Spy satellites, advanced reconnaissance aircraft and unmanned aerial vehicles are just some of the systems that Israel is using to track events in Syria and specifically to keep an eye on the country’s chemical weapons arsenal.In recent weeks, Israeli politicians and military officers have repeated the mantra that Israel is carefully tracking Syria’s chemical weapons and has warned that if it sees a Hezbollah attempt to get its hands on the weapons, it will use force to stop it.On Tuesday, IDF Chief of Staff Lt.-Gen. Benny Gantz said that forces loyal to President Bashar Assad were still in control of the chemical weapons and that security around the facilities had recently been boosted.But how does Israel know this, and how is it tracking Syria’s chemical arsenal? Israel regularly keeps an eye on Syria, but has increased its surveillance and reconnaissance in recent weeks due to fears that as Assad falls, Hezbollah or another terrorist group will try to get its hands on the massive stockpile. Syria is believed to have one of the largest chemical weapons arsenals in the world, including mustard gas, VX and Sarin.First of all, Israel can use its satellites and currently has five operational in space, including Ofek-9, TecSar, Ofek-7 and Ofek- 5. The IDF also receives services from the commercially-owned Eros-B1.The Ofek satellites are reported to have a camera that enables them to see targets the size of half-a-meter, but the real advantage is TecSar, which is one of a handful of satellites in the world that use advanced radar technology instead of a camera.This enables TecSar to create high-resolution images of objects on the ground in any weather conditions, as well as at night, and to see through certain rooftops that are not made of concrete.When Israel launched the Ofek-9 in 2010, senior defense officials explained that the presence of five satellites in space provided the country with the ability to keep “eyes” continuously on a target of interest.The second capability available to the IDF is the use of reconnaissance aircraft like the Beechcraft Kingair B200 twin Turboprops that the IAF’s Squadron 100 flies.The aircraft use an advanced and long-range electro-optical camera that enables operators to search and track land and sea targets, day or night and in all weather conditions.Developed by Elbit Systems subsidiary El-Op, the camera is said to be one of the most advanced of its kind in the world. While the exact specifications of its resolution are classified, it has amazing resolution, enabling operators to track targets even from standoff positions of dozens of kilometers.This would mean that Israel could potentially use these planes to gather intelligence on Syria while still flying in the Golan Heights or while flying over the Mediterranean Sea.Israel also has a large array of UAVs at its disposal for intelligence, surveillance and reconnaissance missions. While Israel is known to fly its UAVs often over Lebanon and the Gaza Strip, it has never revealed that it does the same over Syria, although foreign reports have claimed that the drones often fly over Iran.UAVs have an advantage in flying over countries like Syria that have impressive and condensed air defense systems, since the drones usually have a relatively low radar signature and have the ability to fly at high altitudes, out of range of surface-to-air missile systems.The two drones suited to such a mission are the Heron TP, Israel’s largest UAV, and the Heron 1. The Heron TP has a 26-meter wingspan – the same as a Boeing 737 – and can reportedly stay airborne for over 24 hours. The Heron 1 is a smaller version but is also capable of long-range missions and can stay in the air for over 24 hours.Israel is likely working closely with the United States – which has more reconnaissance satellites and is also said to be tracking movements at Syria’s chemical weapons facilities.Human intelligence – in the form of spies on the ground in Syria – is also available to the West to help create a picture of what is happening at the facilities.This is most probably being done with the assistance of officers who have defected from the Syrian military, as well as with the rebels themselves.