Everytime a starship engaging in FTL travel transitioned back to the material dimensions, a considerable amount of fluctuations burst out from the point of emergence.
While these fluctuations are quite random and chaotic, humanity slowly learned how to decipher a number of clues. By interpreting certain patterns, it became possible to predict the size, mass, FTL drive strength, power output and many other parameters.
The CFA unquestionably developed these capabilities the most. Rumors circulated on the galactic net that the CFA was able to peer into the higher dimensions and make detailed observations of any ships travelling through them far in advance!
Ordinary states and organizations didn't have these capabilities. At the most, their best sensor systems were mostly able to give them a brief advance warning as well as providing estimates on the overall mass of the entering ships and possibly how many of them were emerging at the same.
