Comparing the Air/Surface Search Radar Options for the Philippine Navy's Future Frigate versus Technical Specifications

For the past 2 years since 2016, MaxDefense had been discussing the Frigate Acquisition Program for the Philippine Navy, including the fact that Hyundai Heavy Industries (HHI) submitted 2 options for the different subsystems of the frigates.

While the Combat Management System (CMS) was discussed too publicly to the point that it even became a nationwide issue, which we all know what happened next. MaxDefense also mentioned several times especially in our Facebook posts that the CMS issue is just the tip of the iceberg, as the CMS affects most of the important subsystems like the sensors and surveillance systems of the frigates.

Aside from the CMS, another subsystem where HHI submitted 2 options is the Air/Surface Search Radar (ASSR), which is the most important surveillance sensor of the frigates. MaxDefense will discuss about the ASSR in this blog entry.

The Airbus (now Hensoldt) TRS-3D, which is among the 2 options provided by HHI for the Air/Surface Search Radar (ASSR) requirement, and HHI's preferred choice.
Photo taken from Hensoldt's website.

The other option HHI submitted for the frigate's ASSR is the Thales Nederland NS100 series of 3D AESA naval radar, one of the latest naval radars in the market today.
Photo taken from Thales' website.

The Air/Surface Search Radar System:

The Philippine Navy released an initial version of the Technical Specifications prior to the 1st Stage Bidding of the Frigate held on 04 December 2013. MaxDefense was able to discuss it in a blog entry for the frigate:

"Philippine Navy Frigate Acquisition Project - An Anaysis of the 1st Stage Bidding Specifications" - dated 09 October 2013.

MaxDefense believes that the initial specs were too general and too basic, and shows total lack of understanding on the subsystem. It also separated the requirements for air search and surface search, despite current technology having a single radar system that covers both requirements.

This was later on replaced by a more specific Technical Specifications. Not only did it combined the air search and surface search requirements into a single system, but it increased the performance values too.

This new requirements was also discussed in a previous MaxDefense blog entry:

"The Philippine Navy's Frigate Acquisition Program Finally Moves in 2016! New Technical Specification Released And Tender Soon" - dated 07 February 2016

Below shows the Technical Specifications as of 2013 (left) and 2015 (right) for the Air/Surface Search Radar as shown on the Supplemental Bid Bulletin Nr. DND/PN-FAP-16-01 released on 02 February 2016. The same can be seen on Page 26 of the Statement of Compliance form as provided under Supplemental Bid Bulletin Nr. DND/PN-FAP-16-03 released on 17 February 2016.

This is the Technical Specifications for the Air/Surface Search Radar (ASSR) system. The left is the old specs used in the 1st Stage bidding, and the right one is the updated specs used in the 2nd (and final) Stage Bidding, which is the prevailing version of the technical specs. No additional capabilities were added later on.
Photo cropped from the SBB No. DND/PN-FAP-16-01 dated 2 February 2016.

Important Points of the ASSR Technical Specifications:

Among the most important points of the ASSR's Technnical Specs are as follows:

1. Instrumented Range - should be at least 100 nautical miles for air targets and 40 nautical miles for surface targets.

This means that the radar should, at its maximum capability in the best weather (clear) conditions, should be able to see air targets of any size 100 nautical miles away from the radar (or the ship in general), or a surface target of any size from 40 nautical miles away from the radar. Surface target could be anything in the sea surface or the ground surface. This the most common feature that is used to determine if a radar system is superior over the another system, although in reality this should not be the case.

Take note: Surface targets only require a smaller range as radars detection of surface targets is limited due to the Earth's curvature. Microwave beams travel in straight lines/path.

Converting to kilometers, 40 nautical miles = 74.08 kilometers, while 100 nautical miles = 185.2 kilometers.

2. Tracking Capacity - should be at least 750 tracks for air and surface tracks.

The radar should be able to detect and track (or see) at least 750 air and surface targets at any given time. This is very useful in areas with high volume of military and commercial sea and air traffic like the South China Sea/West Philippine Sea where large commercial and naval ships are mixed up with small fishing boats, plus a large volume of commercial airline flight routes mixed up with military aircraft. MaxDefense believes that 750 tracks is a decent capability considering most new surveillance radar systems can track more than that.

