Mobile Operations - The Art of Chase Vehicles For Extended VLOS Missions
Whilst autonomous UAVs are incredibly useful for surveying, they are not totally "fire and forget" in operation - you need to have a flight team to manage the mission as the aircraft performs its flight plan. This is generally because of safety and other flight regulations - once launched the UAV itself is perfectly capable of flying its path and landing automatically.
These flight regulations, the world over, tend to include sections that define how far a UAV can fly from the majority of qualified handlers and remain in compliance. Within the UK - that distance in most circumstances is a VLOS one - Visual Line Of Sight - and extends to 500m. Missions over a larger area than that effective 1km in diameter around the flight team require multiple flights or a mobile operations team.
Planning, Preparation and Mission Modelling
UAV flight management already needs good training and certification and even in a fixed location requires very close attention when the mission is underway. When mobile, that requirement increases dramatically. Planning each stage of the flight is the best first step.
Make allowance for the chase teams to be slower than the UAV. Ensure you have a scout ahead of the main crew to watch for unexpected changes since the initial route checks.
Once the mission plan is in place, there is no substitute for modelling the chase process with the flight team to ensure they have good procedures for any eventualities that could arise. Safety is aided by sensible preparations - watching and listening to procedures for communication amongst vehicles and team members will help standard flight operations to become more second nature and leave the team more capable to meet the challenges of a changing situation during the real flights.
For The Road
Careful vehicle selection and preparation is needed to mitigate the risk of mechanical issues during the missions. Larger cars to carry spares and ancillary crew members are handy, but open-topped vehicles afford the flight team much better all-round views.
Good driving skills and well defined communications procedures are essential.
Roving tests with the chase crews and the flight team are important. Checking the route for GPS and telemetry interference gives the opportunity to observe the moment-to-moment conditions and plan ahead for any problem locations.
On The Road - Manage Mission Leg Distances
"Fly - loiter - fly" is the best mechanism when laying out a flight-plan - pick air locations for loitering the UAV that match ground points for temporary static pilot positions with good visibility for the next flight leg.
Keeping a contingency charge percentage in the UAV batteries during stage planning is important for normal missions - doubly so for mobile ops, where ground conditions for the chase/flight teams could necessitate an extended loiter.
Mobile Ops certainly has its hazards - but these can be mitigated and the advantages are longer range surveys with fewer mapping flights.
Important requirements are:
- Fully planned, team-modelled and manageable flight legs - with dry-runs for all involved teams.
- Capable vehicles and drivers - including wide visibility options for the actual pilot/commander crew.
- Prior route runs to familiarise chase crews with ground conditions and to assess potential interference issues.
- Good communication procedures - cover as wide a range of possibilities and test them thoroughly during dry-runs.