Frequently Asked Questions

Answers to Questions that customers frequently ask

Can you explain what UAV, UAS, RPAS, GIS and other such terms mean?

UAV - is an acronym for Unmanned Aerial Vehicle, which is an aircraft with no pilot on board.

UAS - is an acronym for Unmanned Aircraft System, and is an all encompassing description that encapsulates the aircraft or UAV, the ground-based controller, and the system of communications connecting the two.

RPAS - is an acronym for Remotely Piloted Aircraft Systems. RPAS are not intended to take over all tasks of manned aircraft but they are capable of flying closer to obstacles and are conducting operations that cannot be done by manned aircraft due to the safety risks or the excessive costs involved.

GIS - is an acronym for Geographic Information System, and is a computer system for capturing, storing, checking, and displaying data related to positions on Earth's surface. This enables people to more easily see, analyze, and understand patterns and relationships in one map.

How accurate are your surveys?

Clients who haven't used a UAV before are often concerned about the level of accuracy that can be achieved, we can assure you that UAVs can offer the most spatially accurate aerial survey data currently available. To find out why this is you can read our article here The error of our extracted survey points can get down to around 9mm in height and 6mm in plan with good ground control, and specialised post-processing techniques. For most land surveys we generally work to around 40mm in height and 30mm in plan. The cost of these surveys per unit area does vary and so the higher accuracy you require the more it will cost. It is therefore a good idea to understand what you are trying to achieve and the tolerances you need to achieve it.

Can your topographic surveys provide terrain data under vegetation?

Yes, our LiDAR unit is able to penetrate through the vegetative canopy and directly measure the ground.

What are your flight times?

A typical flight with any of our platforms lasts between 30 and 60 minutes. However, these times vary depending on a variety of factors including the weather, flight characteristics and the camera system being carried.

Although these flight times may not seem like very much, in our experience they are easily long enough to enable us to achieve a great deal. We also carry with us a number of batteries which can be swapped over quickly enough in order to proceed with the flight almost immediately. Furthermore, we have on-site charging capabilities allowing us to always have enough batteries to be able to begin another flight.

What weather conditions can you fly in?

Generally speaking we can fly in weather conditions with winds up to 17mph and no more than very light rain If there are adverse weather visibility conditions (e.g. fog/haze) we may need to alter our flight plan in order to maintain a line of sight with the UAV.

What is the maximum distance and height you can fly?

Bureau Stephan's aircraft are able to fly up to an altitude of 4000m and up to 5 km horizontlly while maintaining radio (telemetry) contact. In some countries we are restriced to distances of 500m from the pilot. This is in order to ensure the UAV stays in the pilot’s line of sight. We monitor the UAV’s altitude and distance from the pilot using telemetry information fed back to the pilot’s screen.

Are you able to operate in congested areas, such as in a major city?

Yes this is possible. Extra permissions may need to be sought when operating in cities or built up areas and this may take weeks to acquire. For safety reasons we would only use our smaller UAV's to execute such projects.

Is there anywhere you can’t fly?

Unfortunately, yes. These areas are typically around airports and sites of military activity. We sometimes also need permission from property owners if we want to take-off or land in certain areas.

What weight can it carry?

Our larger platforms – the Skywalker X8 – can carry loads of up to 1kg, whilst the Sensefly Ebee can only carry 0.2kg.

How fast can it fly?

The maximum speed of the Sensefly Ebee is ___ km/hr
The maximum speed of the Skywalker X8 is ___ km/hr

What fuel do the UAV's use?

All of our UAVs use Lithium Polymer (LiPo) batteries.

How much do your services cost?

Our work tends to vary in terms of timescale and data processing requirements, consequently it is very difficult to quote a standard price as each job is different. Bureau Stephan is always happy to offer a free no obligation quote. We are usually able to give you a rough estimate of costs in a quick phone call.

Please contact us to discuss your aerial surveying needs and we will supply you with a bespoke estimated quote for our services.

Are you legally allowed to do this?

Bureau Stephan recieves written permssion from the Civil Aviation Authority and Ministry of Defence for each country in which we operate. This allows us to operate our UAVs commercially and perform aerial data acquisition. Furthermore, we always operate well within applicable legislation, including international UAV standards and recommendations.

What qualifications and training do your pilots have?

All of our pilots possess Remote Pilot Qualifications for small platforms. This qualification assesses the pilot’s competence regarding the knowledge necessary to become a commercial UAV pilot, including knowledge of aviation law, meteorological conditions and human factors which affect flight safety. To pass this they must also have passed a practical and UAV-specific annual flight assessment. In addition to this, all of the pilots have undergone systems training with the manufacturer and receive ongoing in-house training.

What emergency prevention features do your UAVs have?

As well as our numerous procedures which reduce the likelihood of an accident, our systems all possess in-built emergency prevention features to minimise any damage in the unlikely event of an emergency. This includes low battery voltage alarms, the ability to glide in case of motor failure, and a return to home feature which, if contact with the radio controller is lost, allows the UAV to fly back to its take-off zone at a pre-defined height and land itself.

How do you ensure the privacy of the public and third parties?

As we carry imaging equipment on our UAVs we must adhere to a number of regulations to protect the privacy of the public and third parties. This includes flying the UAV no closer than 150m above populated areas. For safety as well as privacy we also fly no closer than 50m to any structure, vehicle or person without their permission. The exception to this is that we may fly as close as 30m to persons without their permission during take-off and landing.

Can I mount my own camera on your UAV?

No. Bureau Stephan uses specially modified cameras that are tailor made for our fleet of UAV's. Customer camera equipment would likely be too heavy, require special mounting and take inferior quality images.

Do you allow clients to fly your UAVs?

Due to insurance and legislative restrictions, we are unfortunately unable to allow clients to operate our UAVs. This is because all commercial pilots must hold a remote pilot license (see “What qualifications and training do your pilots have?”). However, clients are always welcome to accompany us on jobs.

What regions do you operate in?

As aviation laws differ country to country, we are currently able to offer our services in the all regions where the Civil Aviation Authorities permit licensed UAV operation. Although Bureau Stephan is based in the Dubai our clients and operations are worldwide.

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