3. Detection Range - minimum of 200 meters up to a maximum of instrumented range 

This means that aside from the ASSR to be able to see naval and ground targets at 40 nautical miles away, and air targets at 100 nautical miles away from the ship, the ASSR should also be able to see such targets to as close as 200 meters away from the ship. Radar systems do not normally see any target very close to the transmitter itself (like a ship berthed side by side with the ship it is equipped), and detection can only be made from a certain distance.  Surprisingly, the 200 meter requirement is considered too much since most modern radars can have a minimum range of less than 100 meters.

4. Azimuth Coverage - 360 Degrees

This means that the radar's maximum detection coverage allows it to see targets in all directions, which also means that the radar antenna has the capacity to turn at 360 degrees to be able to do this. This is standard in today's radar technology although it is right to include it in the technical specs.

5. Transmitter - Solid State

Solid state refers to the technology used for the radar system to transmit microwave signals. It is the current technology used in radars, replacing the old Magnetron-based technology whose performance is not as good, is less reliable, requires more power to use, and is physically larger and heavier, among others.

6. The Radar is primarily used for air and surface surveillance and acquisition and must be capable of quickly detecting and accurately locating air and surface contacts, and detection of sea skimming missiles at a minimum altitude of 10 feet to allow fire control resources sufficient time to lock-on and engage

This is a specification forgotten by many other discussions online about the Frigate's ASSR. The desciption is actually divided into two parts. First is the description of the ASSR, while the second part (underlined) is the actual specification, which is for the ASSR to be able to detect sea-skimming missiles at a minimum altitude of 10 feet.

MaxDefense believes that despite these requirements in the technical specification, it still lack enough information that allows it to be more specific to what it really requires. Among them include the lack of requirement on the radar's detection chance of specific targets with a given Radar Cross Section in a certain environment model, or the maximum elevation azimuth coverage of the radar system, both of which are also very important requirements.

This photo above was cropped from the Computer Generated Image provided by Hyundai Heavy Industries (top) of what the Philippine Navy's future frigate may look like once completed. Surprisingly, the ASSR antenna is strikingly the same as the antenna of the Thales Nederland NS100. Anyone could compare the antenna profile since there are numerous online photos of what the antennas of TRS-3D and NS100 look like.
Photo taken from Hyundai Heavy Industries' website.

 The Options Submitted by Hyundai Heavy Industries:

During the Submission and Opening of Bid Envelopes (SOBE) for the Frigate Acquisition on 17 March 2016, only two bidders were declared to be able to proceed with the acquisition process. Among them was Hyundai Heavy Industries (HHI), which was declared the 2nd lowest bidder after Garden Reach Shipbuilders and Engineers (GRSE) of India. HHI  submitted 2 options for the Air/Surface Search Radar Systems: The Thales Nederland NS100 series AESA radar system, and the Airbus TRS-3D series radar system.

While other defense pages condemn MaxDefense, saying that our posts and information are half lies and innuendos, long-time MaxDefense readers and community members know that those accusations are false made by biased groups with vested interests in criticizing MaxDefense. The photo below was cropped from the actual Makers List submitted by HHI and included in the FAP's Contract signed last October 24, 2016. It clearly shows that HHI did offer 2 options for the ASSR. MaxDefense believes that no other defense page

The above shows the options submitted by HHI for the Air/Surface Search Radar (ASSR), which are the TNL (Thales Nederland) NS100 and the Airbus TRS-3D. Confirmation was made to MaxDefense that the specific versions being offered were the NS106 and the TRS-3D Baseline D. It also shows that HHI did offer 2 options for the CMS, although there is only 1 option for the Navigation Radar. MaxDefense decided to blur the other items for now and focus more on the ASSR.
Photo cropped from the FAP Contract's Annex F.

MaxDefense was lucky enough to be among the few who got access to the actual submissions made by GRSE and HHI, which allowed us to discuss them thoroughly through the years fro 2016 until the present.

Thales Nederland NS106 is a derivative of the newly developed but already successful NS100 series of AESA naval radars, and was said to be the actual model HHI is offering from the series. It takes improved performance over the older Thales Smart-S Mk. 2 radar, and uses Active Electronically Scanned Array (AESA) technology which is the latest technology in radar systems due to its ability to control beamed radio waves without the need to move the antenna, or require moving parts for the antenna.

The NS106 is a smaller version of the NS100, designed specifically for use on smaller warships from Offshore Patrol Vessels to small frigates. Its latest user is the Republic of Singapore Navy's Independence-class Littoral Missions Vessels.

