Payloads

Everything that is not a camera: hoppers, spray systems, deterrents, gimbals and the mounting that holds them.

Mounting, which is not an afterthought

Every sensor payload needs the same four things, and getting them wrong costs you image quality that no processing can recover.

A printed mount is fine for prototyping and marginal for production. Machined aluminium or carbon plate, with a measured optical centre, is what a survey payload deserves.

Gimbals

Needed for oblique work: orchard fruit counting, vineyard row imaging, and livestock inspection with a zoom camera.

Not needed for nadir survey work, where a fixed downward mount with good isolation is more rigid, lighter and cheaper, and keeps the lever arm constant.

Hoppers, for seeding

See drone seeding for the capability and the mass arithmetic that decides whether it makes sense at all.

Calibrating the spread pattern

Before the first paid job, and again for every seed type:

1. Lay a line of collection trays across the flight path at working height.
2. Fly a single pass at working speed.
3. Weigh each tray.
4. Fit the distribution. That curve gives you the effective swath and the overlap you need.

A coated clover pod and a fine grass seed do not fly the same way, and neither matches the manufacturer's figure.

Spray systems

Read this before buying one. In Germany and most of the EU, aerial application of plant protection products is prohibited by default under Pflanzenschutzgesetz §18, with narrow exemptions, most prominently steep vineyard terrain. Beyond the flight permission, the equipment itself is regulated: application devices are subject to approval and inspection requirements, and the German authorities maintain lists of approved and drift-reducing equipment. A drone spray rig is not exempt from that regime because it flies.

The consequence for a build: do not buy a spray aircraft speculatively. Buy it against a specific customer with a specific exemption and equipment that is recognised for the purpose.

Where it is permitted, the aircraft is a turnkey agricultural machine, not a build project: DJI Agras T25/T50 and comparable platforms from other manufacturers. The nozzles are the interesting part, and they are the same TeeJet-class components a ground sprayer uses.

Deterrent payloads

For bird deterrence. The design constraint is unpredictability, since birds habituate to anything regular.

Check the local nature protection and hunting rules first. Protected species, breeding seasons and permitted deterrent methods vary by German state.

Lights

Weight budget, class B aircraft

Every 500 g of payload costs roughly 10 to 15% of endurance on a 6 kg multirotor. Weigh the payload before you promise a flight time.