FlightRecord: Altitude resolution, RTK accuracy and samplingRate

[HeltDav]

Dear DJI Developer Team,

I would like to request some information regarding the following questions:

1. Is it possible to extract the FlightRecord information with a samplingRate faster than 10 Hz? For the Matrice 300, the internal TimeSync should provide most of the included information with at least 50Hz.

2. Can the flightRecord parser extract information a) Whether the drone was using RTK-Network corrected coordinates to navigate. b) Whether the stored "aircraftLocation" variable uses this more accurate position.

3. Could you provide a fix, so that the altitude variable not only contains one decimal place, but uses the available RTK-network corrected altitude which should have an accuracy of around 0.02m and an even better resolution.

Best regards and thanks in advance David

[dji-dev]

Agent comment from xiaorong.zheng in Zendesk ticket #100337:

1. Apologies, but the FlightRecord information is currently being written by the drone itself, and we're not planning to adjust the frequency of writes at this time.

2. a. We're sorry, but the current FlightRecord does not have the capability to determine whether RTK has been utilized by the drone.

b. The aircraftLocation already stores latitude and longitude data. Are you suggesting that the accuracy might not be sufficient for your needs?

3. Our apologies, but it's the drone itself that generates and writes this FlightRecord data. The FlightRecordLib simply takes care of parsing it; currently, it doesn't support using higher precision data than what the drone provides.
   

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[HeltDav]

Thank you for the reply!

Regarding 3: The precise altitude is very important for us. To my understanding the altitude is available with higher accuracy (and actually also with higher precision!). So it should be possible to parse this information to the flight log data (and image meta data).

(from M300 RTK specs): RTK Positioning Accuracy When RTK enabled and fixed: 1 cm+1 ppm (Horizontal) 1.5 cm + 1 ppm (Vertical)

• Can you improve the parsing please?
• Why has it only been written in a resolution of 0.1 m so far?

[dji-dev]

Agent comment from xiaorong.zheng in Zendesk ticket #100337:

Apologies for the inconvenience, but the FlightRecord design is meant to parse flight paths for all types of drones. Since not all drones come equipped with RTK capabilities, higher precision isn't currently supported. Can you tell me more about what you're looking for? There might be alternative SDK solutions that can cater to your needs.

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[HeltDav]

Thank you for the clarification. I understand that there are no plans to improve the time resolution and parsing accuracy of the flight log's latitude, longitude, and altitude values.

Which SDK solution would be most suitable for extracting/storing information with max. speed (>=50Hz)?
More specifically the information of:

• image trigger flag (0,1) and video start/stop trigger time flag
• gimbal angles
• RTK location (lat, long, alt, RTK yaw information)
• x,y,z velocity
• ...

In general, I understand that the internal clock runs up to 400 Hz, min. requirement would be 50Hz for the above information (following this article RTK information is only send with 5Hz to a payload sdk)

[dji-dev]

Agent comment from xiaorong.zheng in Zendesk ticket #100337:

The Payload SDK is likely to meet your needs, but do take note that it's not compatible with every single model out there. Before you jump into using the Payload SDK, swing by the documentation that lists the supported products to ensure yours is covered: https://developer.dji.com/doc/payload-sdk-tutorial/en/model-instruction/choose-hardware-platform.html

By the way, if you're working with the Payload SDK, you'll be happy to know that subscription frequencies can exceed 50Hz. For a comprehensive walkthrough and exploration, feel free to explore the Payload SDK tutorial resources available at: https://developer.dji.com/doc/payload-sdk-tutorial/en/tutorial-map.html
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