US army soldiers look at anti-missile system David's Sling during joint Israeli-US military training at the Hatzor Airforce Base in Israel on March 8, 2018. Photo: AFP/Jack Guez

Israel has carried out a test of its air defenses, which for the first time reveals a highly integrated system that can knock out a broad spectrum of targets, from maneuvering ballistic missiles to simple drones. 

This accomplishment has far-reaching implications, not only for Israel’s defense capabilities but for the United States. The US Army is in the process of developing an integrated tactical defense system called the Integrated Air and Missile Defense Battle Command System.

If the Israeli air defense integration is complete, it is probably the first time that systems optimized for different threats can share threat data and hand off responsibility to different “tiers” of the defense system.

Unlike the US effort, Israel’s integrated system is national and includes ballistic missile defenses (BMD). The US Army system is tactical and only attempts to deal with tactical ballistic missile threats – and even there relies on the evolved but still antiquated Patriot system. 

Above all, the Israeli test for the first time demonstrated a system that can destroy cruise missiles.

While most of the global focus since the Nagorno-Karabakh conflict has been on drones as an emerging unconventional threat to traditional military operations, the cruise missile presents the biggest threat to critical infrastructure installations and defense bases, both forward operating and fixed bases at the national level. 

The rise of high precision cruise missiles in the hands of second-tier actors such as Iran – and Iran’s client Yemen – presents a threat to Israel and to its new-found allies and friends in the Gulf states. 

The unacknowledged Iranian attacks on two Saudi Arabian facilities, Abqaiq and Khurais, made clear that Iran had the ability to fire autonomous drones and cruise missiles and strike targets at high accuracy without a “man in the loop.”

Military vehicles carrying YJ-18 anti-ship and land-attack cruise missiles drive past Tiananmen Square during the military parade to celebrate the 70th anniversary of the founding of the People’s Republic of China. Photo: AFP/Anna Ratkoglo/Sputnik

Cruise missiles on long flights use highly accurate gyroscopes for navigation, augmented by GPS and supported by scene matching cameras and software. Typically gyroscopes are mechanical and electrical, require spin-up time and need to be updated. 

In the past 20 years, ring laser gyros have become available, first in the United States. These gyros are far more accurate than mechanical ones. China, for example, is producing ring laser gyros (RLG), fiber optic gyros and microfabricated MEMS gyros.

These gyros are expensive and range in price from US$2,000 to $100,000 each. But even electro-mechanical gyros accuracy can be updated by GPS, which seems to be what the Iranians did in their attacks on the Saudi oil installations. 

The gyros found there on both drones and cruise missiles were types V-9 and V-10 respectively, either imported to Iran from China or possibly, but less likely, locally manufactured in Iran.  

The major problem for air defense operators has been detection at range for low flying cruise missiles and drones. Radars can easily detect small objects – radar guns are used to measure baseball speed – but they are range limited because of the prevalence of ground clutter that shrouds the incoming object. 

And because a radar could easily confuse a friendly object with one that is a threat, modern air defense systems need to be able to classify objects and identify them as threats. In the case of an integrated system, that classification capability also implies that the appropriate segment of the air defense system will be assigned to respond to the threat.

We don’t know much about what improvements the Israelis have made in their air defenses to account for cruise missiles and drones. But we can speculate that the improvements are largely in radar image processing and in discernment algorithms.

The two main systems in Israel’s arsenal to deal with these kinds of threats are called Iron Dome – Kippat Barzel in Hebrew – and David’s Sling – Sharvit Haksamim, or the Magic Wand, in Hebrew.

A battery of Israel’s Iron Dome defense system, designed to intercept and destroy incoming short-range rockets and artillery shells, in Mount Hermon in the Israeli-annexed Golan Heights on January 21, 2019. Photo: AFP/Jalaa Marey

Iron Dome has been remarkably successful against small rockets, especially those fired from Gaza. The system can also knock out mortar rounds. Iron Dome accounts for 1,500 to 2,000 kills on rockets fired from Gaza into Israeli territory.

One of Iron Dome’s unique features is that it selects only those threats that are likely to cause harm, letting rockets that won’t hit villages or infrastructure to fall to the ground. This saves interceptor rockets for meaningful kills, saves money and optimizes the chance to deal with “swarming” type attacks, like what hit Saudi Arabia’s oil fields. 

The limitation of the Iron Dome system is its coverage area. Each Iron Dome battery can cover about 150km of territory.

David’s Sling is a much heavier air defense system that is replacing the US Patriot and Hawk air defense systems. It is optimized to cover incoming threats at distances of between 40km to 300km. 

David’s Sling is a joint development of Rafael Advanced Defense Systems in Israel and Raytheon in the United States. The system uses an Israeli radar made by Elta, EL/M-2084, an active electronically scanned array multi-mode radar. The radar linked to the air defense system is capable of selecting real targets from decoys. 

It was designed to deal with Russian Iskander missiles and Chinese DF-15 short-range ballistic missiles that have maneuvering re-entry vehicles. The system can also deal with a variety of other Russian, Chinese and North Korean missiles – and respective Iranian knock-offs – such as the Tochka, which is in large numbers in Syria and Yemen.

The top tier of Israel’s air defense system is Arrow 2 and Arrow 3. Arrow 3 is an exoatmospheric capable system that can even knock out enemy satellites.

What became clear in the attacks on Saudi Arabia and in the Nagorno-Karabakh war was that radars were ineffective in detecting even large drones like Turkey’s Bayraktar.

A handout picture released by Israel on December 10, 2015, shows the launch of an Israeli Arrow 3 missile at an undisclosed location in southern Tel Aviv. Photo: AFP/Israeli Defense Ministry

While some of this can be attributed to difficult terrain, it also indicates that both Russian and Western radars were ineffective against relatively slow-flying threats coming in at a low altitude.

It is likely these systems do not have sophisticated computers to sort out real radar returns from ground clutter and they may also lack threat libraries that anticipate undocumented cruise missiles and drones.  

Cruise missiles in their terminal flight envelope may fly as low as 15 meters above the ground.

The successful Israeli test and demonstration takes up an issue of contention between the US Army and Israel over Israel’s ability to knock out cruise missiles. When the US Army bought two Iron Dome systems from Israel, which the US Congress mandated, Israel claimed the system could deal with a range of threats including cruise missiles and drones. 

Until now, Israel could not prove in any conclusive manner they were able to counter a cruise missile attack. It is likely Israel was also in the process of improving and optimizing Iron Dome and David’s Sling against advanced drone and cruise missile threats. 

Israel’s military has been aggressively taking out Iranian supplied rockets and cruise missiles shipped into Syria, Lebanon and Iraq and, no doubt, Israel anticipates that even with these efforts the threat to Israeli territory is real and growing.

With these tests showing Israel’s Iron Dome can kill drones and cruise missiles, one of the key US Army arguments about Iron Dome’s “limitations” is in the process of being erased. 

The other argument, about the availability of source code – which Israel allegedly resists providing – relates more to the algorithms Israel’s Defense Forces have developed to assure these new types of threats can be countered rather than hardware advances. How to bridge this gap with the US remains an issue still on the table. 

Source code is the computer instruction set of commands that operates the air defense system. 

For Israel, these algorithms in the source code represent high-level secrets that go beyond industrial security and are critical to the national security of the country. How this gap can be bridged is a challenge for both sides, but it is clear that a creative effort would help the US Army field a competent system.