Drone for mapping and counting weeds

I am working with a grower who wants to use drones for a specific purpose. We are trying to identify what hardware (drones) would be best suited for his needs.

What he wants is to use a drone to count weeds in the field. His average field sizes are between 60-120 acres and the images would need to have a resolution high enough to detect early-growing plants (maybe as small as 1/4" in size).

I think it is obvious that mapping an entire field with this type of resolution would be impractical. Therefore, we were thinking of taking randomized samples (pictures) of the field in different areas to generate an “average # of weeds per given area”.

Along this line of thinking, we were considering what drone would be best suited for his needs. On one hand, he could buy a really expensive drone with very good resolution and fly at a greater height. However, for the same cost (or even less), he could buy 10 “cheaper” drones, fly them at lower altitudes but still accomplish the same objectives (“10” might be an exaggeration, but there to make a point).

Any thoughts or ideas on this?


About 90ac would be 3-4 batteries with Phantom 4 Pro at 150 ft to get 0.5in/px. I wouldn’t go any smaller than that. I would also look at a Yuneec H520E. They are about 2.5x the cost but have a lot of advantages with camera selection and form factor.

Thanks Michael,

When you say not to go smaller than that do you mean you wouldn’t fly lower, say at 75ft to get ~0.25in/px? Or smaller as in camera/drone model?