Prof. Arup Dasgupta
Unmanned Aerial Vehicles or UAVs, also known as drones, conjure up pictures of a mean war machine, controlled from far away, raining death and destruction on the enemy. Like most military technologies, UAVs have found their way into civilian use from crop dusting to aerial photography and thereby hangs a tale.
Remote sensing is always associated with satellites. However, historically, remote sensing started with military aerial surveillance, initially through black and white photography, which was overtaken by colour IR camouflage detection film. These technologies were adopted for civilian survey and mapping. The arrival of the Charge Coupled Devices or CCDs brought in a major disruption in remote sensing. Initially, CCDs were used on satellites because they were low powered, did not require any mechanical scanners, and provided digital data which maintained its integrity over time and generations of reproductions. However, CCDs had one major problem: The size of the CCDs restricted the swath which did not create any problem for satellites but restricted their usage on aircraft. Advances in CCD technology resulted in both the increase of the size of linear arrays and the fabrication of area arrays.
With these developments, people were ready to write the epitaph for aerial surveys. But just as CCDs replaced cumbersome mechanical scanners on satellites, they also replaced aerial photographic cameras with high-resolution digital cameras which were more versatile because a single camera could house both panchromatic and multispectral sensors. Aerial surveys, therefore, took on a new life. Today, while satellites promise high resolution up to 25 cm, aerial cameras provide centimeter-level resolution for high precision tasks. Aerial surveys have one big advantage over satellite remote sensing; they provide data acquisition as and when needed. The disadvantage is that aerial surveys have to be approved by the local aviation and, in some cases, security regulators.
This is where the UAVs score; they are cost effective and hopefully should not require elaborate clearances. However, like all disruptive technologies, civilian use is beset with regulatory issues and regulators will always first deny permission to be on the safe side, particularly if the technology comes from the military stables. It is interesting to note that model radio control aircraft enthusiasts have already broken ground by mounting cheap digital cameras on their models. In India, wedding videographers make a neat pile using a video camera on a quadcopter to provide a novel record of the wedding procession. While such recreational uses are limited by duration of flight and line of sight control, UAVs will use longer duration flights, possibly under autonomous control or remote vision remote control.
Recognising these issues, national regulatory authorities need to apply their minds to evolving a set of rules that will allow the use of UAVs without jeopardising security, causing danger to life and limb and interfering with other aerial vehicles. Just saying ‘no’ is not an acceptable solution.