A successful demonstration of the Armscor-sourced hostile fire indicator (HOSFIN) capability is rated as one of the 2018/19 financial year’s highlights by the State-owned defence and security acquisition agency.
Its latest annual report lists HOSFIN as one of the major technology programmes it is involved with and working on.
Introducing the need for a HOSFIN capability, the report notes South African Air Force (SAAF) helicopters operating at low altitudes in combat conditions are vulnerable to ground fire from ground weapons ranging from sniper rifles, rocket-propelled grenades to anti-aircraft artillery.
“The SAAF currently has no sensors capable of detecting small arms fire. Rooivalk and Oryx helicopters have been hit by small arms in the Democratic Republic of Congo (DRC) theatre operations.”
This saw a decision taken to investigate HOSFIN based on the Reutech RSR 150 sensor adaption to provide a radar-based HOSFIN capability.
“Most HOSFIN sensors rely on the sound of the passing bullet to signal continuous tracking and classification of the incoming round to the pilot instead of relying on single event detection via acoustics. This significantly lowers the false alarm rate.
“The highlight of the past year was the successful demonstration of the radar based HOSFIN capability at the SAAF Test Flight and Development Centre in November 2018.”
The report does not give any indication of development cost and does not supply details on manufacture and fitment to the SAAF helicopter fleet, particularly those earmarked for continental deployment on peace support missions.
According to Reutech Radar Systems, the RSR 150 3D radar sensor was developed specifically for vehicle self-protection. “The radar sensor is optimised for the rapid acquisition and tracking of multiple incoming projectiles, such as Rocket Propelled Grenades, in order to designate fast reaction soft or hard kill countermeasures. The radar is also capable of being used to detect and track bullets in tracking sniper fire and location of hostile fire,” Reutech said.
The sensor uses X-band antennas and special signal processing software to detect threats.