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07.17.2014

The Fundamentals of UAVs

At the end of 2013, Jeff Bezos announced his plan to use unmanned aerial vehicles (UAVs), or drones, to deliver Amazon goods from its warehouse to your doorstep.  Some thought it was genius, while most  considered it to be wishful thinking. Nevertheless, the Bezos announcement was indicative of what was comingwhat has come—UAVs as a part of the civilian lexicon. While drones have gained considerable infamy because of their military applications overseas, their utilities in civilian industries are gaining recognitionfast.

The Fundamentals of UAVs

The UAV hardware platform is a single unit of a much greater and complex system. The UAV is part of an unmanned aerial system (UAS), which is also composed of a control station where the interfacing between the UAV and the controllers are carried out, a communication system that allows for the relay of information between the UAV and the control station and peripheral tools that help maintain the system’s functionality.

Autonomy vs. RC

Older versions of a UAS will have more frequent interfacing between the UAV and the ground control to define flight details like path and altitude; however, many UAVs are now programmed with an extremely high level of artificial intelligence on-board, allowing them to operate completely autonomously. That is, they have on board flight diagnostic software that can detect elements, like wind speed, and adjust to these conditions, meteorological and otherwise. For businesses  routinely dealing with extensive data collection, autonomous drones are crucial to achieving the perfect level of image overlap at the highest  resolution. There are a variety of UAV platforms on the market that are able (keyword) to collect data. The differentiator is finding one that collects data that can be of use! The common misconception is that lots of data means lots of information. The truth is, if you don’t have high quality data going into your GIS mapping software and you don’t have the right algorithms to identify your problems, you won’t obtain anything that can help you make better business decisions (saving time and money).

Hobbyist UAVs, which are often shown privately taking videos across college campuses and over Caribbean beaches, are flown using a remote control that is operated by a human. Thus, much more prone to error, but often more cost effective. The DIY method, while a fun activity, is not the UAV of the future. Nonetheless if you fly under 400 ft and don’t accept money for your photos or video footage, you are free to do it. The UAVs of big business, which I will touch on later, must be autonomous. Let the computer do what it is good at: sense and avoid, data collection etc. and leave the rest, like ground truthing, to humans. (Although I believe that the future will even rid us of these activities. A topic I will save for a future post.)

Remote Sensing

UAVs typically carry a ‘payload’ depending on the needs of the ‘operator’. The payload refers to the sensor that is integrated to the UAV collecting imagery and data. Certain UAVs, like the SenseFly EBee, have a single payload that can take visual imagery with a NIR (near infrared) option for creating maps and elevation models. Other UAVs, like the PrecisionHawk Lancaster, provide a swappable sensor option to fly numerous payloads. The PrecisionHawk platform can carry up to 15 different sensors, depending on need, and are switched in and out like a drill battery. PrecisionHawk calls their sensors ‘smart sensors’. The plug-and-play functionality allows the user to redefine the UAV’s role whenever necessary. The UAV will read the sensor and adjust to fit the mission.

Visual and multispectral sensors are the most widely use to date and have the ability to identify abnormalities or chart progressions from an aerial perspective. In agriculture, the buzz is around the hyperspectral sensor, which is game changing for improving yield. By identifying specific ‘spectral signatures’ farmers can identify diseased plants, contaminants and ripeness conditions that ensure healthier foods and a more profitable and timely crop. Another sensor creating buzz is the Lidar. The Lidar performs short range, high-resolution topographic analysis specifically where vegetation exists. If you’re thinking applications, you can mentally connect this to mapping forest depletions and measuring the amount of biomass left immediately after a harvest.

Classification

Given the great diversity of UAV types, there are a myriad of ways by which they are classified. The most basic categorization is determined by how long and how high the UAV can fly. In this classification, the average high altitude, long endurance UAV is able to fly over 15km on average with an endurance lasting over one day. This is the type of UAV that the military uses, and it usually entails complex software and hardware to support its operations.

The UAVs used for civilian purposes fly shorter flight times, at lower altitudes and slower speeds. Most fixed wing, small UAVs can remain in the air from 45 minutes to an hour at altitudes that can capture imagery as low as 1cm/pixel. This is important for applications such as plant counting in precision agriculture. As soon as bulbs begin to pop up at the start of a grow season, farmers have the ability to fly low and slow over their acreage and collect data quickly enough to replant a specific area if necessary. You can also imagine an application for a search and rescue mission that detects the heat signatures in missing persons after a disaster.

However, the most popular classification for civilian UAVs remains fixed wing and rotary. The fixed wing platform follows the usual airplane design and flies a preprogrammed flight path (think PrecisionHawk and Sensefly). On the other hand, the rotary type, which uses a multi-component propeller system, can move in several directions, think Aeryon Labs and 3D Robotics. Fixed wing UAVs are able to calculate flight plans and capture consistent data across large areas, while rotary UAVs can hover in a single location for some time and be used for thorough inspections.

SenseFly Ebee                                50 min in flight               1.5 cm resolution         Fixed

PrecisionHawk Lancaster           60 min in flight               .08 cm resolution        Fixed

Roboflight RF1                                60 min in flight               1.54 cm resolution      Fixed

Aeryon SkyRanger                        50 min in Flight                                                      Rotary

 

The Place of UAVs in Society

How are drones really going to affect civilian markets?