The Thales Nederland NS100 series, which includes the NS106, uses AESA technology, and is among the latest naval radars in the market today. Despite being new, it is already in service with different navies.
Photo taken from Thales Nederland's website.

The latest user of the Thales Nederland NS100 (NS106) 3D AESA Radar is the Republic of Singapore Navy, installing them on the new Independence-class Littoral Missions Vessels. It would be noted that Singapore is among the most stringent in defense procurement, making sure that they get the best military technology to compensate for their lack of manpower.
Photo taken from Singapore's Ministry of Defence.

Meanwhile the Airbus (now Hensoldt) TRS-3D radar is in the global radar market for almost 15 years now, and is a proven product in use by several navies. It is actual a direct competitor of the Thales Smart-S Mk. 2, and uses the older pencil-beam technology, which is already being replaced in the market by the AESA technology. The TRS-3D is now marketed by the German company Hensoldt, which originated from Airbus' electronics business unit. The TRS-3D's latest user includes the US Coast Guard's Legend-class National Security Cutter.

MaxDefense received confirmation that the actual variant being offered by HHI is the current Baseline D variant, the same variant used by the USCG Legend-class NSC.

The latest version of Hensoldt's TRS-3D, the TRS-3D Baseline D, is being used by the US Coast Guard's Legend-class National Security Cutters. The Baseline D is said to be the one being offered by HHI to the PN, being the variant being produced by Hensoldt.
Credits to source of photo.

Philippine Navy's Technical Specifications versus the Radar's Specifications:

Now we compare if the two radars comply with the technical specifications for the Frigate Acquisition Program, based on publicly-available information.

Spec #1. Instrumented Range - should be at least 100 nautical miles (185 kilometres) for air targets and 40 nautical miles (74 kilometres) for surface targets.

Based on Thales Nederland's own product data sheet found in their website, the NS100 has a Maximum Instrumented Range of 280 kilometres, and a Maximum Range of 80 kilometres for surface targets. These are way beyond the 185 kilometres (air search) and 74 kilometres (surface search) required as per technical specs. 

And based on Hensoldt's own product data sheet also found in their website, the TRS-3D has a Maximum Instrumented Range of 200 kilometers, also beyond the requirement provided by the technical specs.

Based on this simple requirement, both the NS100 and TRS-3D comply with the technical specifications.

But based on information not released to the public by radar manufacturers, the TRS-3D has deficiencies due to the older technology it uses. 

It appears that the TRS-3D only has the capacity to meet this requirement is the 6s mode, which is an update time of every 6 seconds. The TRS-3D has a corresponding update time between 1 to 6 seconds (6s, 3.5s, 3s and 1s) with the 6s only meeting the maximum range requirements. This is due to the use of older Pencil-beam technology which requires the operator to choose from different search modes or patterns during operation. Example, there is a different mode and performance values when the radar is required to do horizon search against sea-skimming targets, and in conducting target acquisition, and in conducting volume search. In short, there is a compromise whenever the operator requires to use a different mode of operation while using the TRS-3D.

This is where an AESA-technology radar shows its value and better performance, as AESA radars do not require such compromise as it can perform all modes simultaneously. Meaning, it can do volume search, target acquisition, and horizon search on sea-skimming targets all at the same time.

Since the technical specifications does not indicate this requirement, the TRS-3D would actually be compliant with the PN's specs, although it is apparent here that the NS100 (and NS106) performs way better due to use of superior technology.

Spec #2. Tracking Capacity - should be at least 750 tracks for air and surface tracks.

Based on the same sources, the Thales Nederland NS100 has an air/surface track load of up to 1,000 tracks at a maximum, while Hensoldt TRS-3D only a maximum tracking capacity of more than 400 targets.

Given that manufacturers do not fully disclose the real maximum capabilities of their products, MaxDefense can assume it could be +5% to +10% more than the posted values. This gives the TRS-3D a theoretical maximum tracking capability at 440 to 450 targets.

Despite the use of a 10% allowance, it shows here than the Hensoldt TRS-3D does not meet the technical specifications for the frigates, while Thales Nederland NS100 can track twice more than the its competitor, and easily surpass the technical specifications by 25% more, thus the NS100 meets the technical specs easily.

Here alone, it is easy to say that Hensoldt TRS-3D should be disqualified from being used as the ASSR for the Philippine Navy's future frigates for failing to meet a technical specification requirement.

