The United States is in the process of building (or selling) a number of new missile defense radars focused on coverage over eastern Asia and the Pacific Ocean.  All of these radars will operate in S-Band, which extend from 2 to 4 GHz.  These radars are the Long Range Discrimination Radar (LRDR), the Homeland Defense Radar – Hawaii (HDR-H), the Homeland Defense Radar – Pacific (HDR-P), and the Lockheed Martin Solid State Radars (SSRs) that Japan intends to buy for its two planned Aegis Ashore facilities. Most if not all of these phased-array radars will be built by Lockheed Martin using relatively new Gallium Nitride (GaN) technology.  There is little publicly available information about these radars, so there will not be much in the way of technical details in this post.  This post will also include an update on Raytheon’s new S-Band Air and Missile Defense Radar (AMDR).

The Long Range Discrimination Radar (LRDR)

A previous post discusses the LRDR up until April 2015.  This discussion picks up where that one left off.

In October 2015, the Missile Defense Agency (MDA) awarded Lockheed Martin a $784 million contract to develop, test and build the LRDR.[1]  The objective was to have the LRDR operational at Clear Air Force Station in central Alaska by 2020.  Military construction costs (including a shielded mission control facility, shielded power plant, radar foundation and a maintenance facility) will add another $329 million, bringing the total cost of building the LRDR to over $1.1 billion.[2]  However, it is typically described in the press as a $1.2 billion project.  Construction of the LRDR in Alaska began in September 2017.[3] As of March 2018, “initial fielding” of the LRDR was expected in 2020 with “operational readiness acceptance by the warfighter in the 2022 timeframe.”[4]

According to the MDA: “The LRDR is a midcourse sensor that will improve BMDS target discrimination capability while supporting more efficient used of the GMD interceptor inventory.”[5] [BMDS = Ballistic Missile Defense System; GMD = Ground-Based Midcourse Defense, the United States national missile defense system] The LRDR will also be used for space surveillance.

The LRDR will be a very large phased-array radar operating in S-Band (2-4 GHz), although the actual range of frequencies it will operate over is not publicly known.  (For comparison, the U.S. Navy’s SPY-1 radar used in its Aegis combat system, which is also an S-Band radar used for missile defense (although using different radar technology), operates between 3.1 and 3.5 GHz.)  My post of January 30, 2019 discusses why S-band band was chosen over X-band (8-12 GHz, which could enable greater discrimination capability); it was basically a matter of cost.  The bandwidth and range resolution of LRDR are also not publicly known; it seems possible the range resolution could be as low as 0.5 m or somewhat less. As with the TPY-2 X-band radar and the Aegis SPY-1, the LRDR will certainly have the capability to use Doppler measurements to form two-dimensional (or possibly even three-dimensional) images.

The LRDR will also use dual polarization, which could also potentially be used to obtain some information on a target’s shape.[6] (For example, falling rain drops generally take the shape of oblate spheroids and their eccentricity increases with raindrop size.  Dual polarization weather radars can thus use the ratio of the vertical to horizontal radar reflections to obtain information on the size of the raindrops.)

The LRDR will have two antenna faces, and thus will likely have an azimuthal field of view of about 240°.  See figure 1 below.  As discussed in my January 30, 2019 post, the LRDR has a “wide instantaneous field of view to enable wide area defense.”

Figure 1. LRDR Site Model.  From Richard Hagy (Director, Business Development, Lockheed Martin), “LRDR Program Overview,” March 8, 2017.  Online at: https://ptacalaska.org/wp-content/uploads/2012/09/Lockheed-Martin-LRDR-Project-Update-Richard-Hagy.pdf.

A 2017 article stated that the LRDR will have two 3,000 square-foot antenna arrays (3,000 sq-ft = 279 m²).[7]  According to Chandra Marshall, Lockheed’s LRDR program manager, the LRDR will be about 25 times larger than an SPY-1 antenna.[8]  Assuming this comparison applies to each face of the radars, since a SPY-1 antenna has an aperture of about 12 m², this gives an aperture of about 300 m² for the LRDR.  Thus it appear that each antenna face of the LRDR is larger than that of the Sea-Based X-band radar (SBX, 249 m²) but smaller than those of the Upgraded Early Warning Radars (UEWRs, 384-515 m²) or the Upgraded Cobra Dane radar (660 m²) already in use with the U.S. GMD national missile defense system.[9]  The antenna is populated with T/R modules using relatively new Gallium Nitride (GaN) technology, which provides higher powers and better efficiencies at lower cost than modules based on Gallium Arsenide (GaAs) such as those in the current TPY-2 radars.

