. make sure your RTK service is active and connecting on your drone. For more info see: https://volateq.atlassian.net/wiki/spaces/VKB/pages/3411345427. Flying without RTK bares the risk that in case of insufficiently accurate GPS positions resulting orthomosaics contain defects.
We recommend using the VolaFly Drone App. Instructions on how to install it on your drone controller can be found here: https://volateq.atlassian.net/wiki/spaces/VKB/pages/2957148162
Check if you have a fast enough SD card. Recommended SD cards: SanDisk Extreme 128GB V30 microSDXC or SanDisk Extreme Pro 128GB V30 microSDXC

Conditions and preparations before drone flight

weather:
Wind speed below 5 m/s
Less than 10% of sky are covered by clouds. If a cloud casts shadow on parts of the solar field during the drone flight, the flight has to be repeated some 10-15 minutes after the cloud has left
The weather is clear and sunny, no clouds, with irradiance (plane of array POA) > 650 W/m2
for thermography data acquisition:
The solar field has to be in full operation, make sure there is no clipping in any part of the overflown solar field at the time of flight.
All non-operational modules are shown as “open circuit”
Solar field has to be clean. Solar field cleanliness > 0.97 (less than 3% soiling losses). If soiling is booked in parallel, more soiling can be tolerated.
Only for tracking PV field:
make sure to complete your flights within no more than 2 hours before and after solar noon.
during data acquisition, all module's tilt must be below 30°, results can be compromised for trackers in off-tracking positions. For soiling flights, tracking considerations differ: https://volateq.atlassian.net/wiki/spaces/VKB/pages/4034723871
when actively deviating from tracking algorithms for the flight, make sure to always assure that POA irradiance is higher than 650W/m² (see above)
No shadowing of adjacent rows during flights - especially in winter!
for soiling analysis, there is a checklist here on the additional tasks during flight day: https://volateq.atlassian.net/wiki/spaces/VKB/pages/4034723871

Drone:

Only start the drone at the designated starting point of your flight routes (first waypoint “0” ). Volafly will return a warning if this is not met. Do not ignore the warning.
Make sure the drone settings are put correctly depending on which app you use for flight execution:
Description on how to launch your drone in the VolaFly Drone App: https://volateq.atlassian.net/wiki/spaces/VKB/pages/2989260884
Avoid touching any controller wheel or button during the flight, you might change the camera settings. As a result, this flight cannot be evaluated
Only start the flight with a full drone battery
If solar plant conditions change during flight execution by more than 10% (cloud passage, tracking motor malfunction, curtailment …): pause image acquisition (go to home) and resume after 10-15 mins back in normal conditions
watch drone camera livestream on the screen of the controller and check for sun reflexes or unclear image quality. If reflexes appear centrally in the image you need to counter-act by changing the inclination angle of tracking PV systems or by waiting until the reflex becomes weaker

Additional requirements for IEC 62446-3 compliant inspections

For inspections carried out according to IEC 62446-3, the following additional sensor data must be recorded during the drone flight:

Sensor

Minimum requirement

Notes

Sensor

Minimum requirement

Notes

Irradiance (POA)

Pyranometer or calibrated reference cell in plane of array

Must be logged with timestamp; required to verify >600 W/m² during flight

Ambient temperature

Calibrated sensor in shade, near the array

Required for temperature-corrected module ΔT calculations

Wind speed

Anemometer at hub height or array level

Must remain below 5 m/s; gusts invalidate results

Module temperature (optional but recommended)

Contact thermometer or reference module with PT100

Supports emissivity correction

Logging requirements:

  • All sensor data must be timestamped and logged at minimum 1-minute intervals during the flight window

  • Data to be uploaded alongside drone imagery to the Volateq analysis

⚠️ Without the above sensor data, the analysis can still be performed as a high resolution inspection, but the result will not be IEC 62446-3 compliant.

After flight

Upload data (raw videos and metadata files, not as .zip) to the analysis, via Volafly drone app or via Volateq's WebApp as described here: https://volateq.atlassian.net/wiki/spaces/VKB/pages/2989260884/Volafly+App+Flight+mission+execution#Data-upload
Once upload has finished, use the “Show coverage” tool in the data upload window to check completeness of data. The drone positions should cover solar fields in a regular pattern. See screenshots below
Once coverage has been confirmed, check the box “data complete” as in screenshot further below. From there on, Volateq staff will be informed and will proceed with the evaluation of your analysis.
image-20250526-114726.png
start the coverage check tool

 

coverageMap.png
Example coverage map of a partial data upload. The north eastern field sections have not been covered.
image-20250520-101643.png
Set an upload to complete. Only do once you have confirmed that data is complete

 

 

Further Reads:

VolaFly App: Download and installation

Volafly App: Flight mission execution