Spec #3. Detection Range - minimum of 200 meters up to a maximum of instrumented range 

Still based on the same sources as the other specs, the Thales Nederland NS100 has a minimum range of 15 meters, and a maximum range of 280 kilometres. Meaning, the NS100 exceeds the required minimum range, and also exceeds the required maximum range.

Meanwhile, the Hensoldt TRS-3D has a minimum range of 200 meters, which meets the requirement, while having a maximum range of 200 kilometers. Thus, the TRS-3D meets both the minimum and maximum range required by the technical specifications.

This is very important especially in law enforcement duties, since the radar is capable of detecting small boats very close to the frigate. While 200 meters is visible to the eye, it could be different during the night when darkness could work well for the approaching boat if their intention is unfavourable for the frigate. 

Spec #4. Azimuth Coverage - 360 Degrees

Based on both the product specification data sheets of both radar systems, the Thales Nederland NS100 and Hensoldt TRS-3D are both compliant with an azimuth coverage of 360 degrees.

Spec #5. Transmitter - Solid State

Both the Thales Nederland NS100 and Hensoldt TRS-3D uses Solid State transmitter technology, thus both are compliant with the solid state requirements.

Solid State transmitter technology is the latest in radar technology, replacing the Magnetron-based technology that has been used since the 1940s.
Photo taken from Toshiba's website.

Spec #6. Detection of sea skimming missiles at a minimum altitude of 10 feet to allow fire control resources sufficient time to lock-on and engage

This requirement is something that were not indicated in the product data sheets available online for both products. Thus requiring MaxDefense to use information that are not available to the public.

MaxDefense won't be too specific on the actual minimum altitude range that both radars can detect sea-skimming missiles due to obvious reasons. But MaxDefense confirms that both the NS100 and TRS-3D can detect a sea-skimming missile at a minimum altitude of 10 feet above the sea surface.

This requirement is important as most anti-ship missiles fly towards the ship by flying as close to the sea surface as possible. Between 15 to 10 feet above sea level is actually a typical elevation used by many anti-ship missiles when sea-skimming.

Modern anti-ship missiles usually approach targeted ships at very low altitude, usually less than 20 feet from the sea surface.
Photo taken from Lockheed Martin's website.

But this again would be something where superior technology creates a difference. The TRS-3D can do detection of sea-skimming targets only in the 1s mode with a maximum detection range of 11.3 nautical miles (20.9 kilometers). Meaning, if the radar is being used at other modes (3s, 3.5s or 6s), the TRS-3D cannot detect sea-skimming targets.

Meanwhile, the AESA technology of the NS100 allows it to operate in all aspects without the need to change modes of operation to do sea-skimming detection and volume search, thus the NS100 can detect sea-skimming targets at all times.

These performance figures are very important in today's battlefield to allow the ship's crews to react faster from threats, considering that anti-ship missiles are now travelling faster than ever.


Based on the technical specifications, it appears that Thales Nederland NS100 meets all the requirements, and even exceeded them with ease. 

Meanwhile, while Hensoldt TRS-3D met certain requirements, it failed to meet Specification #2, thus it automatically means that the TRS-3D does not meet the technical specifications of the project.

It would have been better if HHI offered the Hensoldt's newer and more capable ASSR, the TRS-4D AESA naval radar, which, after MaxDefense's own assessment versus the technical specifications of the project, complies with all requirements. TRS-4D is actually the direct competitor of the NS100, and uses the same technology and evenly matches in every aspect of capability and technology. Too bad HHI prefer to go cheap rather than fair.

Now, since based on the arguments pointed out by the Department of National Defense and the current leadership of the Philippine Navy is that Hyundai Heavy Industries will be the one who has the sole right to choose the subsystems for the frigate, MaxDefense believes that HHI will definitely use the Hensoldt TRS-3D radar for the frigates.

Not only is the TRS-3D cheaper by almost US$400,000 per unit compared to the NS106, but TRS-3D is compatible with the Hanwha Systems Naval Shield ICMS, this is due to the TRS-3D being in the market for almost 2 decades now, whereas the NS106 is not compatible yet due to NS106 being a newer product that has never been matched together with the Naval Shield and is not in service with the Republic of Korea Navy.

This is the bottom part of HHI's Makers List which is attached to the contract and signed by HHI and PN TWG Legal Officer Maj. Dayao. While it says that HHI has the sole right for the final selection for subsystems, the equipment shall fulfil the owner's requirements in building specifications and other design & build aspects. Since TRS-3D does not meet certain technical specification requirements, legally it should not be used for the frigate. But is NS100/NS106 compatible with Hanwha Naval Shield ICMS?
Photo cropped from HHI's Makers List as attached to the FAP contract.