According to Carmen Valentino, Lockheed Martin’s Vice President for Naval Radar and Future Systems, the LRDR will be able to see thousands of kilometers, “several times” farther than the two U.S. TPY-2 X-Band radars in Japan.[10]

Lockheed Martin built a scaled-down version of the LRDR at its Solid State Radar Integration Site in New Jersey.[11]  See figure 2.  According to Marshall, this test facility is representative of one radar array panel, whereas the actual radar will have ten array panels.[12]  See figure 3. In October 2018, the test facility successfully tracked a satellite target.[13]

Figure 2: Scaled down (one-tenth the antenna area) version of the LRDR built for testing purposes. Image source: https://news.lockheedmartin.com/2018-10-16-Lockheed-Martin-Reaches-Technical-Milestone-for-Long-Range-Discrimination-Radar.

Figure 3.  Illustration showing of how the LRDR antenna is comprised of ten stacked antenna panels.  Image source: https://www.portlandbolt.com/about/projects/government-and-military/long-range-discrimination-radar-equipment-shelter/.

The LRDR antenna is comprised of a number of self-contained transmit and received units that are grouped together in blocks. Although the size and number of these blocks is not publicly known, the LRDR will use thousands of such blocks.[14]  This approach allows the radar to be serviced by removing and replacing a block while the rest of the antenna continues to operate.[15] This approach not only decreases potential down time for the radar, but also contributes to the scalability of the LRDR technology.  All the other Lockheed Martin radars discussed in this post are based on this LRDR technology.

The Homeland Defense Radar – Hawaii (HDR-H)

U.S military officials have always insisted that Hawaii is protected by the existing sensors and Ground Based Interceptors (GBIs) of the GMD national missile defense system.[16]  However, a look at any globe makes it clear that there will be significant gaps in the radar coverage of a missile flying from North Korea to Hawaii and the GMD system’s GBIs in Alaska and California will have long flyouts to reach intercept points. (The Sea-Based X-band operates out of Honolulu but has a number of serious limitations including questionable reliability and a very limited electronic field of view. In addition, it will need to be dry-docked for an extensive overhaul in the not too distant future.[17]) Taken together with the fact that Hawaii is significantly closer to North Korea than any other part of the United States (except for Alaska), this situation has led to frequent calls to improve Hawaii’s defenses by deploying either interceptors or a new radar (or both) there.

Interceptors could be deployed in Hawaii in the near future either by stationing a THAAD battery there or by converting the existing Aegis Ashore test facility to an operational system equipped with SM-3 Block IIA interceptors.  However, the SPY-1 radar of the Aegis Ashore site is insufficient to support Block IIA interceptors, and as discussed below, MDA apparently also does not consider THAAD’s TPY-2 X-band radar as being adequate for defending Hawaii.  So far, no decision has been made (or at least publicly announced) to deploy any interceptors in Hawaii, although the 2019 Missile Defense Review did mandate a study of the feasibility of operationalizing the Aegis Ashore site and the development of an emergency activation plan to do so.

In order to assess its future sensor needs, MDA carried out a Sensor Analysis of Alternatives. The findings of this analysis were presented to the Missile Defense Executive Board in October 2016.[18]  According MDA Director Lt. General Samuel A. Greaves:

“The Sensors Analysis of Alternatives (AOA), conducted by the Department to assess the most cost-effective options for enhanced sensor capability to increase Ground Based Interceptor capability against future, complex threats, highlighted the operational value of placing additional discrimination radars in the Pacific. Based on the Sensor AOA finding, MDA completed site surveys for the Homeland Defense Radar – Hawaii (HDR-H) in FY 2017.”[19]

The Sensor AOA (or possibly a subsequent study) concluded that a TPY-2 radar would not be adequate for Hawaii’s defense requirements.[20]  According to Gary Pennet, the MDA Director of Operations, the HDR-H “will probably not be quite the scale of an LRDR, but definitely something more than an AN/TPY-2.[21]

According to the MDA:

“The HDR-H radar will provide a persistent long-range acquisition and discrimination capability, augmented by other sensors, to mitigate the effects of evolving threats to the BMDS.  The HDR-H optimizes discrimination in the Pacific architecture and increases the ability of GBIs to enhance the defense of Hawaii.  The radar also supports additional mission areas including Space Situational Awareness.”[22]

Note that while this description of HDR-H’s purpose only refers to supporting GBIs, it would also be able to support any SM-3 or THAAD interceptors deployed in Hawaii.

