The method is relatively old, but it works well: an extensive radar system is mounted on a platform that resembles an airship, making it efficient but cheap to operate. The system, known as the High Availability Aerostat System (HAAS), has not been given too many specifications, but it is a very large device. The device, operated by the Israeli Air Force, is said to be one of the largest of its kind. The High Availability Aerostat System (HAAS) is very simple: the unmanned Sky Dew is tethered to the ground and has a radar system that can detect any threat in the airspace, whether it’s a drone, missile or drone. It can also, of course, detect enemy fighters.
The system is being developed by the Israeli Ministry of Defence with the help of two companies: Israel Aerospace Industries, an Israeli state-owned company, and TCOM, an American manufacturer, which developed Sky Dew. The system will be operated by the Israel Air Force (IAF). The system will complement the existing Israeli ground-based radar systems by providing high-altitude surveillance – thus strengthening the Iron Dome.
The HAAS system has the advantage of being able to stay aloft for extended periods of time (up to 20 days for similar systems) in a wide range of weather conditions, and will require minimal maintenance once fully operational – all of which makes it a cost-effective aerial surveillance system. According to The Aviationist, the system has passed its final test and will soon be deployed in the north of the country at a location that is, of course, unnamed.
According to Boaz Levy, CEO of Israel Aerospace Industries, which is involved in the development, the sensor system deployed aloft will provide a significant technological and operational advantage in the accurate and early detection of threats.
Similar spy balloons, which have been in operation since the beginning of the century, detect incoming threats that are invisible to conventional ground-based radars because they fly too low. The advantage of these systems is first and foremost their cost-effectiveness, as mentioned above: they do not need to be manned, they do not need to be touched for days on end and they do not require fuel to fly, unlike spy planes and other more conventional devices.
In Afghanistan and Iraq, for example, the PTDS (Persistent Threat Detection System), developed by Lockheed Martin for the US military, began operating in 2003. But the TARS (Tethered Aerostat Radar System), located on the US-Mexico border, consists of larger balloons.