The Navy has not been able to successfully demonstrate the reliability of its suite of integrated systems to defend against anti-ship cruise missiles and other threats, according to a report by the Pentagon’s top weapons tester.

The report released earlier this month by the Office of the Director, Operational Test & Evaluation (DOT&E), said the integrated sensor and weapons systems represent an improvement over their non-integrated counterparts, but still had a ways to go to show capability.

“The ability to effectively complete the self-defense mission against the types of threats for which the overall systems was designed has not been successfully demonstrated,” said the Jan. 9 report. “In addition, reliability problems further degrade the ships’ ability to complete this mission.”

The section of the report focused on four key Raytheon [RTN]-built systems: The Ship Self- Defense System (SSDS); Cooperative Engagement Capability (CEC); the Rolling Airframe Missile (RAM); and Evolved SeaSparrow Missile (EESM).

“The Navy must complete the currently planned operational test program and conduct additional testing to demonstrate the correction of significant deficiencies with SSDS Mark 2, RAM, ESSM, CEC and legacy ship self-defense combat systems,” said the DOT&E report that covers fiscal 2011, which ended Sept. 30.

In addressing the findings, Naval Sea Systems Command (NAVSEA) said SSDS Mark 2 in more recent testing has continuously corrected deficiencies, improved capabilities based on evolving threats and provides "a capable, sustainable and maintainable combat system for Navy aircraft carriers and large deck amphibious ships on deployment overseas." ESSM, RAM and CEC have also shown improvement, NAVSEA said.

"In 2011, significant improvements were made and the latest SSDS detect-control-engage capability was recently demonstrated during operational tests in November to December 2011," the command said. "These events are currently being analyzed and several additional operational tests are planned for the Fall of 2012."

SSDS is the combat system on ships that networks an array of weapons and sensors to provide detect, track and engage sequences. It utilizes CEC, which fuses data from multiple sensors into a single, real time composite tracking picture. RAM is a short-range missile designed to counter anti-ship cruise missiles, while ESSM is a medium-range weapon to fend off air and surface threats.

Among other ships, the systems are deployed on aircraft carriers and Marine Corps amphibious ships, and newer versions are set for use on vessels currently in the acquisition stages.

The report cited an earlier DOT&E assessment submitted to Congress in March that found the combat systems on the LPD-17 San Antonio-class landing transport dock ships and CVN-68 Nimitz-class carriers continued to “have difficulty” in defeating certain types of anti-ship cruise missiles. That report covered testing that took place from January 2008 to March 2010.