The total cost of the HDR-H is expected to be about $1 billion, with $763 million to design and build the radar and $32I million for design and construction.  The HDR – H is the first of what could be as many three homeland defense radars, costing a total of $4.1 billion.[23] The second radar will be the $1.3 billion HDR-P, which will be discussed in the next section.  I have not seen any discussion of what and where a potential third HDR might be.

In December 2018, MDA awarded Lockheed Martin a $585 million contract to design and build the HDR-H.[24] The HDR-H will be a scaled-down, single-face version of the LRDR.  See Figure 4 below. The HDR-H  is expected to complete “initial fielding” in FY 2023 for “BMDS system integration, testing and readiness for operations.”[25]

Figure 4.  Artist’s rendering of the HDR-H?  A December 18, 2018 Lockheed Martin press release contained an artist’s rendering of the HDR-H.[26]  This image was subsequently removed from the posted press release, and a note was added that read: “In the original version of this release, Lockheed Martin published a rendering of the Homeland Defense Radar – Hawaii (HDR-H).  Lockheed Martin was not authorized by the Missile Defense Agency to publish this rendering, and it should not be considered an accurate representation of the final project. The future site of HDR-H has not been chosen.  The rendering has been removed and Lockheed Martin regrets the error.”  Figure 4 seems likely to be the removed rendering, as it appears on several websites together with some or all of the Lockheed Martin press release. Figure 4 image source: “Lockheed to Design, Develop and Deliver US Homeland Defense Radar in Hawaii,” www.everythingrf.com, December 20, 2018. Online at: https://www.everythingrf.com/News/details/7382-Lockheed-to-Design-Develop-Deliver-US-Homeland-Defense-Radar-in-Hawaii.

The MDA has narrowed the deployment site for the HDR-H to three possible locations on the northwest coast of Oahu. See Figure 5 below.

Figure 5.  Possible deployment sites for the HDR-H.  Two of the sites are in the U.S. Army’ Kahuku Training Area and the third is next to the U.S. Air Force’s Kaena Point Satellite Tracking Station at Kuaokala Ridge.  Image source: Missile Defense Agency, “HDR-H EIS Posters,” Online at: https://www.mda.mil/global/documents/pdf/HDR_H_EIS_Posters_5June2018.pdf.

Homeland Defense Radar – Pacific (HDR-P)

The second radar to come out of the Sensor Analysis of Alternatives is the HDR-P.  On 7 December 2018, the MDA awarded three companies (Lockheed Martin, Northrup Grumman and Raytheon) $250,000 contracts to analyze HDR-P performance requirements, with the results due in April 2019.[27] Possible locations for the HDR-P had already been selected, but were classified.[28]

According to the MDA: “The HDR-P provides persistent midcourse discrimination, precision tracking and hit assessment to support the defense of the homeland against long-range missile threats.”[29]  As with the LRDR and HDR-H, it may also be used for space surveillance.

In December 2018, it was reported in the Japanese press that the United States was considering deploying the HDR-P in Japan beginning in 2023.[30]  A January 2019 Japanese newspaper article indicated that the U.S. government had not yet requested Japanese permission to deploy the radar in Japan, but intended to so soon.[31] It also added that the United States intended to share information from the radar with the Japanese military.

The HDR-P will be more expensive than the HDR – H, costing over $1.3 billion, with $1.0 billion for the radar and $321 million in military construction costs. Thus it will cost essentially the same as the LRDR.

