Two other recommendations:
1. This may be what you're using and having a hard time with, but use the lower images in the recognition guide to help figure out the AOB if you're forward of the beam.
2. In the SH3 Mods section is a tool that may help as well. I've downloaded it, but have not used it yet.
http://www.subsim.com/radioroom/showthread.php?t=123373