How accurate are your UAV surveys?
The accuracy of a UAV photogrammetry survey is generally constrained by the accuracy to which the Ground Control Points are surveyed. So accuracy can be as good as a ground-based GNSS RTK survey, of the order of 30mm in plan and 50mm in height. More information can be found on our Accuracy page.
Are you restricted by weather conditions?
Traditional surveys can be deferred or cancelled because of weather conditions. Weather may also prevent a UAV survey from taking place on a particular day, and so we try to schedule surveys for times when flying conditions are likely to be favourable. However, data acquisition with a UAV is so fast and efficient that we can generally find a window of opportunity even on a poor flying day, allowing the survey to be completed despite the weather. We can fly in winds up to 17mph, and in drizzle or light rain. We can't fly in heavy rain or snow, as heavy precipitation blocks the UAV's control signals.
How large an area can you cover?
The area we can cover in a day depends on the resolution needed in the DSM and orthomosaic. The finer the resolution required, the longer it takes to cover a given area. Typically, we expect to cover up to 120 ha in a half-day or 250 ha in a full day's flying. The largest area we can cover in a single flight is around 75 ha, so if the survey area can't be covered in a single flight, we simply break the survey up into a number of back-to-back flights. We always carry a large number of spare batteries for our UAVs, so it's an easy matter for us to land to swap batteries, and in a matter of a few minutes we can be back in the air surveying the next segment. This allows us to fly from dawn to dusk if necessary.
Is there anywhere you can’t fly?
We can't fly in congested urban areas due to CAA safety constraints. Sites close to airports and airfields are normally out of bounds too, though in certain circumstances we can obtain permission to fly.
Are you insured?
We carry specialist insurance for our UAV operations, including £10m public liability cover.
What qualifications does your pilot have?
Our pilot holds a CAA Permission for Commercial Operation (PfCO), which shows that he has been assessed as a safe and competent UAV pilot, and allows us to legally fly UAVs for commercial work.
Do you follow defined safety procedures?
We perform all flight operations in accordance with the safety procedures specified in our UAV Flight Operations Manual, which specifies safe operating practices to be followed before, during, and after all UAV flights. The safety procedures described in our Flight Operations Manual have been assessed and approved by EuroUSC on behalf of the CAA.