Support Website Contact Support Blog

MAPIR Reflectance Calibration Ground Target Package

Hi Support,

The MAPIR package has three ground targets (color cards) that report the values 87% R, 51% R and 23% R. To calibrate the bands in Pix4D Mapper should I report 0.87, 0.51 and 0.23 as albedo values?

Is it sufficient to perform the calibration of the images in the Pix4D Mapper or do I have to use the MCC software they provide?

Please help me solve this problem.

Hi, Walter,

If by colour card you mean the calibration target ( the one presented here) you could use it as a calibration target for radiometric corrections in the software or I see that you could use it for post-processing in MCC. If you use it in our software then you should pick the one that has the profile closer to the reflectance you expect in your field.

For more information or step by step instructions on calibration target see: Radiometric-Calibration-Target

Cheers,

Ina

Hi Ina,

I thank you very much for your guidance…

but I need to know if I can use the values provided by the MAPIR radiometric target (87% R, 51% R and 23% R) by entering these albedo values (0.87, 0.51 and 0.23) in the Index tab Calculator to calibrate the bands.

I sent an e-mail to MAPIR and received this information: “We do not recommend using Pix4D for calibration since they only support a single target for calibration. We recommend running the orthomosaics through our MCC calibration process. If you still want to try using the albedo values you can look at the peak value in the target datasheet. The albedo values should be the peak reflectance at the peak of the transmission transmission wavelengths. The% R means that is the average reflectance value for that target material. We don’t offer support outside of our MCC application, sorry”

I’m new to PIX4D and I’m asking for your help to solve this problem… Forgive me.

Hi Walter,

As previously mentioned you could use this target with our software, I am not familiar with Mapir’s workflows and also not sure what does exactly is referring to multiple targets.

Given this could you please let me know what exactly the pre-processing of MCC is consisting of?

Thank you,

Ina