This article describes how to plan a mission for solar panel inspection using the eBee X with the Duet T camera and explains the system's limitations.

As specified in the SOLAR 360 RAPTOR MAPS SERVICES – TERMS AND CONDITIONS, the quality of the report will depend on the quality of the data captured. These guidelines must therefore be followed.

Please consult this document regularly as the requirements may evolve with future software development and don’t hesitate to contact senseFly or your reseller with any questions.

Use the Solar Panel Inspection check list attached for all your mission.

Step 1: Prepare your mission

A well-prepared mission is a mission that will run smoothly and maximize efficiency, safety and data quality. There are 2 aspects to prepare:

  1. The PV system information for the analysis
  2. The PV site information for the flight

 

Gather all the information on the solar panel installation you are planning to inspect

Raptor Maps requires all the following information to be submitted via this form for each PV system:

  • Site Name
  • Site Power (MWdc)
  • Site Address
  • Module Manufacturer
  • Module Model
  • Module Peak Power
  • Module Layout (modules per string)
  • Inverters
  • Tracking/Mounting Technology
  • UAS & Imaging System
  • UAS Flight Pattern/Notes
  • As-built schematic drawings

 

Gather information for the flight

To prepare the eBee X flight, you need to pay attention to the following:

  • Check the flight environment. If possible, go on site to make sure no obstacles are present in the flight volume (power lines, cell towers, etc…) and make sure a landing zone is available. If you cannot go on site, use Google Earth and Street View and contact a site technician that knows the site installation very well.
  • Check with the authorities if there are flight limitations or any authorisations needed to use the air space above the PV installation. Be careful in controlled airspace for any maximal flight altitude.
  • Check with the PV asset manager if an up-to-date RGB based map is available for the PV site (TIF format). If it is available, you can import it into eMotion to facilitate the flight planning.

 

Step 2: Prepare the flights

 

1. Create the project

In the office, open eMotion and create a mission with a name that links it to the inspection job. Select the Duet T camera.

1.png

 

2. Get the background maps

Having an up-to-date background map in eMotion will greatly facilitate flight planning. When available, load the orthomosaic and the DSM into eMotion.

NOTE : Don’t forget to download the map data before going on site.

 

3. Set working area parameters

Locate, on the map, the site using the search tool. Set up the required working area parameter, place the center of the working area and then position your home and start point.

 

 2.png

 

4. Create the mission blocks for the inspection

  • On the Mission block tab, place a horizontal mapping block on the area to inspect:

3.png

 

  • Adjust the mapping block's edges so that they fall along the edge of the solar panel installation:

To favor efficiency on a compact installation, create a single block that covers the entire installation (see example below). If the background map is up to date and accurate, there is no need to add a margin around the installation.

4.png

If the installation consists of multi sub-sections spread on the site, create several mission blocks (see example below). You can name the mission block according to the as-built schematic drawings for clarity.

 6.png

 

  • Set the flight orientation parallel to the solar panel rows. Use the flight direction handle to orient the flight line along the solar panel rows as best as possible

 7.png

  • Set up the mission block's parameters as follows:

    Thermal
    Resolution: 5.5 cm/px
    Lateral overlap: 20%
    Longitudinal overlap: 80%

5.png

 

5. Create a mission block for the RGB orthomosaic (recommended)

You can used the Duet T camera to collect the images or any other RGB camera compatible with your eBee X (S.O.D.A, S.O.D.A 3D (NADIR only) or Aeria X).

  • With a Duet T camera
    Create a second block that cover the installation to map with the following parameters:

    Thermal
    Resolution: 11.0 cm/px minimum
    Lateral overlap: 75%
    Longitudinal overlap: 70%

8.png

This will correspond to a 2.0cm/px with 80% lateral and longitudinal overlap on the RGB sensor.

After the flight, discard the thermal images recorded and upload only the RGB images to Raptor Maps to generate the orthomosaic.

  • With a SODA or Aeria X camera
    Create a second block that cover the installation to map. Select your camera with the following parameters:

    Resolution: 2.00 cm/px minimum
    Lateral overlap: 80%
    Longitudinal overlap: 80%

 9.png

You now have all your mission blocks ready and a total flight estimation for the mission. Prepare the necessary batteries and power supply for the ground control station to cover the entire mission.

  

Step 3: Select the day for flight

Now that the mission is fully prepared, you need to select a good day for the flights. Find the most reliable weather forecast to select the day having the most favorable conditions.

The required weather conditions are as follows:

  • No rain, no snow
  • No cloud
    • Specifically, irradiance greater or equal to 600 Watts per square meter
  • No fog
  • Maximum wind of 5 m/s

If possible target a time slot with the lowest wind forecast.

 

Step 4: Perform the inspection on site

Check the weather conditions on site

Using an anemometer, measure the wind speed on site. Based on the wind speed measurement, the following actions should be taken:

  • Wind speed is below 2 m/s: Proceed with the flights at 5.5 cm/px resolution
  • Wind speed is between 2 to 5 m/s : Proceed with the flights but increase the resolution to 7.5 cm/px
  • Wind speed is above 5 m/s : Do not fly

The above requirements are important to ensure the best possible data quality and no data dropout. Strong winds also affect the temperature measurement on the solar panels.

 

When can the inspection begin?

The PV cells must first reach a certain level of natural irradiance to get correct temperature reading. A recommended level of 600 W/m2 is required to ensure any anomalies will be identified.

If the irradiance level is too low, you can first perform the RGB mapping in the meantime.

If the installation is made of sun tracking PV, the angle of the panel must be at 20% minimum.

 

Perform the flight

When the required conditions are met, you can start the inspection of the solar panels. Refer to the eBee X flight check list before launch.

You can track the flight number and the section inspected per flight for further reference.

NOTE : Overlap limitation

Using eMotion 3.7.9, the longitudinal overlap is no longer maintained after a certain number of images taken depending on the resolution of the flight. To avoid data dropout, please follow those requirements:

  • When flying at 5.5 cm/px resolution,  stop the flight every 1'000 images. You can land the drone and re-launch straight away until the battery is too low to take off.
  • When flying at 7.5 cm/px resolution,  stop the flight every 1'300 images. You can land the drone and re-launch straight away until the battery is too low to take off.

 

Step 5: Collect the data after the flights

All the images collected are recorded on the Duet T's SD card. A folder is created for each flight (with the flight number) and contains the RGB images and the thermal images in a separate folder.

You can use eMotion Flight Data Manager to import the data from the SD card to your computer. eMotion will guide you through the import of every flight and ensure that you don’t miss any images.

 

Step 6: Upload the data the Raptor Maps

To transfer images, access the Raptor Maps app and select Upload Images from the menu.

Step 6: Send the PV installation site to Raptor Maps

Make sure that you have provided Raptor Maps with the information and as-built as specified in Step 1.

For more documentation on Raptor Maps please go to https://docs.raptormaps.com/docs.

 

 

 

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