Thanks for the advice Makman
You make some interesting points. Mils are something I am familiar with for navigating on land. So mils v deg, I dont mind - they are all numbers
Going back to the reason i started this - I was wanting to confirm I was using the RAOBF the correct way. (I wasnt

) So next was to learn.
This turned out to be quite a trial as I learnt I had wrong cam file after changing the scales etc etc
This has turned out to be a subject that a lot of people have become interested in, new subsimmers and you guys who have a lot of experience in this area.
For me this is great and more people that join in the better.
But all I wanted was to be able to double check differant methods for finding information on a target. So as long as the scales are within a tolerance - thats all I wanted.
For ship information - length mastheight etc, as long as scales of error for each one is constant, then all is ok. I dont intend to go through the whole game correction errors etc. Perhaps others will.
Thanks again for your pointers and a happy new year to you too.