But all parties, the PN TIAC and PMT, the DND and DND-Defense Acquisition Office, and HHI should remember that the clause also says "as long as equipment/sensor shall fulfill the owner's requirements in building specifications and other design & build aspects". So if HHI insists in using the Hensoldt TRS-3D, they are breaching the Technical Specifications, and in effect, breaching the contract of the project.

With the PN's TIAC already signed last 23 March 2018 according to our sources from the DND and the PN, its only a matter of time when a formal document will be made signifying the final equipment fit-out of the frigates. And MaxDefense would be there to cover that.



  1. For me HHI offered TRS-3D because not only it compatible with NSICMS,it is cheap so that the extra money that our government pay to them from the previous offer NS-106,they want to grab it for corruption. I hope DND and PN follow the original specifications and not allowing HHI to choose the subsystems.Sir max how about the sonar,iff,ESM, and the TDL are you discuss it soon?

  2. According to reports, HHI is losing billions in profit due to the ban imposed on it. I am not surprised they would pull this on us. They are desperate to stay afloat. I am not even sure they can complete the frigates before they declare bankruptcy.

  3. Heard HHI is losing billions after being banned by the Korean Government. What happens if they go bankrupt before they finish the ships?

  4. Cheers Sir Max! Thank you for this informative article provided to all people like myself who is concerned with the modernization program of the Armed Forces of the Philippines. A bit off topic Sir Max from the above article but still related to the FAP of the PN, I would just like to ask ,( to the community, sorry if this was ask previously but I still hope someone can enlighten me on this) why did the DND/PN choose the FAP program instead of prioritizing first to have OPVs ? Yes OPV capabilities are not equal to that of a frigate, but wouldn't it be more practical on the part of PN to immediately get OPVs as direct replacement for all the WW2 era ships to have a more capable naval vessels to be used in patrolling our EEZ? To give meaning to my query, here are some limited facts that I can think of in the practicality of getting OPVs. First is quantity. I'm not familiar with naval vessel cost but I believe OPV cost will be lower than a frigate so more ships can be procured and used. Second is comparable but limited offensive capabilities like a frigate. I'm looking at Singapore Independence class LMV and Brunei's Darussalam OPVs as the best example of capable OPV's that can have limited ASuW, AAW and may also have ASW if PN will look at the bigger OPV of Lurssen which is a sister ship of Darussalam OPV's where hangars are provided where the AW159 helicopters of PN can be deployed with. Third is the multi purpose capabilities of OPV’s as opposed to the main purpose of “offensive capabilities” of a Frigate. Just by checking all the naval shipyard websites as well as the previous ships that I have mentioned for comparison, they can be used not only to provide EEZ patrol and protection but as well as MOOTW (HADR is a must!) This is just my 2 cents and hopefully Sir Max and the community can enlighten me on this matter. Thank you again and God bless us all!

  5. In this case that partially the government and HHI will going to have a steel cutting on the said project this month and the Pohang class donation is also a good respectively.

  6. Any information regarding the final design and its component to be installed.......

  7. Sir Max, How does TRS-3D compares with Sea Giraffe intended for DP frigs?

  8. I read sometime ago that the EASA radar has one handicap compared to phased array radar like the Hensoldt offering to our frigates. Though phased array radar signal emanates from one single source and transmitted by a single transmitter, the heating problem of the system is controlled unlike in the EASA radar where it uses many transmitter/receiver modules and function at the same time, thermal heat problem is greater. Their resolve to this issue is to disable the whole system for sometime to cool down before resuming its function. While in its cooling stage, the radar information needed should come from other source like AWAC, aircraft, etc. These many subsystems makes also the EASA more costly by some millions of dollars than the phased array radar. Some radar makers on one hand are thinking to combine the EASA tech and phased array radar but the cost will be a great hindrance in marketing.
    If the issues of EASA radar are true, phased array radar from Hensoldt is practical in our frigates and allocate the price difference in ammunitions; in any way we cant face a single multiple air/surface targets combat engagement since our frigate are configured for 4 surface missiles and 4 air missiles.

  9. VLS provision should have been minimum 16 cells...where all navies in the world are sporting latest missile defenses, 8 cells is laughable IMO

  10. I think when the corvettes arrive with much more sophisticated sensors, they will be grouped together with this frigates in order to compensate for its shortcomings.


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