Any idea what 's in that semicircular radome forward of the mast? Some indication by a poster that it could be Next Generation Surface Search Radar (AN/SPS-73(V)18). Thoughts?
I would like to re-vist this.
One thing I am puzzling over is the apparent absence of any dedicated fire-control radar for the BAE Mk-45 5"/62 gun on the River-class.
The
Congressional record that mentions Canada procuring the BAE Mk45 itemizes four (4) Next Generation Surface Search Radars, described only in generic terms as the U.S. Navy's multi-mission navigation, which is a surface search and periscope detection radar replacing multiple legacy surface radar systems — no AN/SPS designation given. I note though NGSSR is often associated in U.S. Navy documentation with the AN/SPS-73(V)18 program, although the Congressional notification does not actually identify a specific AN/SPS designation.
Unlike later-Flight-III Burkes, which are getting AN/SPQ-9B as a purpose-built track-while-scan (TWS) radar feeding the Mk 160 GCS for anti-ship-missile-defense gunnery, nothing in the public River-class documentation points to an SPQ-9B-class system. So is the Mk-45 BAE gun for the River Class not getting a dedicated FC radar?
The public sketches suggest that.
One possibility is in the past with the Mk 34 GWS baseline on the USN Arleigh Burke class it may have been shown that the older SPS-67(V)3 (which the NGSSR will replace) had a useful digital automatic target detection, track while scan, and moving target indicator capability from Arleigh Burke Flight I. It is plausible that SPS-67 contributed surface-target tracking data to the Mk 34/Mk 160 architecture, alongside the original SPY-1D, although the exact integration details are not well documented in open sources.
The Arleigh Burke’s current SPQ-9B fire control radar is a later-generation upgrade of that same architectural slot, not the introduction of a function that never previously existed.
If that assessment is correct, then the more interesting question may not be Mk 45 fire control at all, but what is lost—or what is not lost—in the ship's inner-layer anti-ship missile defense architecture by the apparent absence of an SPQ-9B-class firecontrol radar."
If NGSSR (whatever its exact AN/SPS designation turns out to be) is a software-defined, track-capable surface-search radar feeding the Gunnery Control system (GCS) the way I assume that SPS-67(V)3 may have done, then SPY-7(V)3/AEGIS + NGSSR may reproduce the original Burke gun fire-control chain reasonably faithfully — just without the SPQ-9B refinement that more recent Arleigh Burke hulls are getting.
The other half of the picture is the RCN procuring SPEIR and possibly procuring the Mk-20 EOSS (or whatever its CSC-specific successor turns out to be, as I state that noting the USN has an RFI out to replace the Mk20 EOSS ) to go with the BAE Mk45 gun. The Mk 34 Gun Weapon System (GWS) has always paired the radar/GCS chain with an optical sight — Mk 46 OSS on early Flights, Mk 20 EOSS on Flight III — for passive terminal tracking, visual target classification, and ECON-compatible engagement.
SPEIR, now confirmed for Canada (in US Congressional records), via the same FMS case as an electro-optic/infrared (EO/IR) system on surface ships that provides persistent detection and tracking of a wide variety of air and surface targets, in support of multi-mission surface ship operations and defense, looks like it might be filling that role — and may well be almost as capable as the legacy Mk 46/Mk 20 in many respects, particularly given SPEIR's panoramic, persistent-tracking design intent. So between SPY-7/AEGIS, NGSSR, and SPEIR/EOSS, the River Class Mk-45 likely does have a workable fire-control chain — it's just composed of systems that, individually, aren't labeled "gun fire control radar."
Possibly one open area of question is in the layered anti-ship-missile-defense picture, rather than the gun fire control question per se.
On an Arleigh Burke Class with SPQ-9B, I think its possible that radar isn't just feeding the 5" gun — I suspect its part of the ship's broader horizon/clutter anti-ship cruise missile (ASCM) detection layer, working alongside SPY, CIWS, and decoys.
In comparison, current unclassified information suggests the River-class is planned to carry aft two M38-Mod-4 (Bushmaster) 30mm guns, and also carry RIM-116 RAM (midships) and forward RIM-162-block-II ESSM (Mk-41 VLS) together with for ECM the LEED (the active decoy replacing Nulka) that engages further out in the engagement sequence.
With this in mind, if the River Class NGSSR's TWS performance (possibly the SPS-73(v)18 ) against a fast, low-RCS sea-skimmer near the horizon is closer to the original SPS-67(V)3 baseline than to SPQ-9B's enhanced ASMD-tuned performance, that could translate into a somewhat thinner inner-layer radar picture feeding both the 30mm and the Mk-45 in defending against an “attacking missile leaker scenario” — with SPEIR/EOSS picking up more of the terminal-engagement load, than it would had there also been a dedicated SPQ-9B fire control radar on the ship.
To be clear, all of this is massive speculation from a Congressional record (re: FMS), together with RCN River Class sketches/information, that doesn't actually describe combat-system integration — "NGSSR" could turn out to be a more capable system than its US Navy program description suggests, and SPEIR's panoramic IRST-like characteristics may compensate for a lot of this in practice.