Within the defense sector, demand for unmanned air, ground and sea systems continues unabated. Drivers include combat operations, reduced military budgets, a changing national security environment and improved technologies. The chart shows what the DoD has budgeted for the next 5 years.

Hold-ups include a lack of interoperability and modularity; communications systems, spectrum and resilience; security; ability to operate safely stationary; autonomy and cognitive behavior; ability to carry and type of weaponry.

Below are the budget figures separated by air, ground and sea.

Ground systems include bomb detection and disposal, engineering and construction, route clearance, recon robots of all types.

Marine systems include mine hunting and countermeasures, port surveillance, electronic warfare, special ops, hydrographic recon, hull cleaning, sensing gliders and unmanned devices.

Aerial systems include penetrating and persistent (persistent to the military means stationary) data relay platforms and tactical devices. Small tactical devices include micro/mini devices and throwables for reconnaissance.

Source: DoD Unmanned Systems Integrated Roadmap FY2013-2038