what does "field ratios" means in AM broadcasting

Does this help?

h**p://edocket.access.gpo.gov/cfr_2004/octqtr/pdf/47cfr73.132.pdf

Hi, nimue.
Thanks a lot for your reply!
I think I still have some confusion between filed ratios and the weights of array element.
For example, given two towers' geometry and field ratios:
1, Height(Deg) 90 Spacing(Deg) 0 Field 1.0 Phase(Deg) 0
2, Height(Deg) 120 Spacing(Deg) 90 Field 0.8 Phase(Deg) -90
The base current ratio, base voltage ratio, drive point impedances and power distribution need to be calculated.
So the field ratios is the radiation field in a given point and normalized by tower 1?