Hi,

After a lot of research, I need for my use in internal of my company the mathematical formula to compute real temperature from Raw value obtained by DJI Thermal SDK tools. I've started to writte my own software to analysing pictures realised by this Drone.

I need to be able to gives somes parameters (RAT - Related Ambiant Temperature, Reflectivity, Object distance, relative atm humidity and temp, and all that is needed to obtain precise temperature used by the Mavic pro entreprise dual advanced to compute the measured temperature).

I've yet written some software for others thermal camera et drones, but, I do not find a lot of real technical informations about the M2PEDA. My ohers software uses FLIR complex formulas, but I can read everywhere that this new drone do not uses the same thermal core components.


For now, I can treat radiometric JPEG to RAW data and display the raw data in grayscale relative colors.




I've already played with formula's like "T_K= (B / Log(R1/(R2*(S+O))+F))" but I need also to find MPEDA constants (Planck R1, Planck R2, Planck B, Planck F, and the Planck O constant).

If someone of DJI's team can gives some technicals informations to compute the real temperature from the raw value, I will be glad to tell me how precisly compute that.


Many thanks,


Best regards,

Hi, we are currently exactly at the same stage... No idea of the equation used for raw--> temp conversion. Worse, the 'dji_irp.exe' included in the SDK does not work well: the '--emissivity', '--distance', '--reflection' and '--humidity' commands cause errors.. No way of tweaking those parameters.

I hope someone from DJI will react!

Unfortunately, you never reach the technical people at DJI through this forum. All you get is the forum adnibistrators who are not even slightly technical and simply spout non-technical answers.

SDU Posted at 2-2 13:04
Hi, we are currently exactly at the same stage... No idea of the equation used for raw--> temp conversion. Worse, the 'dji_irp.exe' included in the SDK does not work well: the '--emissivity', '--distance', '--reflection' and '--humidity' commands cause errors.. No way of tweaking those parameters.

I hope someone from DJI will react!

Hi,

I am still writting my own software, and the command-line tool I've written for now can extract temperatures with success, but effectively, changing parameters (Emissivity, distances, etc) seems to be buggy even with the given compiled libs.

I really hope DJI will post the mathematical formula to perform computation from raw sensor values.

I continue to write a library that can export temperatures to FLIR Studio format. I have to manually rewrite JPEG APP1 FFF format encoding, because the FLIR Atlas SDK seems to do not allow to create new pictures from RAW values (by reverse computation from real temperatures). I will make some other tries with theses libraries later, but I think I will speeder write a full JPEG APP1 FFF segment encoder.

I will post when the final tool will be avaliable and tested.

Best regards,

And thanks for your help.

FrenchUav42 Posted at 2-4 02:06
Hi,

I am still writting my own software, and the command-line tool I've written for now can extract temperatures with success, but effectively, changing parameters (Emissivity, distances, etc) seems to be buggy even with the given compiled libs.

Hi everybody,

I am stiill working on the software between other stuff, and I have successfully developped the tool I want. I continue to perform some mathematical improvement, there are some little degrees differences, but, I can now make a FLIR Studio compatible FFF R-JPEG with a picture taken by a M2PEDA.

The picture taken with the DJI Thermal Tools :


The same once converted with my software:


You can see, there is a little imprecision arround the temperature, but, the pixel clicked on the measure spots are peharps not strictly the same.

For now the tool convert pictures at once, but is designed to perform batch computation, and later again, be able to build batch reports, and getting maximum and minimum points.

I will post again when all theses functionnalities will be done and avaliable to everyone.

Best regards,

Ludo

FrenchUav42 Posted at 6-27 07:48
Hi everybody,

I am stiill working on the software between other stuff, and I have successfully developped the tool I want. I continue to perform some mathematical improvement, there are some little degrees differences, but, I can now make a FLIR Studio compatible FFF R-JPEG with a picture taken by a M2PEDA.

Excellent!