TAIPEI -- Taiwan will soon test two sets of mobile passive radar systems in the field in order to detect the increasing fleet of Chinese stealth fighter jets, announced a Ministry of National Defence official on Monday (May 15), reported Liberty Times. 

Two sets of mobile passive radar systems are going to be deployed for field testing at some point this year said the official. The mobile radar units, which were engineered by National Chung-Shan Institute of Science and Technology (NCSIST), are slated to being full-scale production in 2020. 

In order to counter the Chinese People’s Liberation Army Air Force (PLAAF) increasing use of J-20 and Sukhoi Su-35 stealth fighters, Taiwan's military is planning to use a combination both active and passive radar systems. Taiwan's upgraded F-16Vs would handle active radar detection of China's stealth warplanes, while the new mobile units would handle passive radar detection of incoming stealth jets. 

According to the NCSIST's website, the new radar system makes use of multi-angle target detection to enhance the early warning capabilities of Taiwan's defenses. As the mobile units would be linked remotely to active phased array radar systems, they would be able to "amplify" the cross sectional area of unidentified aircraft and lock-on to them. 

In addition, because the systems do not emit radiative signals, they are less vulnerable to electronic jamming and anti-radiation missile attacks. 

On May 9, China announced it had held sea training missions of its J-20 fighter jets for the first time. The J-20 is China's answer to fifth-generation stealth jets such as the U.S. F-22 and F-35.

Two days later on May 11, Chinese Su-35 jets and Xian H-6K strategic bombers for the first time flew over the Bashi Channel separating Taiwan from the Philippines, the Chinese Air Force said.