Instructions for merging multispectral projects or merging a multispectral project with an RGB project so that the reflectance maps align with the RGB orthomosaic.
The full workflow for merging projects in Pix4Dmapper is described in How to merge projects article.
However, the difference for a multispectral project is that the MTPs need to be marked in each band for each image, e.g. if the MTP1 is marked in an image of the Green band, it will also have to be marked in the Red, Red edge and NIR images that correspond. Hence, what would be one mark in an RGB project results in four marks in a multispectral project (if there are four bands). In addition, you have to mark your MTP in at least three sets of images. Therefore, there should be at least twelve (3*4marks) for each MTP in the project.
Once all MTPs are added, click Menu Process > Reoptimize to apply the changes.
Pix4D supports only one set of radiometric calibration target images.
In order to get merged reflectance maps, we recommend unselecting duplicate parameters as mentioned in Step 8 of the How to merge projects article.