Japan’s Aegis Solid State Radar (SSR)

In June 2017, Japan’s Defense Ministry announced plans to deploy two Aegis Ashore ballistic missile defense facilities on Japanese territory.  The United States has deployed an Aegis Ashore facility in Romania, is building one in Poland, and has an Aegis Ashore test facility in Hawaii. See Figure 6 below.  The Japanese Defense Ministry stated that it had chosen Aegis Ashore over the potential alternative Terminal High Altitude Area Defense (THAAD) system primarily on the basis of cost.  Covering all of Japan against North Korean ballistic missiles would require two Aegis Ashore facilities costing about $720 million each (not including the SM-3 Block IIA interceptor missiles) whereas six THAAD batteries, at a cost of $900 each (this price appears to include the interceptor missiles), would be needed for the same coverage.[32] See Figure 7 below.  In December 2017, the Japanese government formally approved the purchase of the two Aegis Ashore systems.[33] At the time, plans called for both systems were to be deployed by the end of 2023.

Figure 6.  The deckhouse of the U.S. Aegis Ashore facility in Romania.  Two of the four SPY-1 radar antenna faces are visible. Image source: Missile Defense Agency.

Figure 7. Planned locations and notional coverage of Japan’s Aegis Ashore sites.  Image source: Kunihiro Hayashi, Haruna Ishikawa, Hirotaka Kojo and Shinichi Fujiwara, “Prefectures Now Question Need for U.S. Missile Defense System,” The Asahi Shimbun, June 25, 2018.

The Japanese Defense Ministry considered two different radar options for their Aegis Ashore systems. One was the SPY-6 Air and Missile Defense Radar (AMDR) scheduled to begin deployment on U.S. Navy Aegis Flight III destroyers starting in 2023. The AMDR is a four-faced, solid-state S-Band phased-array radar manufactured by Raytheon. The AMDR is a considerably more powerful radar than the SPY-1 radar on current U.S. Aegis ships (see the next section). The other radar considered was the Solid State Radar (SSR), a Lockheed Martin radar that uses the same S-Band technology as the LRDR, although the SSR is obviously much smaller than the LRDR. In January 2018, Lockheed Martin announced that it had successfully demonstrated connecting a radar using LRDR technology to an Aegis Ashore system.[34] In the same press release, it stated that the “Lockheed Martin SSR, including very robust participation from Japanese industry, is one of the configuration options available to Japan for its upcoming Aegis Ashore installations.”

In July 2018, Japan announced that it had selected the SSR as the radar for the Aegis Ashore systems.[35]  The detection range of the radar was reportedly the decisive factor in selecting the SSR, although lifecycle cost was also a factor.[36]  The detection range of the SSR was said to be far more than 1,000 km.[37] The possibility that the SSR might be available for export from the United States before the AMDR would be has also been raised as a possible factor in the radar choice.[38]

By mid-2018, the cost of the Japanese Aegis Ashore facilities had increased significantly, largely due to the greater cost of the SSR relative to the AMDR.  Each site was now expected to cost about $1.2 Billion, not including the SM-3 Block IIA interceptors and their launchers.[39]  Thirty years maintenance and operations would add an additional $0.9 billion per site.  In addition, initial operation of the of the first Aegis Ashore site now appears to have been delayed until about 2025 due to the time required to deliver the radar.[40]  On January 29, 2019, the State Department approved the sale of the two Aegis Ashore system to Japan.[41]

 

The Air and Missile Defense Radar (AMDR)

The AMDR is a new radar system that is to be deployed on the U.S. Navy’s new Flight III Aegis destroyers starting in about 2023.  The AMDR consists of Raytheon’s S-Band SPY-6(V)1 radar for air and missile defense, a smaller X-band radar for surface and horizon search and a common control system. I will not discuss the X-band radar here and will use the terms AMDR and SPY-6(V)1 interchangeably.  My blog post of January 30, 2013 describes the AMDR and this discussion updates that post.

In the Pacific, U.S. Aegis destroyers are homeported at four bases: Pearl Harbor (Hawaii), Yokosuka (Japan), San Diego (California) and Everett (Washington).

Like the SPY-1 radar it will replace, the AMDR will operate in S-band (the precise range of frequencies is not publicly available) and will have four antenna faces to provide 360° coverage.  Unlike the SPY-1, which uses central vacuum-tube-based transmitters to drive one or more entire antenna faces, the AMDR (like the LRDR and the other radars discussed above) will be a solid-state active-array radar, with each antenna face populated with a large number of transmit/receive (T/R) modules.  Also like the other radars discussed above, the AMDR’s T/R modules use relatively new GaN technology.

