Over 900 rockets have been launched at Israel during the past month. Almost all of them have spotted by the Israeli Air Force, and resulted in an alarm sounding sending Israel’s residents running for cover. Lt. Col Lefi Itach described the process in a Times of Israel article. He describes the complex process.
a Grad rocket with a 40-kilometer range. His soldiers, seated beside air force personnel in a joint command center in central Israel, receive notice of a launch after five seconds. By then they have verified that the object is neither a flock of birds nor a crop-duster tracing the ballistic path of a rocket.
Then the air force’s electro-optic systems analyze the heat signature of the rocket and the trajectory of the take-off and provide, based on the projected kill capacity of the projectile, the Home Front Command with an initial target area.
Five seconds later, additional radars, tracking the behavior of the projectile, narrow the target area significantly.
Itach added that there is a long history of early warning among the Israelites, quoting Ezekiel 33 — “when he seeth the sword come upon the land, he blow the trumpet, and warn the people.”