Singha wrote:What is the point of a 500km tracking if still subject to earth curvature los limit?
At 500km out its radar floor height will be quite high and vlo bogies can still sneak around
The height of the mast mount aint changi
AEGIS Baseline 9.0 that is currently operational ushered in concurrent IAMD for the US Navy i.e. the BMD ships (Destroyers and Cruisers) upgraded with BL-9 can perform both the Ballistic Missile Defense, and Maritime point and Area Defense mission concurrently.
Meanwhile, the capability to execute exoatmosheric intercepts has increased dramatically both in terms of the threats (Target missile performance), all out range, and altitude coverage. SM-3 Block 1B, and SM-3 Block 2A increase that dramatically.
Another point that is often overlooked is that with the upcoming induction of the SM3 IIA, the US Navy will be able to cover pretty much all of LEO as far as an ASAT capability/role is concerned and with ships deployed around the world this opens up a lot of flexibility as a retaliatory action if someone starts to attack US space assets. SM3 IA has already demonstrated real ASAT capability more than a decade ago but this is not something they talk about very often but it isn't hard to do the math if one counts the number of fielded interceptors and number of available cells on DDGs available for growth.
Also, not sure where the 500km figure comes from as it is not an accurate representation when you are talking about a higher power 5000+ T/R module GaN S-Band face and an overall >50% increase in Power Supply relative to DDG-51 Flt. II. Best estimates for Ballistic Missile Warhead (RCS 0.03 m2) detection capability of the SPY-1 is around 300-350 km. The SPY-6 was required to track half the RCS at twice the range so you can develop a rough sense of what ranges it can get you if you hold warhead RCS constant.
You are looking at a 14 foot wide antenna and a 4th generation AESA ( 37 RMA SPY-6) compared to a 12 foot wide PESA (SPY-1) .
Currently, the DDG can use forward deployed AN/TPY-2's for cuiing SM3's and are able to Launch SM3s on Remote before a ballistic Missile comes into the field of view of their SPY-1 radars (or it may not come into its FOV ever and the PIP is calculated and communicated to the interceptor by cooperative engagement). In the future with the SPY-6, with greater range, the reliance on forward deployed TPY-2s will be reduced as organic capability will be enhanced.
Additionally, with AEGIS Baseline 9 and beyond the US Navy now has NIFC-CA so the interceptor performance need not be restricted to SPY-1/6 radar horizon limitation as Launch on Remote, Forward Pass and Cooperative Fire Control level targeting is possible with the EA-18G, F-35C, E-2D and even with other forward deployed sips (Using E-2/EA-18G as gateways). CEC and NIFC-CA are the reason why the US Navy is buying 70 E-2Ds; It is not just to provide AEW to the Carrier Strike Group but to enable cooperative targeting using SM6 and future interceptors. Expect the "gateway" TTNT capability to also come on the Triton's via later upgrades.
Using NIFC-CA and either MADL (F-35) or TTNT data-link (EA-18G and E-2D) the Aegis ships with BL 9 can launch SM6 missiles even if the intended targets are outside their radar's horizon. This capability has already been fielded and it has been demonstrated on multiple occasions (Google - NIFC-CA).
The US Navy is now looking to a larger SM6 by upgrading its main motor to match the diameter of the SM3 Block 2A which should take its maximum range against subsonic or low supersonic targets to beyond 450-500 km for OTH targeting and should allow it to provide terminal defense against IRBM class missiles vs MRBM capability fielded with the existing SM6 missiles.
Finally, the US Navy and the Missile Defense Agency was ordered by the US Congress to demonstrate intercept capability of the SM3 Block IIA against a simple ICBM (exact language of the mandate below)
US 2018 Budget wrote:...not later than December 31, 2020 conduct a test to evaluate and demonstrate, if technologically feasible, the capability to defeat a simple intercontinental ballistic missile threat using the standard missile 3 block IIA missile interceptor.
^ If the Congress demands this capability from US Navy's deployed ships then one logical way to achieve this would be to require the much larger 69 RMA AMDR on the future large surface combatant which the US Navy has just begun working on for fielding in the next decade.
Singha wrote:May have some use in tbmd but how so vs sea skimmers and low flying manned platforms ?
The sea skimming threat will only partially be dealt with the SPY-6 and its of shoots. There is a dedicated X-Band radar for that, and the US Navy also plans on fielding a new GaN X-Band Radar (AN/SPQ-9B replacement) as an upgrade to this capability so that it can buddy up with SPY-6 and its derivatives on all destroyers and frigates. Although both radars are multi-mission, there is usually a distinction in terms of the specific missions they perform to support BMD, Point and fleet Area defense needs and other duties (ATC, Periscope detection.. etc).