Maps or orthophotos may be used in RAMMS, you just need a .tif file and the appropriate .tfw file (world file).
To create the .tif and .tfw file with ArcGIS follow these steps:
- Select File > Export Map... and the 'Export Map' dialogue pops up.
- Type in the name for the map or orthophoto and check the 'Write World File' option. ArcGIS creates the .tif and .tfw file with the name you typed in.