I'm currently on a project in ArcGIS Pro where I want to calculate the RVI of a RS time series collected by Sentinel-1. Unfortunately, I only have for each date one Tif-file for the VH and one Tif-file for the VV polarization. I have them stored in each a local folder "VH" and "VV". Now I use the ModelBuilder to batch process these images. In a sub-model, I iterate over the VV-rasters and clip them to the desired extent. Now I want to include them into the main model, where I iterate over the VH-images. Within this main model, I want to calculate the RVI by using the Raster calculator. Unfortunately, my sub-model VV output rasters can only be used as preconditions, but not as input data. I tried to apply the collect values function in the sub-model and the merge-function in the main model, but this does not work as I can only give the submodel's output as precondition.
Could you give me some advice?