The evolution of remote sensing platforms

Drones and robots complement traditional platforms, delivering insights in unique use cases.

Guest column by Mike Fuller

Geographic surveys have changed in the last 150 years. What started with early film cameras strapped to hot air balloons, kites and homing pigeons has advanced — both in terms of sensors and the platforms on which they’re deployed. These innovations — which include drones and robots — are changing the way we can collect data, enabling us to gather greater detail and providing richer insights about the world around us.

These nascent platforms are set to explode in popularity. The global market for remote sensing platforms will more than double in the next four years. It’s projected to reach more than $21 billion by 2022, driven in large part by use of drones, according to an October 2017 report from MarketsandMarkets.

Despite the anticipated growth in drone and robot usage, they will not replace traditional remote sensing platforms such as airplanes, satellites and vehicles. The new technologies bring with them some limitations with regard to the number, size and weight of sensors they can carry, capture rates, area covered and and line-of-site restrictions.

As a result, drones and robots will offer new capabilities that complement the traditional platforms and provide greater geographic detail, as well as the ability to be quickly deployed and constantly monitor areas where humans cannot routinely go.

How far we’ve come

To understand how far geographic information system (GIS) mapping and remote sensing technology has come, it’s important to consider how it started. Inventors in the 1800s relied on early film cameras and somewhat unreliable, imprecise airborne platforms — such as hot air balloons, pigeons and kites — to conduct land surveys and do surveillance.

The introduction of a new kind of “bird” — the airplane — opened up new opportunities in the 1900s, supporting the use of more accurate aerial photography for reconnaissance and mapping.

Satellite technology launched remote sensing into space in the 1970s, supporting the collection of detailed multispectral data that led to improved understanding of minerals, soils, urban growth, agriculture and other geographic features.

Even though the technology has become more sophisticated, GIS professionals still leverage data from many of these historical platforms:

• Manned aircraft – planes and helicopters
• Satellites – high-resolution satellites and cubesats
• Terrestrial – survey vehicles and handheld devices

But — much like the impact of airplanes and satellites — we’re on the precipice of another significant milestone for remote sensing. Marked by use of burgeoning drone and robotic technology, this new technology will complement traditional platforms and deliver more insights than ever before possible.

Rise of drones and robots

Drones and robots are the newest remote sensing platforms catching the eye of the GIS community. Not only are they cool and cutting-edge, they open up a new class of use cases that were previously not possible with traditional aerial survey methods. They offer new opportunities to monitor remote areas, and their form factors and cost enables a higher frequency of data collection compared to aerial survey.

Because of their unique features, users are envisioning how these platforms can be implemented for remote sensing in many fields, such as energy, oil and gas, aviation, forestry, transportation, emergency management, and natural resource preservation and restoration.

When the frequency of data from these platforms is coupled with analytics and cloud infrastructure, it is possible to acquire, analyze and act in ways that were not possible before.

Keep in mind, though, that each technology comes with trade-offs. Users should assess their goals, and weigh these factors, to determine if drones or robots will deliver the results they wish to achieve. Let’s take a closer look:

Drones

Drones are capable of delivering ultra-high-resolution data, with ground sample distances (GSD) of 1 cm and accuracy of under 5 cm. However, accuracy is highly variable; it can vary based on the drone model, terrain and software used to process the collected data.

The form factor of many drones also limits the ability to do multi-sensor flights. A drone typically can cover no more than a few square miles per day with a visible or multispectral camera, compared to manned aircraft that span hundred of thousands of acres a day carrying hyperspectral, lidar and orthophotography devices simultaneously.

Because they can be deployed quickly, and on a daily basis, drones offer a cost-effective, practical approach for covering small areas compared to other aerial survey methods. But drone usage currently faces a significant impediment.

Current regulations require operators to maintain sight of the devices during all flights. These line-of-site restrictions limit the distance a drone can go on each flight, and require operators to change locations multiple times for a single survey. As a result, frequent revisits can be labor intensive.

Battery life also plays a role in the usability of drones. Most commercial drones can fly for only about 45 minutes, despite continued improvements in battery technology. Combined with the line-of-site restrictions, battery life impacts the amount of territory drones can cover. Most can handle only a few square or linear miles during each flight, making helicopters or airplanes better suited for projects that span hundred of miles or more.

Despite some of the drawbacks, drones are proving ideal in many use cases — from damage assessment and power restoration after hurricanes to data collection for hydraulic modeling, stream restoration design and aquatic habitat assessment.

For example, drones equipped with bathymetric and terrestrial laser scanning sensors are ideal for supporting riverine mapping applications. In these cases, drones offer an effective alternative when the waterway cannot be accessed, or it is too dangerous to use ground- or water-based survey methods for collecting channel geometry.

Robots

Robotic platforms are flexible, enabling users to attach a variety of sensors, including thermal cameras, lidar and sniffers for natural gas or other hazardous material. They are rarely hampered by payload restrictions, like drones.

And, with programming, robots can return to their chargers when their batteries dip below a certain threshold.

Like drones, there are many potential applications for terrestrial remote sensing robots. One use is for precision agriculture to test soil, water and plant health.

Many utilities are expressing serious interest, too, for robots. These robots can include onboard spectral, thermal and lidar sensors, precision navigation and hazard cameras to perform fine-scale spatial mapping and can acquire a wide array of data from electrical substations.

In this scenario, the robotic platform could detect physical and spectral changes, identify objects, monitor corrosion, detect liquid and gas leaks, and conduct thermal monitoring. Using this model, utilities could track substation environments remotely, saving time associated with physical inspections and enabling earlier detection of potential problems.

Systemwide approach required

Traditional remote sensing platforms — airplanes, satellites and vehicles — will continue to play an important role in GIS mapping. Drones and robots give us new tools that will have a dramatic impact on the amount of detailed geographic information collected.

For these new platforms to be used effectively as complements to traditional platforms, the industry must adopt a systems approach that takes into consideration a number of factors:

• The end application
• The sensors and acquisition protocol that will collect data at the precision required by the end application
• The actionable analytics that need to be extracted from the data
• How the data and insights integrate with the business processes used for decision making.

By taking this approach, those who work in a variety of fields can gather the insights they need to do their jobs more effectively and efficiently, while leveraging the unique strengths offered by these emerging platforms.