Unmanned aerial remote sensing: Sky is the limit

Remote sensing has been around for more than a century. In the 1960s, space borne satellite imaging platform unveiled a new dimension to the application of remote sensing that served civilian purposes. Images sent by satellites offered valuable information about diverse issues starting from weather condition to deforestation to river erosion. Despite usefulness, low resolution and large time gaps of getting images of designated areas were among the major limiting factors. Although manned aerial vehicle-based imaging platform addressed these issues, due to the necessity of expensive aircraft and the airstrip to take off, it fell short of being an on-demand low-cost solution to fully exploit the potential of remote sensing. The recent emergence of unmanned aerial vehicles, often costing less than US $1000, appears to be the last leg of remote sensing solution. Research suggests that the global service market alone of unmanned aerial vehicles (UAVs) based remote sensing could reach above $100 billion in the foreseeable future. And the economic benefit out of the utilisation of images captured by UAVs could be far more than the likely service revenue.

UAVs are commonly known as drones. Often we encounter them in the toy stores. It's fun to attach cameras with them and enjoy watching aerial photographs while controlling their flying with radio control. Often these flying toy devices create nuisance in the air space. They could also be used for conducting unlawful activities. Such likely usages lead to negative perception about UAVs in civilian hands, consequently leading to stringent regulatory measures. But low-cost UAVs that require no airstrip to take off and land, could open a new dimension of remote sensing. 

Although UAVs look like toys, they have a long history, with their roots in the military. The first recorded flight of UAVs appears to have been during World War One. Till 2000, the usage of UAVs was limited within the sphere of the military, for espionage purposes and even dropping ammunitions. In 2005, post-Katrina damage assessment in the USA demonstrated the potential of UAVs in civilian applications. The dawn of the 21st century has been witnessing a flurry of UAV activities starting from vehicle development to software and service innovation. The projected commercial drone hardware revenue worldwide is expected to jump from just above $500 million to over $12 billion by 2025-a 24-fold increase over a span of 10 years. Being a member in the technology stack driving the fourth industrial revolution, UAV-based remote sensing is about to transform many jobs and industries across the world.

Modern UAVs could be fitted with diverse, but powerful sensors--starting from a low-cost video camera to LIDAR to multi-spectral as well as infra-red image sensors. UAVs fitted with 50MP to 100 MP metric aerial cameras, smart triggering of the camera by waypoints, mission planning applications, geo-tagging of all images' locations, remote controllers (drone and camera), long life lithium-ion battery, and industrial-grade build of the camera and aerial lenses are turning them into powerful aerial remote sensing platforms. In a single mission, flying over an hour or so, a UAV can capture photographs at a predetermined time interval, and create a seamless image compiled of the collage of pictures covering several square kilometres. These images can be fed to data analytic exercise to derive actionable insights, starting from elevation and volume calculations of a construction site to chlorophyll map of croplands.

Some of the notable areas for applications of UAV-based remote sensing are surveying, precision agriculture, terrain mapping and modeling, river erosion assessment, power line and gas pipeline monitoring, road repairing cost estimation, and building construction.  It has been reported that high-resolution images captured by UAVs can result in horizontal accuracy up to 10mm and vertical accuracy of 25mm. UAVs have been found to be immensely useful in surveys. It's being reported that UAV-based remote sensing could offer a quantum leap to surveying, after the past five quantum leaps over last 50 years driven by technologies such as the electronic distance meter, GPS, mobile robotics and laser scanner.

Opportunities are unfolding for using UAVs across the whole value chain of infrastructure management, starting from project planning & design, to earthworks management to model verification during construction. Several infrastructure industries can benefit from drone technology more quickly than others. Energy sector, roads, railways, telecom and oil & gas industries operate extensive networks of complex assets, distributed over vast areas. UAV-based remote sensing and data analytics applications can play a vital role in investment monitoring, maintenance, and asset inventory.

Similarly, diverse meaningful maps such as soil ingredients, chlorophyll contents of leaf, and pest attacks can be produced from images of croplands captured by UAV-borne sensors. These maps can not only be used for assessment, estimation, and planning, but most importantly they can be directly used to control the discharge of fertiliser and pesticides by machines in a very precise manner. As a result, fertiliser and pesticide usages could be optimised, often minimised too. Such potential of UAV application in agriculture will likely increase yield as high as 15 to 25 per cent without increasing the need for inputs.

As UAV images can be sent anywhere in the world over the internet instantly, the UAV-based remote sensing for civilian applications starting from infrastructure management to precision agriculture is also opening high-end data analytic service outsourcing market. It's being reported that UAV analytics market is projected to grow from $ 1.57 billion in 2017 to $ 5.41 billion by 2022, at a compound annual growth rate (CAGR) of 28.11 per cent from 2017 to 2022. The increasing demand for sophisticated industry-specific analytical solutions that can help companies obtain actionable insights from the data captured by drones is expected to fuel the drone analytics market.

To benefit from the unfolding opportunities of UAV-based remote sensing, both for local usages and data analytic service export, developing countries like Bangladesh should attempt to be lead users as opposed to being a follower. Instead of just focusing on regulation, they should aggressively invest in research and development (R&D). In order to create the local market of UAV data analytic services, the policy of using UAV-based remote sensing should be adopted by major government departments. Strengthening internal capacity for consuming such services should be given due attention. UAV-based remote sensing can fuel innovation in diverse local economic sectors, and most importantly, create and demonstrate the capacity of delivering high-quality data analytic service to the global market-opening the opportunity of creating high paying jobs for knowledge workers.

M Rokonuzzaman Ph.D is academic and researcher on technology, innovation and policy. [email protected]