New Delhi, Jun15: The Ministry of Science and Technology on Tuesday said that the imaging of objects in foggy weather conditions may now be clearer as the researchers have found a method that can improve the images captured on such days.
With a technique involves modulating the light source and demodulating them at the observer’s end, the researchers have demonstrated the technique by conducting extensive experiments on foggy winter mornings at Shiv Nadar University, Gautam Buddha Nagar, Uttar Pradesh. They chose ten red LED lights as the source of light. Then, they modulated this source of light by varying the current flowing through the LEDs at a rate of about 15 cycles per second.
“The researchers kept a camera at a distance of 150 metres from the LEDs and the camera captured the image and transmitted it to a desktop computer. Then, computer algorithms used the knowledge of the modulation frequency to extract the characteristics of the source.
This process is called ‘demodulation’. The demodulation of the image had to be done at a rate that was equal to the rate of modulation of the source of light to get a clear image”, the MST said.
The team saw a marked improvement in the image quality using the modulation-demodulation technique. The time the computer takes to execute the process depends on the image’s size. “For a 2160 × 2160 image, the computational time is about 20 milliseconds,” Bapan Debnath, PhD scholar at RRI and a co-author of the study said.
The cost of the technique is low, requiring only a few LEDs and an ordinary desktop computer, which can execute the technique within a second.
The method can improve the landing techniques of aeroplanes by providing the pilot with a good view of beacons on the runway, significantly better than relying only on reflected radio waves as is presently the case. The technique can help reveal obstacles in the path that would otherwise be hidden by fog in rail, sea, and road transportation and would also help spotting lighthouse beacons, the researchers associated with this said.
