The Air Force are also on guard ahead of G20 Summit in Delhi making the city's airspace as impregnable as possible with fighter jets, surface-to-air missile systems, anti-drone systems, airborne early-warning and control systems (AEW&C) and other sensors being deployed on September 9-10.

"The IAF's ODC (operations direction centre), which will liaise with the JCAC (joint control and analysis centre) and other agencies involved, will have the composite air picture at one place to detect threats, ranging from small, slow-moving objects like drones to large, fast- moving aircraft," a source said.

"If a threat is conclusively established, the ODC will decide what is the best method, or which particular weapon system should be used, neutralize it," he added.

Similar Air defence arrangements are made to tackle aerial threats from hostile situations during events like Republic Day and Independence Day and other important occasions every year.

But the scale of preparation for G20 is much larger.

Frontline fighters like the Rafales, Mirage- 2000s and Sukhoi-30MKIs will patrol the skies, even as air-bases in the region like Ambala, Bareilly, Sirsa, Bhatinda, Gwalior and others will also maintain ORPS (operational readiness platforms) round-the-clock.

This involves two to three fighters being kept combat-ready in blast pens adjoining the runway at an airbase for immediate take-off whenever an alarm is sounded.

Similarly, a wide array of surface-to-air guided weapon systems have been deployed to protect the Delhi-NCR. These include MR-SAMS (medium-range surface-to-air missile systems), jointly developed with Israel, which are designed to destroy hostile aircraft, helicopters, cruise missiles and drones at a range of 70-km.

Source: TimesofIndia