7 Tips for Successful Drone/UAV Operations in Cold Environments
Whatever the application around the world, be it mining, engineering, research or agriculture, in general terms small mapping UAVs are being increasingly utilized to observe the Earth’s surface in great detail - to monitor change over time. The analysis of this data enables better decision-making, resulting in increased efficiencies and cost savings to its adopters.
To do this efficiently and effectively in many locations, the technology and its users must be capable of operating all year round - effectively in either hot or cold environments. In this article we will look at some of the capabilities and disciplines required to operate in cold environments.
Cold sub-zero temperatures, wind-chill factor, snow and frozen solid ground are just some of the factors that make UAV operations in cold environments one of the most complicated tasks. Combining cold ops with a demanding flight schedule ? It does not get tougher than this.
To operate in cold environments, there a number of crucial operational factors to consider:
1. A well-trained and disciplined crew is worth their weight in gold:
Freezing temperatures and wind chill will significantly reduce the efficiency and performance of the team and equipment.
A well-trained, well-rehearsed and experienced team who understand the effects of low temperatures on both the crew and the equipment is key. Training, crew preparation, cold ops risk assessments, and equipment preparation for cold operations will best prepare the team and develop efficient workflows and procedures to mitigate risks to the mission.
Live mission simulations at the training site will pay dividends in understanding performance of UAV and crew in low temperatures - remember training is the best insurance policy as it focuses on learning new skills in a safe environment where there is the space and opportunity to safely make mistakes.
Live ops has limited scope for learning and focuses on data acquisition rather than UAV team building, cooperation and efficiency.
For crews, at zero degrees everything takes twice as long to complete, compared to +10°c operations. At -10°c everything takes at least four times as long. Crew roles and organisation becomes critical in the fight to prevent UAVs becoming cold-soaked during pre-flight preparations.
Remember – a well-trained team, combined with a well-planned mission will result in a safe and successful data collection.
2. Battery Performance
Small Mapping UAVs, on-board sensors, ground control laptops and transmitters are predominantly powered by Lithium polymer batteries (LiPo). It’s a fact, LiPO batteries are susceptible to performance issues when operating in cold environments. To combat this issue, many UAVs now use temperature sensors to warn the operators when a critical external temperature has been reached, triggering safety mode and disabling flight. Whilst this is a great safety feature, this presents a huge issue for businesses and research institutions that have time critical data requirements in cold environments.
At QuestUAV, we believe that the users must be able to dictate their own flight schedules in all environments. By implementing strict procedures and guidelines, the operators are able to get full performance from their UAVs in cold climates. Understanding the technology, the environment, utilizing a combination of on-board climate monitoring sensors and thorough pre-flight and in-flight checks, flying at sub-zero temperatures is an everyday reality.
Mobile ops vehicles need to prepared for safe transport of crew and equipment - all organized for efficient and rapid deployment. A 300w 12volt inverter is essential as power supply backup. Aircraft set-up/configuration correct for mission - Example: corridor mapping ‘point and click plan’ – use the gimbaled sensor Q-POD for the Q-200. This enables vertical mapping of the target whilst the UAV is in a bank - the UAV will bank on planned turns and in high or gusty winds. For Grid Plans – use the non-gimbaled sensor Q-POD, more robust and simple to use.
Keep UAV in Warm controlled environment (out of wind), vehicle or heated ops tent. Use spare LIPO and camera battery for pre-flights, insert fresh pre-warmed fully charged batteries prior to launch. Keeping batteries in coats or near heaters in vehicle can help to keep them warm. Ailerons hinges - Exercise ailerons pre start, ensure free moving and not ridged from severe cold. Remember at high altitudes the temperature will be colder – falling -1 degrees per 400ft)
Monitor flight time and battery voltage, if battery drains rapidly due to insufficient pre-warming, recover UAV and solve the issue. For example, replace freezing batteries with pre-warmed batteries and resume mission.
Out in the field, transport, mobile ops set-up, crews, efficient workflows, tools and spare equipment, documentation etc. are critical. Experience will continuously inform and advance operational capability, as long as crews adhere to their training.
- Make sure all spotters are well briefed, including full safety card procedures, locations and telecoms etc.
- Crew preparation - Trained, fully briefed on all stages of the mission, on-time and kitted out for cold ops.
- Use all available resources including additional spotters if you can.
- Re-evaluate risk assessments in cases of crew and spotter changes.
Desk Study, Risk Assessments, 48hr Checks and UAV Base-Checks must be fully understood and systematically completed and documented. All crew fully mission briefed, crew roles and hierarchy firmly established. Remember last minute crew changes carry high risks that require teams to either mitigate the risks or potentially cancel the operation.
Remember your operations documentation and video your missions for post flight analysis and crew training – it is very important!
4. Field-serviceable technology.
Spare and repair equipment is essential for all operations. Remember in cold operations the crews will have limited ability to repair on-site, however spare components are required to succeed. Landings are tougher on a cold UAV airframe, most materials become more brittle as temperatures fall - causing increased risk of damage through the fracturing of cold materials. Sustained exposure to the cold whilst handling equipment and fine electronics can lead to rapid crew inefficiency or incapacitation. In cold environments, field repair capability is limited. Normal tapes no longer adhere and glue repairs don't set. Airframe EPP foam will experience shrinkage, wing surface laminates will slightly wrinkle and increased prone to cracking. EPP becomes solid, doesn't compress and therefore transmit increased landing shock through the UAV. Gimbals become tighter in the EPP body.
Remote operations in cold environments require task specific spares. Pack cold ops spares.
A good sized vehicle is important for UAV pre-start warmth, crew protection, UAV ops, keeping batteries, laptop and transmitter warm, carry spares. Alternately use a 4m x 4m heated operations tent kept at 10°c (Electric or gas radiator heaters)
5. DATA – what it's all about!
After all the fixation on the array of aerial data collection vehicles available on the market, weeks spent scrutinizing specifications and deciding which one fits your needs, essentially UAVs are there to carry a sensor to capture accurate, quality data. So what about the all-important DATA and how can cold operations affect it?
Usually, there is less light available at all stages, resulting in small flight windows. Also, remember low light will have a negative effect on your image quality.
In addition, unbroken snow can prove problematic when processing your data - similar to difficulties with mapping water bodies.
For the operations team, everything must go right to be safe and successful - make sure they understand and follow all cold-weather procedures.
6. Flight Planning.
Assess target area and weather. Visit site if possible, carry out full desk study and 48hr checks. Calculate flight time, factor in potential loss of endurance due to flight plan altitude, temperature and weather.
Avoid planning a downwind position of UAV at end of flight, batteries will be low and fighting against wind will not help.
Equipment Preparation - Full base checks. Use a shadow board.
Remote operations in cold environments require task specific spares. Pack cold ops spares and UAV in one vehicle.
Send planning documents to QuestUAV or your technology partner for pre-ops analysis.
7. Technology Partner
Finding the right equipment for the job is crucial. Understanding the equipment and your roles in deploying it are equally important. Harsh environment proven systems and accompanying workflows are a basic requirement and a technology partner that will support you directly is often overlooked and plays a pivotal role in successful application of the technology.