Problem i see in flying a drone and taking a pucture of the feild after its been baled is that "here" we uslly start baling after dark when we get some dew on the hay. We also when running a couple of balers at the same time we like to have the stacker running at the same time in order to keep up with the balers and not have to work in the 100 degree heat picking up bales.  I would think some one should be able to come up with something simple that would put mark or spot (rock, tree etc) on a map when ever the balers makes a tie.  Im not really too concerned with how much the bale weighs but more interested in when it makes a bale.  the weight of the bales shouldnt change much from baling 2 ton to ac to only makeing 1 ton.  I have some older 500 ez guide monitors that would work I would think. doing it manual  everytime the balers beeps that it is making a tie wouldnt work cause that would be much for some of my guys to remember to do.