Another very important piece of Italian systems introduced was the DE-1164 integrated sonar system, which is the Italian version of Raytheon AN/SQS-56 sonar.
Other improvements of Type 051G1 over earlier units included using HY-1J AShM to replace HY-1 AShM, with the latter incorporating following improvement: lower cruise altitude achieved with radio altimeter, higher accuracy and better jamming resistance achieved with mono-pulse seeker.