Each antenna face of the AMDR has a diameter of about 14 feet (4.3 m), somewhat larger than that of the SPY-1 antenna which has dimensions of about 3.8 m x 3.7 m.[42]  Although a number of Navy studies indicated that that a larger and more powerful radar was needed to meet future requirements, the Navy concluded that the 14 foot diameter radar was the largest that would fit on an Aegis destroyer hull.[43]

The AMDR antenna is built up by combining a number of radar modular assemblies (RMAs), which Raytheon describes as: “Each RMA is a self-contained radar in a 2’x2’x2’ box. The RMAs can stack together to form any size array to fit the mission requirements of any ship.”[44] The AMDR uses 37 RMAs as can be seen in Figure 8 below.  Thus the antenna area of a single AMDR antenna is thus about 37 x 2’ x2’ = 148 square feet = 13.8 m². (For comparison, the antenna area for on face of the SPY-1 is about 12 m².[45])

Figure 8.  A full-size AMDR radar face built for testing purposes. The outlines of the 37 two-foot-square RMAs are clearly visible. Raytheon photograph from Richard Scott, “Beneath the Skin:  US Navy DDG-51 Flight III Guided Missile Destroyer,” Jane’s Defence Weekly (content preview).  Online at: https://www.janes.com/images/assets/731/51731/US_Navy_DDG_51_Flight_III_guided_missile_destroyer.pdf.

The sensitivity of the AMDR has been described by the Navy as “SPY + 15.”[46]  This means that the sensitivity of the AMDR is 15 decibels (dB) greater than that of current SPY-1 version (the SPY-1D(V)). Since 15 dB  = 32, the AMDR is frequently described as being about 30 times more sensitive than the current Aegis SPY-1. Alternatively, the AMDR is described as being able to detect a target with half the radar cross section at twice the distance relative to the current SPY-1 radar.  Recently there have been some indications that the AMDR may somewhat exceed this level of performance.  A January 2019 Navy Fact Sheet says the SPY- 6(V)1 sensitivity will be greater than that of the current SPY-1 by a factor of 16dB (16 dB = 40).[47] That same month, Scott Spence, the Senior Director of Raytheon’ Naval Radar Systems, stated that: “It’s 70 times more sensitive than the current radar.”[48]

In June 2016, a full-scale production-representative AMDR radar (single-face) was delivered to the Pacific Missile Range Facility for land-based testing against a variety of targets.[49] See Figure 8. This radar had its first successful test against a ballistic missile target in March 2017.[50] On January 31, 2019, it completed its developmental test program with its 15^th successful test against a ballistic missile.[51]

The first Flight III Aegis destroyer (DDG 125, USS Jack H. Louis) is under construction and is scheduled for an initial operational capability in 2023.  In addition, the Navy currently plans to replace the SPY-1 radars on its Flight IIA destroyers with a smaller version of the AMDR SPY-6(V)1.  This version, designated SPY-6(V), will have 24 RMAs per 12 foot radar face, and a sensitivity of SPY +11, or about 13 times that of the current SPY-1.[52]  Currently 38 of the Navy’s 66 Aegis destroyers are Flight IIAs, with nine more under construction.[53]

The Enterprise Air Surveillance Radar (EASR) will also use AMDR technology, even though it may not have any missile defense role.[54]  The EASR will use 9 RMAs and have a sensitivity about equal to the current SPY-1 radar.  There will be two variants of the EASR. A single-face rotating version designated SPY-6(V)2 will be deployed on future amphibious assault ships, starting with the LHA-8 (USS Bougainville).  A version with three fixed faces, designated SPY-6(V)3, will be deployed on future aircraft carriers, starting with CVN-79 (the USS John F. Kennedy).  The EASR is scheduled to begin developmental testing in the third quarter of FY 2019.

Figure 9. From right to left: (1) a single RMA, (2) a nine RMA EASR antenna (SPY +0), (3) a 37 RMA AMDR antenna (SPY+15), and (4) a 69 RMA antenna (SPY+ 25).  It is unclear to me if the largest antenna corresponds to any proposed system. Image source: Raytheon Company, “AMDR Infographic.” Online at: https://www.raytheon.com/sites/default/files/capabilities/rtnwcm/groups/public/documents/image/amdr-infographic-pdf.pdf.

