I have several single band raster layers in my ArcGIS Pro project which cover a large area; these are 1-band Red, Green and Blue reflectance layers; and I have 10 layers for each colour (30 layers in total). These layers when put together cover a continuous geographical area. I first used the Merge Rasters (Data Management tool) to merge them; this created 3 layers covering my area. Second, I used the Composite Bands (Data Management) tool to use these 3 layers to create a single RGB layer. This worked well and the result was great. However, when I re-opened the project later the merged layers and composite band layers are no longer on the map: they are in the contents pane but they have a missing data source. However, the original single-band rasters are still in the map without a broken data source.
My question is, how do I merge layers, and create composite band layers, and actually keep them in the project for the long term without them getting a missing data source?
Thank you in advance for any help.
