Ground Passive Radar - the end of Stealth ?

[Kunal Biswas]

- Latest radar technology uses reflections from radio and television stations

- Expanded mission spectrum in civil air traffic control and military aerial reconnaissance

Cassidian, the defence and security division of EADS, has developed what is known as "passive radar" that can locate even difficult-to-detect flying objects such as stealth aircraft and that itself is practically undetectable. In contrast to conventional radar, passive radar doesn't emit any radiation, but instead analyses radiation reflections from other emitters, such as radio and television stations, to detect objects.

"The principle of passive radar has been known for a long time," says Elmar Compans, Head of Sensors & Electronic Warfare at Cassidian. "However, we have now integrated the latest capabilities of digital receiver and signal processing technology to significantly enhance range and detection accuracy by monitoring various emitters at the same time."

With its passive radar, Cassidian is focussing on the requirements of civil and military airspace control which until now could not or not sufficiently be met using active emitting radar. In civil application, passive radar makes cost-effective air traffic control possible without any additional emissions and without making demands on transmission frequencies in short supply. In military applications, the system enables large-area surveillance using networked receivers, while offering the decisive operational advantage that passive radar cannot be located by hostile forces. The particular characteristics of the omnipresent radio signals used for operation enable detection of even objects that are difficult to detect, such as stealth aircraft or stealth ships. A further advantage of the new technology is its increased detection capacity in areas of radar shadow such as mountainous terrain and its capability to locate extremely slow and low flying objects.

A demonstration system has already been delivered to the German Federal Office of Defense Technology and Procurement (BWB). Cassidian's passive radar can be used for mobile deployment in a vehicle of the size of a commercial van and thus can be moved very quickly and with little logistical effort. After successful testing, including at Stuttgart Airport, the plan is to set up a production prototype system and to carry out evaluation programmes by both Cassidian and the customer by the end of the year.


Passive radar from CASSIDIAN remains invisible - Cassidian.com
---------------------------------------------------------------------------------------


Things have been around since the 80s, like the Tamara (pic below)

 

[Kunal Biswas]

Re: Cassidian Passive Radar: The end of stealth..

Place them around places when any radar emit any radiation these system together can detect pinpoint location of the Aircraft even if the Aircraft radar is switched off..

This kind of tech is very effective against those fighter which have angled surface, Stealth fighter which use radar absorbing materiel may have chance to escape..

In future, Stealth tech may not be of angled surface fighters but more of radiation absorbing tech..

 

[Kunal Biswas]

Similar Systems :

Topaz Kolchuga / Kolchuga M Emitter Locating System

The Topaz Kolchuga is a long range direction finding Electronic Support Measures receiver system, which if networked can provide the functions of an Emitter Locating System using triangulation and DTOA techniques. The design is claimed to have been nominated for a State Science and Engineering Prize. It was developed during the 1990s by a consortium including the Special Radio Device Design Bureau public holding company, the Topaz holding company, the Donetsk National Technical University, the Ukrspetsexport state company, and the Investment and Technologies Company.

Claimed band coverage extents from 130 MHz (VHF) up to the X/Ku-bands. Claimed sensitivity is -110dBW to - 155 dBW. Track capability is claimed to be 32 concurrent targets.

The Kolchuga is also claimed to combine DF techniques with DTOA techniques. The latter will be limited in angular extent to targets which fall into the mainlobes of the respective antenna components for the band in question.

The sale of four systems to the PRC has been reported. There is ongoing speculation that the system has been supplied to Iran but no validation to date.

 

[Kunal Biswas]

Re: Cassidian Passive Radar: The end of stealth..

Tesla-Pardubice KRTP-81/81M Ramona / Soft Ball Emitter Locating System

The Ramona was deployed first in 1979, as a replacement for the PRP-1 Kopac DTOA ELS which was developed during the 1960s, and retired in the late 1990s. It was superceded in production by the mobile KRTP-86 Tamara. The Ramona system was built in a semimobile configuration, either on a ground based platform or 25 metre tethered lattice mast. The mast mounted variant weighed in total 160 tonnes, and was carried by no less than thirteen Tatra 138/148 10 tonne 6x6 trucks. The spherical radome housed the receivers and datalink transceivers required to operate three or more stations. Deployment of the system on site takes 12 hours.

Band coverage was 1 to 8 GHz, with the primary application in locating and tracking airborne IFF/SSR transponders and TACAN installations. Twenty targets could be tracked concurrently.

The Ramona was regarded to be complicated and troublesome to deploy, factors which strongly influenced the design of the subsequent Tamara. Seventeen baseline KRTP-81 systems were built, 14 exported to the Soviet Union, 1 to the DDR, 1 to Syria, and 1 deployed by the CSLA. Fifteen improved KRTP-81M systems were built, the Soviets buying 10, Syria 3 and the CSLA deploying 2 systems.

 

[Kunal Biswas]

Re: Cassidian Passive Radar: The end of stealth..

