The SteelNavy.Com Message Board: Re: The Radar discussion

Quote: "I found no indication that the SPS-73(V)18 is designed to detect airborne targets. This is not emphasised in the company's description or any other description."

In this:

https://www.defenseadvancement.com/news/u-s-navy-ngssr-completes-developmental-testing-milestone/

Is this:

"Through upgradeded/modifiable technology and a high system operational availability, it offers ship defense against current military threats for surface and limited low altitude air targets, while also addressing risks inherent in operating in littoral waters and vulnerabilities such as submarine attacks."

Limited low altitude air targets...

So, it's not a "pure surface radar" putting it into opposition with "a radar designed to search for air targets." Because, "The AN/SPQ-9B detects sea skimming missiles at the horizon even in heavy clutter while simultaneously providing detection and tracking of surface targets and beacon responses." From this excellent source:

https://man.fas.org/dod-101/sys/ship/weaps/an-spq-9.htm

Please note that SPQ-9B has three modes, one being surface search. While NGSSR has air detection abilities... What distingushes them is "basic function," not what they detect. NGSSR is a navigation radar. SPQ-9B is a (target) tracking radar. NGSSR was developed after two major US Navy collisions. It provides enhanced navigation "situational awareness." It sees more things--surface and air--through clutter better than the previous systems it replaces. It aids the bridge with safer navigation. SPQ-9B scans the horizon, and is particularly sensitive to fast incoming contacts from the horizon. It's linked into AEGIS and fire control. It tracks contacts for weapons engagement.

You are correct that the one does not and can not replace the other. They complement each other, with overlap in their two functions. It is stated that NGSSR replaced a list of older navigation radars, while FXR is the stated SPQ-9B replacement. FXR will be an active phased array. NGSSR is not. They're not competing.

From:
https://en.wikipedia.org/wiki/AN/SPY-6

"In September 2010, the Navy awarded technology development contracts to Northrop Grumman, Lockheed Martin, and Raytheon to develop the S-band radar and radar suite controller (RSC). X-band radar development reportedly will come under separate contracts."

And:

"To cut costs, the first 12 SPY-6 sets will have an X-band component based on the existing SPQ-9B rotating radar, to be replaced by a new X-band radar in set 13 that will be more capable against future threats.[8]"

SPY-6 is currently only S band. SPQ-9B is only an interim add-on. The original intent, though, was to create a system with both together. FXR could then be viewed as the intended replacement component, and part of the dual band system, though developed under separate contract, and coming later as a result. My view, however, is the same as yours. FXR replaces SPQ-9B, and is separate from SPY-6.

Previous Message

You emphasise that the SPQ-9B can detect surface targets. We agree. We also agree that the SPQ-9B is capable of detecting and tracking air targets. This is its main function.

I found no indication that the SPS-73(V)18 is designed to detect airborne targets. This is not emphasised in the company's description or any other description.

I think there's a difference between a pure surface radar and a radar designed to search for air targets. A surface radar produces a narrow beam that scans the surface of the water. By 'narrow', I mean that it is not high on the Z axis. See also the shape of the antennas, which are very low. I don't know the shape of the SPS-73(V)18, but it probably isn't much different because the radome is still not very high. I think this is done to limit radar emissions and thereby reduce the probability of detection. This is not possible with a radar designed to search for air targets. The radar beam has to be wider (higher). Consequently, the SPQ-9B antenna is much higher than that of typical surface radars (e.g. SPS-67 and the older SPS-73).

You are right that the SPQ-9B is probably not a phased array radar. I'm not sure why I thought it was.

Regarding the X and S bands in the case of the SPY-6, I also found this text claiming that it consists of the X and S bands. However, the statement that the SPQ-9B is the X-band component in the first sets is irritating. To me, this can only be understood to mean that SPY-6 is an S-band radar. The X-band radar must be a different one. This could be either the SPQ-9B or the Future X-Band Radar (FXR).