for the USN, these were initially the 4 burkes deployed to Rota Spain as part of the EPAA for european bmd... the reason they required SeaRAM and not just RAM is because the version of the aegis bmd system these ships used (ie. BMD 3.6.x/4.x) could not operate in integrated air and missile defense (IAMD) mode hence when they were performing their bmd picket duty their spy1 sets could not perform aaw defense... modernized burkes (ACB-12) and new build IIA burkes (ACB-16) would have aegis baseline 9.C with BMD 5.0 CU/5.1 which is capable of operating in IAMD mode hence their spy1 can perform bmd and aaw modes simultaneously...KWAM wrote:... and some Arleigh Burke class ships in the USN use the SeaRAM instead of the Mk 48 even though they have the Aegis system.
in you ships case, because you are showing use of SM-3 block IIA, this means you are using aegis BMD 5.1 which means your spy1 set can function in IAMD mode as well...
which gives you a (USN) RL technical basis to follow @citizen's suggestion on RAM
(I believe you also have an ESM system which will provide the initial seed target frequency for the RAM for it to use if it is launched in dual-mode, ie. rf seeking midcourse, passive IR terminal -- so combined: spy1 in IAMD mode provides the radar track while your ESM provides the rf freq track for your RAM in dual-mode, while if RAM is launched in autonomous-IR/AIR mode it will just use spy1 for the radar track)...