Did US manipulate GPS during Kargil War as shown in ‘Operation Safed Sagar’? Ex-IAF chief explains

What were some of the challenges you faced while carrying out bombing operations at night at such a high altitude?

The mountains would shine in the moonlight at night. But it had its risks, as the clouds could cover the moon at any time, leading to darkness, and one would have to abort and get out of the valley using your Afterburner/Reheat (for additional combustion in an aircraft) if needed. I used to lead at night, so this decision was mine.

The Pakistanis had put a radar atop a hill on their side of the LoC, which was accurately located and fixed by our ELINT (Electronic Intelligence) aircraft. Headquarters Western Air Command had given us a map with the 3D Platter of the radar pick-up marked every 5 degrees since there was no GIS software in those days.

So, before getting picked up by the enemy radar, we used to enter the valley and fly below the crest line (meaning the highest continuous edge of a mountain range, where the terrain drops off on both sides), descending low to 1 km or about 3,000 feet above the target level before weapons release.

We were within the lethal envelope of their shoulder-fired SAMs (Surface-to-Air Missile). On the first night strike mission, they fired a low-level SAM at us, but it fell harmlessly, as it was most probably fired at the sound of the aircraft in our general direction, without a proper lock on.

Low-level night strike missions had their risks, but their results were much better as we were closer to the target when we released our bombs. In fact, we could even tip our wings and see the impact point in the moonlight.

Could you explain the events following the capture of Squadron Leader Ajay Ahuja?

A single pass over the target, like what we did during our recce missions on May 21, does not make one vulnerable to a shoulder-fired missile.

However, Squadron Leader Ahuja, who was on a Battle Damage Assessment mission, was responding to a call from the Leader of the MiG-27 Formation. He was asked to come and replace him to look for Group Captain (then Flt Lt) K Nachiketa (Retd.), who had gone for a strike at the Batalik sector when his aircraft engine flamed out.

Ahuja was orbiting over the area where the wreckage of the other MiG-27 was located. It could easily have been identified, as it must have been a black patch over the white snow. While orbiting around the wreckage area, he was constantly in communication with another helicopter pilot, who had rerouted for the rescue mission.

The continuous orbiting and his exuberance to keep the crash site in contact may have led him to drift down, bringing him within the engagement envelope of the Stinger missile and getting shot down. But he did everything right after getting hit. As decided for such eventualities, he glided down and hit the Indus River, and called out his coordinates before ejecting. But then he was surrounded and captured by Pakistani troops/irregulars. He died of small arms injury, which means that he was killed as a Prisoner of War.

The Netflix series claims that GPS manipulation by the Americans affected the bombing operations initially. What are your thoughts on the matter?

A group of people does believe that there was some deliberate manipulation. Personally, I do not think that is correct.

Firstly, before May 2, 2000, GPS signals had an in-built induced error introduced in the Civilian Coarse/Acquisition (C/A Code) called Selective Availability. This made it accurate to about 100 metres (across the world, not only over India).

Plus, there was some bias (a kind of systematic problem) due to the error between the WGS 84 (World Geodetic System 1984, a standard coordinate system and map reference frame used around the Earth) and the Everest Spheroid (another reference model of the Earth, first defined in 1830 by Sir George Everest, the Surveyor General).

The Indian maps were based on the Everest Spheroid. This had to be corrected for in the handheld GPS sets, which displayed information only in WGS 84 coordinates.

However, the Time Arc-6 GPS sets built into the MiG 21 and MiG 23 BN aircraft allowed one to select to fly on Indian Everest coordinates. As the Army used to give us targets in Mil Grid (Indian Everest Coordinates), we used to physically mark them on a 1:50,000 map and then use our scale to measure the exact coordinates in latitude and longitude.

Then, we had to count every contour to get an exact altitude and then fly at an exact altitude to be 4 km above the target to release our bombs. So, as shown in the series, against a surveyed point on the ground (given in Indian Everest Coordinates), a handheld GPS set would show an error, which had to be corrected. I don’t think the Americans had done it on purpose.