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[1] Mike Gruss, “Lockheed Martin Lands Missile Defense Radar Contract,” Space News, October 15, 2015.

[2] Missile Defense Agency, Fiscal Year (FY) 2019 Budget Estimate: Overview, March 2018, p. 6. Online at: https://www.mda.mil/global/documents/pdf/budgetfy19.pdf.

[3] Lockheed Martin Corporation, “Lockheed Martin Reaches Technical Milestone for Long Range Discrimination Radar,” News Release, October 16, 2018. Online at:  https://news.lockheedmartin.com/2018-10-16-Lockheed-Martin-Reaches-Technical-Milestone-for-Long-Range-Discrimination-Radar

[4] Ibid.

[5] MDA, “FY 2019 Budget Overview,” p. 6.

[6] Sydney J.  Freedberg, Jr., “New Missile Defense Radar Passes Key Stage,” Breakingdefense.com, April 10, 2017; Jason Sherman, “MDA Approves Preliminary Design, ‘Dual-Pol’ Tech for Long Range Discrimination Radar,” Inside Defense SITREP, April 21, 2017.

[7] Marcus Weisgerber, “Pentagon Eyes Missile-Defense Sensors in Space,” Defense One, August 30, 2016.

[8] David B. Larter, “Here’s the Latest on Lockheed’s Massive Long-Range Anti-Ballistic Missile Radar,” Space News, December 9, 2019.

[9] For antenna apertures, see:  “Appendix 10: Sensors” of Laura Grego, George N. Lewis, and David Wright, Shielded from Oversight: The Disastrous US Approach to Strategic Missile Defense, Union of Concerned Scientists, July 2016.  Online at: https://www.ucsusa.org/sites/default/files/attach/2016/07/Shielded-from-Oversight-appendix-10.pdf.

[10] Weisgerber, “Pentagon Eyes.”

[11] “Lockheed Martin Reaches Technical Milestone for Long Range Discrimination Radar,” Space Daily, October 22, 2018.

[12] Jason Sherman, “MDA Approves Long Range Discrimination Radar for Full-Rate Production,” Inside Defense SITREP, October 17, 2018.

[13] Ibid.

[14] Lockheed Martin, “Lockheed Martin Demonstrates Next Generation Aegis Ashore Solution,” News Release, January 11, 2018.  Online at: https://news.lockheedmartin.com/2018-01-11-Lockheed-Martin-Demonstrates-Next-Generation-Aegis-Ashore-Solution.

[15] Lartner, “Here’s the Latest.”

[16] See, for example, quotes 22, 34 and 36 in George Lewis, “Updated List of Claims about GMD Effectiveness,” mostlymissiledefense blog, May 31, 2018. Online at: https://mostlymissiledefense.com/2018/05/31/updated-list-of-claims-about-gmd-effectiveness-may-31-2018/.

[17] Jen Judson, “MDA: Even Without Sea-Based Radar, We Can Still Detect Missiles in the Pacific,” http://www.defensenews.com, June 9, 2017.

[18] Director, Operational Test and Evaluation, FY 2017 Annual Report, January 2018, p. 285. Online at: http://www.dote.osd.mil/pub/reports/FY2017/.

[19] Lieutenant General Samuel A. Greaves, Written Statement, Strategic Forces Subcommittee, House Armed Services Committee, April 17, 2018, p. 10. Online at: https://www.mda.mil/global/documents/pdf/FY19_Written_Statement_HASC_SFS.pdf.

[20] Jason Sherman, “DOD Advances Plan for New $747 Million Hawaii Missile Defense Radar,” Inside Defense SITREP, June 7, 2017.

[21] Ibid.

[22] MDA, “FY 2019 Budget Overview,” p. 6.

[23] Jason Sherma, “Source Selection for $1 Billion Hawaii Ballistic Missile Radar Expected this Month,” Inside Defense SITREP, December 12, 2018.

[24] Lockheed Martin Corporation, “Missile Defense Agency Awards Lockheed Martin Contract to Design, Manufacture and Construct Homeland Defense Radar – Hawaii,” Press Release, December 18, 2018.   Online at: https://news.lockheedmartin.com/2018-12-18-Missile-Defense-Agency-Awards-Lockheed-Martin-Contract-to-Design-Manufacture-and-Construct-Homeland-Defense-Radar-Hawaii

[25] MDA, FY 2019 Budget Overview, p. 6.

