Radiometric calibration panel in the Netherlands

Agriculture
1

Hello,

I have a DJI Mavic 3M, and will be mapping tulips and peonys. For accurate results I want to calibrate the radiometric reflectance, but it is hard to find a good reflectance panel. The Micasense and Sentera are compatible with the drone, but the Sentera isn’t found in my country, and the Micasense is expensive.

Is it needed to calibrate for accurate data and comparison between flights?

Greetings,

Mees

2

Hi,

You can find more info here: Radiometric correction - PIX4Dfields

When comparing overtime, it would be interesting to use a reflectance panel.

DJI Mavic 3M:

  • These cameras are not fully radiometrically calibrated, only a relative calibration is done by the manufacturer: All bands are calibrated against the standard NIR band. Therefore, the cameras will not provide reflectance factors, but only relative values proportional to reflectance.

  • A reflectance target is required to obtain reflectance factors. Only Micasense and Sentera targets are compatible with the DJI P4 multispectral and Mavic 3 multispectral.

  • Without such a target, only self-normalizing indices produce meaningful results, i.e. indices that don’t depend on the absolute value. Examples of such indices are NDVI, NDRE, VARI, SIPI2, LCI, BNDVI, and GNDVI. Not self-normalizing are TGI and MCARI.

1 Like
3

Hello,

I use the DJI P4 multispectral drone and the Mapir calibration panel before each flight. Unfortunately, I found out that this panel is not supported by Pix4Dfields. Is there any method to solve this problem? Is it possible that on some dates, negative values of NDVI (for field parts covered by crops) are caused by the lack of radiometric calibration while using Pix4Dfields? Will the use of Pix4Dmapper solve this problem?

4

hi,

We can’t confirm that using the reflectance panel in PIX4dmapper will solve the problem. Negative NDVI values can be caused by under- or over-exposed pixels, incorrect camera sensitivity, or other factors.

You can try processing again disabling Radiometric correction in PIX4Dfields.

5

Hi, Thanks for your help.

6

Hi,

Which reflectance panel would you recommend to purchase to be successfully used for radiometric correction, both in PIX4Dfields and PIX4dmapper?

Stanislaw

7

Hi, the question is, what drone are you using? You can find more information about reflectance panel here Radiometric correction - PIX4Dfields

Long story short, micasense and sentera panels are suitable for most drones.

8

DJI P4 Multispectral