Delhi has been covered with fog lately, making visibility extremely low, so much so that even traffic comes to a halt amid the harsh winter conditions, but have you ever wondered how do planes manage to make a safe landing even when the visibility is next to negligible?

Dr. Shubha V Iyengar (Photo: @@BJP4India/ X)
Surprisingly, this is no magic, it was made possible by the decades of relentless hard work put in by an unsung hero - Dr. Shubha V Iyengar, who also won a
Padma Shri award for her unique contribution to aerospace technology.
Dr. Shubha’s ‘drishti’ that helps thousands of planes land safely
Drishti, India's first homegrown runway visibility system, was Dr. Shubha's crowning achievement. Partnering with the Indian Meteorological Department, she created a device measuring down to four meters.
Before Drishti, Indian airports bought expensive runway visibility measuring instruments from Finland and Australia, plagued by maintenance woes. Her version came at one-third the cost instead, with local parts for quick fixes. Deployed by 2014 in Delhi, Kolkata, and Lucknow, it proved to be a life-saving device even during Delhi's brutal fog seasons, saving flights and lives.
Who is Dr. Shubha V Iyengar?
Dr. Shubha V Iyengar, 71, is a former distinguished scientist from CSIR-National Aerospace Laboratories (NAL) in Bengaluru. The youngest of nine siblings, she topped her BSc and MSc at Central College, then earned a PhD.
Her father pushed her into science when few women ventured there. Joining National Aerospace Laboratories or NAL in 1974, she dedicated over 40 years to aviation technology, retiring but still advising. Her Padma Shri honours a life of quiet service to India's skies.
Her career in aerospace innovation
At NAL, Dr. Shubha tackled aviation's toughest issues, like fog, smog, rain blocking runway views during critical takeoffs and landings. She led teams across science and engineering projects, focusing on self-reliance.
Her work bridged labs and real-world airports, reducing foreign dependence. Even post-retirement, her expertise guides institutions.
Why is ‘Drishti’ important?
Drishti is like the runway's eyes during fog, rain, or dust storms. It constantly measures how far pilots can actually see down the runway, anywhere from 25 meters in thick fog to over 2,000 meters on clear days. Using a light beam between two points, it gives air traffic control real-time numbers so they know exactly how safe it is for planes to land or take off.
According to an India Today report, designed for India's wild weather, Drishti catches sudden visibility drops at dawn/dusk when accidents spike. Delhi airport alone runs 10 units across its runways, replacing pricey imports with affordable, locally fixable tech that keeps flights moving safely.
It is budget-friendly
Cost efficiency let more airports to afford top tech, cutting dependency on foreign vendors. Dr. Shubha's system handles extreme weather reliably, making Indian aviation more resilient