Help with Creating Time-Aligned Multivariate Data Using IMU and Microphone on a Drone

[etayar]

Hello iNAV community,

I am working on a project where I aim to create multivariate time-series data by combining the IMU black-box data from a drone with sound recordings captured via a microphone.

A key requirement is ensuring that the integration is achieved through a physical configuration where the IMU and microphone data are precisely aligned in time when fused together.

Does anyone have experience or suggestions for hardware setups, synchronization methods, or tools to achieve this? Any tips or references to similar projects would be greatly appreciated!

Thank you in advance for your insights!

[sensei-hacker]

Are you going to make the recording in the future, so you can create a synchronization signal, or are you working with past recordings and have to sync based on what you already have?

How far apart are the microphone and the drone? If the mic is on the drone that's one thing. If the mic is 500km from the drone that's quite different.

Assuming that the mic is close enough to hear the drone power on, typically there will be a series of beeps as the drone arms, followed by the sound of the motors spinning up. The blackbox log also has marker for when it arms. Aligning the "armed" marker with the sound of the arm beeps would be a first step.

You could then fine-tune by matching increases in throttle with increases in the sound of the motors.

[etayar]

Hi, thank you for your response.

I am designing a future experiment and plan to mount the microphone directly on the drone. I focus on determining the optimal physical configuration and ensuring seamless data integration.

[sensei-hacker]

In that case, one could put beep mode on a switch, then check whether that's included in the modes field of the log.

You could either engage beep mode occasionally with the switch, or use the Programming tab to make it beep for one second, pause for 59 seconds, beep for one second, in loop. That would allow you to compensate for timer drift, re-syncing at various points.

[etayar]

Thank you.