Hi Boreas
I assume you're trying to generate a sat map from an existing ArmA map. That being the case I think you're out of luck.
A 1 piece sat map (with any resolution) doesn't exist for most if not all BIS supplied ArmA maps.
What you will find is a mozaic of bits that make up a map.
For example, Rahmadi is found inside "desert.pbo"
Inside that you will find a directory called "data"
Inside that you will find many files, but the many sat map bits have a file name like "s_003_002_lco.paa"
These bits actually overlap each other, so its not even simple to peice them together.
Inside 1 of the pbos theres a Sahrani map 1 peice texture, but its only small as its used to attached to the "map stand" object.
In community made island made addons, the maker may have left the original large sat map inside the PBO, but it thats not guaranteed.
For Sahrani there are 2 downloads from community made custom sat and topology maps;
http://www.armaholic.com/page.php?id=1985http://www.armaholic.com/page.php?id=1167