Since 2015, Quality Counts has led efforts to collect data for the transportation industry using drones. These innovative devices are capable of capturing thousands of hours of 4k video and ultra-high-definition imagery for a variety of survey types.

We often get questions about our drone capabilities, so this write up offers an overview of how drone services work and how they can be used in the transportation space.

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WHAT IS A DRONE?

For those not too familiar with drones – they are, in short, flying cameras. They have several components reliant on one another to take off, position themselves, record data, and return to their deployment point. This includes a variety of sensors and safety features that address things like obstructions or radio-frequency interference.

HOW ARE DRONES REGULATED?

The FAA has largely struggled to keep up with commercial implementation of unmanned systems in our airspace, but they have made some great strides over the past two to three years. The Part 107 license is a fairly general and easy to obtain certification that allows businesses to use drones for commercial purposes. It doesn’t guarantee the person holding the license is experience and knows the equipment or flying techniques well enough to collect data. It’s simply a baseline credential that every pilot needs to have. In case you were wondering, QC pilots do indeed have their Part 107 certification. LAANC, or Low Altitude Authorization and Notification Capability, is the most recent advancement for using drones in busy urban airspace. It allows pilots to coordinate flights directly with the same people coordinating aircraft, permitting our team to fly in areas that were previously subject to a 90-day manual review by FAA. In other words, on-demand drone flights are now available almost everywhere, and there are some drone airspace mapping applications on the market that make this process a breeze.

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ASSUMING YOU HAVE PERMISSION, HOW HIGH CAN YOU FLY?

We stay under the federally mandated 400-foot flight level. We also only fly during daylight hours, as it’s federally required to maintain line of site of the drone. We’re exploring applying for waivers that will allow us to fly in low-light conditions, but we don’t have them at this time.

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DO YOU MANUALLY FLY DRONE MISSIONS?

Not normally. When everything is lined up and pilots are ready to deploy, there are generally two methods we use to collect data. The first is the creation of orthomosaic images. This is where we define a survey area, use drone deployment software to create a flight plan, and the drone takes off in a completely autonomous fashion. As the drone flies along the flight path, it takes high resolution images about every three seconds. After surveying is complete, you’re left with a massive set of photos that are stitched together to provide a final orthomosaic image of the entire surveyed area. If you’re using a real-time-kinematic system or ground control points, you can get the spatial accuracy down to sub-5cm.

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WHAT IS THE OTHER METHOD?

The other approach is to collect data using tethered surveillance. A tether is basically an extension cord attached to the drone and sends it power from a generator. Most systems are limited to 200-300 feet. A deployed system is fairly inconspicuous and will result in a vantage point unparalleled by any other technology on the market.

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WHAT ABOUT FREELY FLYING A DRONE?

We can, but we prefer not to. Free-flying requires hot swapping drones out to maintain continuous coverage of a survey area. This requires additional pilots and equipment, which costs our clients more as a result. It’s only okay in cases where a client wants maybe 15-20 minutes of coverage of an area, perhaps during the peak 15-minutes of a study area.

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HOW DO YOU PROCESS DATA COMING FROM DRONES?

There are options for both manual and automated data depending on what you’re looking for. DataFromSky, GoodVision, and Brisk Synergies (now Transoft Solutions) are a few examples we’re familiar with. The principal of what they do is essentially the same – they provide per vehicle object trajectory data at intersections and along corridors. The downside of automated processing though is that objects that are tracked need to maintain a particular pixel density to be detected. So far, what we’ve seen is that most software can accurately track vehicles up to about a quarter mile before accuracy declines. With manual processing, our team can count much farther – quarter to a half mile depending on roadway geometry.

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WHATS THE POINT OF TRACKING OBJECTS?

There are lots of reasons. Tracking an object allows you to look at its speed, headway, acceleration, gap, and an assortment of other variables. One end result is that you can do things like conflict and safety analysis on roadways by assigning values to potential collision risk. This allows you to create before and after insights for safety evaluations without relying on inconsistent or under-reported crash data.

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ARE THERE OTHER USES FOR DRONES BESIDES SAFETY ANALYSIS?

Absolutely. We can do complex intersection TMCs, parking studies, queue studies, before/after site mapping, and school operations studies, to name a few. Those same studies can also be performed with helicopters and fixed-wing aircraft if the study areas are particularly large, both of which we have access to through some of our data collection partners.

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IS THERE ANYTHING ELSE ENGINEERS SHOULD TAKE NOTE OF BEFORE DOING A DRONE PROJECT?

In short, it’s better to trust a data collector to fly a drone than to trust any pilot to do accurate data collection. Everyone and their mom, nephew, and cousin seem to have a Part 107 nowadays. Having that certification doesn’t guarantee sufficient collection for accurate, reliable data reduction from the video or imagery collected. I can’t vouch for other data collection firms but I would trust them over hiring any freelancer, as they have experience from other studies knowing what vantage points can and can’t be accurately reduced through manual or automated means. Additionally, it’s their reputation on the line, so there’s extra incentive for data collection firms to get the work done right the first time.

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