Tesla-Pardubice KRTP-86/91 Tamara / Trash Can Emitter Locating Systems

The KRTP-84 Tamara was an evolution of the Ramona, designed with high mobility and rapid deployment as a priority. Testing of prototypes began in 1983, followed by state trials and certification in 1987. A single system is carried by eight Tatra 815 8x8 trucks (Equivalent to the MAZ-543), comprising three RS-AJ/M receiver systems with telescoping masts, and a mix of RS-KB hardware containers, RS-KM signal processing equipment container and a ZZP-5 command van. The mast mounted RS-AJ/M can elevate to 8.5, 12.5 or 25 metres AGL and can operate at wind strengths below 60 knots, with a structural limit of 100 knots. The cylindrical antenna radome houses the receiver equipment and datalink transceivers for networking the stations. In a typical deployment the receivers are stationed at distances of 5 to 20 NMI.

Cited band coverage is 820 MHz to 18 GHz. Design objectives included the tracking of the F-15 at 200 NMI and F-16 at 215 NMI, with the cited range limit being 240 NMI and limited primarily by the curvature of the earth. Russian sources claim that 72 targets can be tracked within a 100° angular sector, these including emitting JTIDS/Link-16 terminals. In 1991 the baseline KRTP-86 was superceded in production by improved the KRTP-91 Tamara-M.

Russian sources claim that 23 Tamara and Tamara M systems were built before production switched to the Vera series. Of these, the USSR/Russia acquired 15 Tamara systems and 4 Tamara-M systems, the CSLA 4 Tamara M systems, the GDR NVA one Tamara system, with claims that the US acquired two systems via Oman.

 

[Kunal Biswas]

Re: Cassidian Passive Radar: The end of stealth..

ERA KRTP-96M4 - BORAP Emitter Locating System

The KRTP-96 series are a follow-on design to the KRTP-91 Tamara series, using a much larger antenna package, and achieving IOC with Czech Army units in 1999. The system has a DF capability and is typically deployed in pairs, providing coverage over a 120 degree angular sector. Frequency coverage is L-Band throught to Ku-band. The system can be deployed in ~1 hr.

 

[Kunal Biswas]

Re: Cassidian Passive Radar: The end of stealth..

ERA Vera E Emitter Locating Systems

The post Cold War Vera systems are improved derivatives of the Tamara, and have not proven particularly successful in the market, in a large part due to the fact that the clients most interested in the product are not part of the Western alliance. China was granted export licences in 2004 for six Vera-E systems, which were revoked after pressure was brought to bear by the US State Department. There are reports that Malaysia, Vietnam, Pakistan and Egypt were interested in acquiring the system. The Czech Army has acquired one system, the US DoD one system, and the Estonians one system.

 

[Kunal Biswas]

Re: Cassidian Passive Radar: The end of stealth..

RAMET / VTÚO SDD Stanice Dalekého Dosahu (Long Range ESM Station)

The SDD long range ESM system was introduced in 2001 as a replacement for the obsolescent Soviet SDR-2 system. Deployed in pairs, this monopulse system is credited with a range of up to 330 NMI with coverage between 0.8 and 8 GHz, effective against pulse and CW emitters. The antennas use steerable feeds. The system is deployed on TATRA 4x4 ARMAX truck with a KSSK container and towed antenna suite.

 

[Kunal Biswas]

Re: Cassidian Passive Radar: The end of stealth..

85V6 Vega / Orion ELINT System

 

[Kunal Biswas]

Re: Cassidian Passive Radar: The end of stealth..

Lantan/Almaz-Antey Valeria E ELINT and Emitter Locating System

Russian sources have reported the development of the Valeria E which appears to be Russian designed and built replacement for the Czechoslovak KRTP-86/91 Tamara series of emitter locating systems. To date no imagery of the antenna system and vehicles has been published.The system is intended to detect, track and identify airborne emitters, including radars and support jamming aircraft, from VHF through to the Ku/Ka bands. A cylindral wideband phased array antenna is employed.

The Valeria E comprises at least four networked subsystems, one central processing and C3 cabin, and three antenna/receiver units. While each system provides a circular coverage footprint within which range, azimuth and elevation can be measured, it is intended that multiple systems be deployed with overlapping coverage. Elevated terrain is recommended to improve coverage. The networked components are typically sited at 10 to 35 km apart.

 

[Kunal Biswas]

Re: Cassidian Passive Radar: The end of stealth..

Chinese CETC DWL002 Passive Detection System

"DWL002 Passive Detection System, also called as passive radar, is mainly used in air-defense or seashore monitoring to perform the detection to perform the detection and location to airborne, shipborne or landbased emitters in complex electromagnetic environment and display the target flight path in real time. The system can also operate together with active detection system to form a mutual supplementary surveillance network.

Typical configuration of DVL002 Passive Detection 'system is composed of three reconnaissance stations. One of them serves as master station and the other two as slave stations. The system can be expandable to four station configuration with perfect performance of full spatial coverage and altitude information of air target. Each station is carried by an individual vehicle.

