About reflectance panel and radiometric correction

Agriculture
1

Hi
I used the sequoia panel to calibrate the image taken by DJI multispectral camera.
But Pix4D fields sent out this message.

‘‘Reflectance targets were found, however, the reflectance factor could not be determined for all bands. Performing radiometric correction without reflectance targets.’’

what’s the problem?

2

Hi,

This is caused due to the lack of blue band in the sequoia camera, I guess the reflectance panel doesn’t have it either. So when trying to calibrate all bands from P4M, blue is missing.
Also read “The Parrot target does not report reflectance values for the P4M bands. You need to measure them yourself. First, measure the spectral reflectance factor with a spectro-radiometer. Then you need to know the spectral sensitivity of the P4M bands, and using that you can compute the effective nominal reflectance value of the Parrot target for the P4M bands” stated in this thread

Best.
José

3

Thank you Arnaudo.
Then, can you recommend another calibration panel?
Is it possible to correct the radiometric information of other companies’ panels?
e.g. sentera or micasense?

4

Correct, Micasense or Sentera could be used.

Best

5

Hi Jose, just to confirm, if we use calibration panel from sentera or micasense there will be no problem in processing P4M image in pix4d? For the result, is it sufficient enough to be used in plant monitoring? thanks

6

Hi,

Yes they can be used for plant monitoring.

Best,