[26] Lockheed Martin Corporation, “Missile Defense Agency Awards.”

[27] Jason Sherman, “MDA Launches New Pacific Radar Studies in Advance of Planned $1 Billion Project,” Inside Defense SITREP, January 24 2019.

[28] Ibid.

[29] Missile Defense Agency, “FY 2019 Budget Overview,” pp. 6-7.

[30] Jiji News Agency, “U.S. Plans to Deploy New Homeland Defense Radar System in Japan from 2023,” The Japan Times, December 24, 2018.

[31] “U.S. Eyes Anti-ICBM Radar on Japan Soil,” The Japan News, January 29, 2019.

[32] Elizabeth Shim, “Japan Says No to THAAD Battery as China Announces Drills,” UPI.com, June 23, 2017.

[33] Mari Yamaguchi, “Japan Approves Missile Defense System Amid NKorea Threat,” Associated Press International, December 19, 2017.

[34] Lockheed Martin, “Lockheed Martin Demonstrates.”

[35] Nobuhiro Kubo, “Japan Picks Lockheed Martin Radar for Missile Defense System: Ministry Official,” Reuters, July 2, 2018.

[36] “Govt to Install New Radar System in Aegis,” The Japan News, July 4, 2018; Kubo, “Japan Picks.”

[37] “Govt to Install.”

[38] Franz-Stefan Gady, “Japan Selects Lockheed Martin Solid State Radar for New Ballistic Missile Defense Systems,” The Diplomat, July 31, 2018.

[39] “Japan to Spend $4.2 Billion on Lockheed Radars for Aegis Ashore Missile Defense,” Defence Monitor Worldwide, August 1, 2018.

[40] Shinichi Fujiwara, “Costs Balloon, Delays Expected for Aegis Ashore System,” The Asahi Shimbun, July 31, 2018.

[41] Jason Sherman, “State Dept. Approves Potential $2.1B Aegis Ashore Sale to Japan,” Inside the Navy, February 4, 2019.

[42] Grego, et. al., “Appendix 10: Sensors,” p. 5.

[43] Grego, et. al., “Appendix 10: Sensors,” pp. 6-7.

[44] Raytheon Company, “AN/SPY-6 Air and Missile Defense Radar,” Fact Sheet. Online at: https://www.raytheon.com/capabilities/products/amdr.

[45] Grego, et. al., “Appendix 10: Sensors,” p. 5.

[46] Government Accountability Office, “Arleigh Burke Destroyers: Additional Analysis and Oversight Required to Support the Navy’s Future Surface Combatant Plans,” GAO-12-113, January 2012, pp. 41-43.

[47] U.S. Navy, “Air and Missile Defense Radar (AMDR), Fact Sheet, January 10, 2019.  Online at: https://www.navy.mil/navydata/fact_display.asp?cid=2100&tid=306&ct=2.

[48] Mallory Shelbourne, “Navy Official: AMDR ‘Successfully Performed’ in 14 Ballistic Missile Tests,” Inside Defense SITREP, January 17, 2019.

[49] Justin Doubleday, “Air and Missile Defense Radar Arrives in Hawaii for Testing,” Inside Defense SITREP, June 22, 2016; Jason Sherman, “Pentagon Clears Navy’s Air and Missile Defense Radar for Initial Production,” Inside Defense SITREP, May 4 2017.

[50] U.S. Navy, “U.S. Navy Successfully Conducts AN/SPY-(6) Air and Missile Defense Radar Ballistic Missile Test, News Release, February 2, 2019.

[51] Ibid.

[52] U.S. Navy, “Air and Missile Defense Radar (AMDR).”

[53] U.S. Navy, “Destroyers – DDG,” Fact Sheet, January 23, 2019. Online at: https://www.navy.mil/navydata/fact_display.asp?cid=4200&tid=900&ct=4.

[54] Raytheon Company, “Enterprise Air Surveillance Radar,” Fact Sheet, 2019. Online at: https://www.raytheon.com/capabilities/products/easr; Geoff Fein, “Surface Navy 2019: USN Set to Receive First Raytheon EASR for Testing,” partial article, Jane’s 360.  Online at: https://www.janes.com/article/85719/surface-navy-2019-usn-set-to-receive-first-raytheon-easr-for-testing.