See if this helps.
I'm going on the the 10ft by 100ft = 1000sq ft.
This will probably be a base to go up or down.
I believe once you have your ground speed and times to cover 1000 sq ft. flow calibration should be easier.
Your rig moving 1.14 mph will cover 1000 sq ft in 60 sec.
Your rig moving 2.28 mph will cover 1000 sq ft in 30 sec.
and so forth.
Now spray volume.
assuming all nozzles are the same flow.
calibrate one nozzle for 20 sec then multiply by 3 to get GPM.
then multiply by 7 to get full volume per minute.
so for instance if you are getting .25 gallon in 20 sec = .75 GPM
multiplied by 7 = 5.25 GPM to high for foliage app.
So if you were traveling at 1.14 mph you will apply 5.25 GPM per 1000 sq ft.
If you were traveling at 2.28 mph you will apply 2.63 GPM per 1000 sq ft.
one mile = 5,280 ft. there are 52.8 100ft sections in one mile.
dividing this by 60 sec = 88ft per sec.
60 sec divided by 52.8 = 1.136 or 1.14 mph to travel 100ft.
I hope this helps you.