UAVs in Agriculture

The AUVSI Annual Report predicted that agriculture will cover 80% of applications in the UAV civilian market.  Many people fail to recognize that agriculture is a data hungry and data intensive business. Farmers want to know how to calibrate fertilizer use and maximize yield by identifying the best type of grains to plant. UAVs offer the ability to gather data quickly, more often and in a more cost effective way.

Additional sensors also mean added insight. For example, a drone fitted with an infrared sensor can map the thermal profile of the area, thereby spotting thermal anomalies that can identify sick plants. Currently, multispectral sensors are being used by both farmers and fertilizer companies to measure nitrogen levels in the soil. In doing this, both parties can precisely determine the necessary usage for a certain area, saving both parties lots of time and money.

UAVs in Oil and Gas

Beyond agriculture, the oil and gas industry is looking at drones for exploration, insurance and safety. In many cases, rigs are surveyed visually for damage and deterioration. This entails the risky process of a technician rappelling down to identify key areas in the rig’s structure. With drones, the dangers posed are eliminated and the accuracy of determining the integrity of the structure is substantially improved. The UAV can fly over the areas of interest and use multispectral sensors to spot rusting and deformation. With the ability to fly everyday, companies can easily chart progression (as insurance) in a very cost effective manner.

High-res, visual sensors allow UAVs to survey the immediate geography of a potential oil well and use this information to come up with detailed 3D maps charting the area. This is markedly easier in the case of PrecisionHawk, for example, because the post-processing of the collected visual data is automated and integrated into the entire work cycle. The applications range from mapping oil spills moments after they occur, compared to hours with satellites (if you're lucky), to using a Ground Penetrating Radar (GPR) sensor for tracking, mapping and monitoring underground pipelines. The creation of a methane and/or CO2 emission sensor allows a platform to be flown around plume stacks to monitor emissions, and by using a high resolution, multispectral sensor (or even hyperspectral sensor) drones can determine the composition of the soil and the underlying soil/material properties. This can, obviously, be used to identify areas of interest for potential oil pockets.

UAVs in Emergency Response

The ease and speed by which UAVs can be launched is especially crucial when applying them to emergency response operations. Consider the case of the Oso landslide in Washington. With rain pouring in and the geography drastically changed, rescuers needed a way to gather a huge amount of information to help facilitate the rescue effort. Manned aerial vehicles can do this, but with lesser data quality at higher risks. For one, in the case of the mudslide, flying low was often impossible because of surrounding foliage and bad weather conditions. If you’re dealing with a small area, it is often difficult for manned vehicles to fly from an outside airfield, survey a small space, and then fly out, especially if bad weather is a factor. These problems are eliminated with the use of UAV platforms that can be launched on-site and used often to monitor and collect aerial data.

Visual sensors can collect data that is stitched together to form 3D models of the affected topography to chart any changes in landscape hours or days after a disaster. Thermal sensors can detect heat signatures that differentiate humans and animals from objects that may be invisible from the ground.  The ability to collect aerial data, instantly, will be key in future emergency response scenarios for organizations ranging in size from FEMA to the county sheriff’s office.

Key Issues Surrounding the Future of UAVs

Who is controlling them?

Controversial as it is, the use of UAVs, for civilian purposes, is hounded by many questions. The majority of civilian drone users are not licensed pilots; however, many drone platforms had this concern in mind upon development. To deal with this, the PrecisionHawk Lancaster, for example, has onboard flight diagnostics that allow the bird to adjust flight patterns when needed, such as in the case of overwhelming turbulence or mechanical problems that drastically reduce the potential for failure. Moreover, the interface of the UAV is also made intuitive and easy to follow so that non-pilots will be able to adeptly handle them with ease.

Will it infringe upon my privacy?

The other issue surrounding UAV use, one that is a hot button topic nowadays, is privacy. When UAVs fly, the data and images that they gather may impinge on the privacy of certain individuals. In a speech by Senator Diane Feinstein of California, this concern is verbalized as she noted the need to come up with what she calls as “reasonable rules” on privacy to “protect the American people.” Initially, the FAA had instituted a ban on the use of commercial drones, an extension of their rules on the use of model aircrafts, but the ban was revoked by a federal judge this year. With such a pervasive anxiety on matters of privacy and personal data, the FAA has helped  advance drone technology by starting the discussion on these rules instead of merely silencing them. Fortunately, the agency has promised a clearer set of rules regarding drone use by the end of this year, already providing a roadmap to this point at the start of 2014.

As a member of the UAV community, I can understand both sides of the story when it comes to the widespread acceptance of civilian drone use. However, I have a perspective that not many are privy to. I have the opportunity to hear, everyday, how this technology will truly change our businesses for the better. Essentially, better information means better business decisions and less opportunity for risk.

The applications for unmanned systems are endless. When civilians can see and understand how this will affect the food on their table, the effectiveness of their police departments and the health of their environments, to name a few, I believe that the close to home story will soften public perception and assist with wide spread adoption.