Main Functions:
* Realtime & Accurate Location and Tracking
* Signal Analysis and Identification
* Long Range Detection and Early Warning

Main Features:
* Passive
* Real Time
* Very Good Mobility

DWL002 Passive Detection System is a three station configuration (expandable to four station configuration). Each station. including antenna and power generator. is housed and carried by one vehicle. which ensures the good mobility of the system

* Remote Control
* Advanced techniques

Long base line time difference of arrival (TDOA) location technique combined with AOA: Wideband digitized receiver technique; Multilevel correlation processing technique with good flight track processing result: Automatic set up. Chassis leveling techniques and automatic north calibration technique to ensure fast deployment and flexible operation."

 

[Kunal Biswas]

Though about Cassidian passive radar System :

The particular characteristics of the omnipresent radio signals used for operation enable detection of even objects that are difficult to detect, such as stealth aircraft or stealth ships. A further advantage of the new technology is its increased detection capacity in areas of radar shadow such as mountainous terrain and its capability to locate extremely slow and low flying objects.

Its like it a Jar ( Environment ) full of water ( Radio signals ) and fish ( Stealth fighter ) swim which displace water ( Sensor catch unknown object in the environment ), In this system there is very rare chance of escape..

 

[ersakthivel]

Re: Cassidian Passive Radar: The end of stealth..

Place them around places when any radar emit any radiation these system together can detect pinpoint location of the Aircraft even if the Aircraft radar is switched off..

This kind of tech is very effective against those fighter which have angled surface, Stealth fighter which use radar absorbing materiel may have chance to escape..

In future, Stealth tech may not be of angled surface fighters but more of radiation absorbing tech..

The RAM coat can only absorb a minute amount of radiation. If full absorption of Radar waves is achieved the surface heat will increase manifold and then the stealth aircraft will have a very high amount of heat signature. Because absorbed radio waves will produce tremendous amount of heat, since the exposure to radar waves is continuing activity through out the flight time.

 

[Armand2REP]

Similar Systems :

Topaz Kolchuga / Kolchuga M Emitter Locating System

Kolchuga isn't really a similar system as it uses triangulation to pick up aircraft emissions. The EADS passive radar uses already existing radio emitters aside from the source. It is the exact opposite process.

 

[ersakthivel]

And also in future all combat aircrafts will carry these passive receivers. SO any 5th gen aircraft that deflects radar waves in multiple directions won't be stealth as its deflections in many directions can be picked up by multiple receivers and triangulating algorithms can be written to identify it's position accurately.it is no great leap of technology. and if the source of radar emissions are multiplied and receivers are also multiplied means this method is beyond the jamming capacity of any ew craft.

 

[sob]

Kunal, how will this work in the Himalyas where due to zero population there are hardly any signals of TV, FM or cellular signals.

This would work very well over populated areas but over such remote areas or over vast expanses of the sea, how will it work. Could you shed some light on it.

 

[sob]

Since mid 90s the E-3 Sentry Awacs have been fitted with Passive Radars as part of it's ESM upgrades.

 

[Kunal Biswas]

Kolchuga isn't really a similar system as it uses triangulation to pick up aircraft emissions. The EADS passive radar uses already existing radio emitters aside from the source. It is the exact opposite process.

Though both are considered in category of passive radar systems..

EADS is a further step in this evolutions..

 

[p2prada]

Kunal, how will this work in the Himalyas where due to zero population there are hardly any signals of TV, FM or cellular signals.

TV Signals, FM, Cellular signals are all HF and VHF frequencies. There are radars capable of transmitting such frequencies over long distances, namely the Nebo family of radars from Russia.

NNIIRT Nebo SVU / RLM-M Nebo M / Assessing Russia's First Mobile VHF AESAs

It is theoretically possible for a receiver to look out for incoming cellphone waves that have bounced off from aircraft. But, the cellphone information can come from any direction and the information carried will give you nothing about what you detected. For eg: You may have picked up birds or insects and not aircraft which are designed to have the RCS the size of birds or insects.

You would rather just use a Nebo type radar system for the same purpose. The only difference is Russia/China have invested in VHF technologies while other countries have not.

Other than that ground based passive systems are the same as what is carried by AWACS and ELINT/SIGINT aircraft. Monitoring enemy voice communications is SIGINT. These concepts have existed for many decades now and there are many platforms carrying Signals intelligence receivers. A RWR is also a passive "anti-stealth" system.

ELINT and Radar systems have existed in tandem for decades now. The fact is adding this term "anti-stealth" to a ground based passive receiver is simply used to build up hype around a system that nobody buys in large numbers. It does the same as it has been doing since decades, nothing more. Meaning this system is heavily dependent on the "enemy" giving away it's position due to faults in emitters like radars and bad design. Also the fact that the stealth aircraft should be "emitting" at the time which it almost never does.

F-22 works similarly. It keeps it's radar turned off and only receives signals. If there is an enemy transmitting, the RWR picks up the signals and tries identifying the threat. Once the emitter is identified, depending on the threat it turns on the radar and transmits in the LPI mode to pick up the threat for engagement. If the receiver reads the threat as a civilian passenger aircraft or any other aircraft which is not a military threat, the radar is not used. So, the F-22 is consistently working as a passive system too and can read the same cellphone and TV signals.

4th gen aircraft work in the same way, though at varying degrees of sophistication, when AWACS cover is available.

 

[Kunal Biswas]

Kunal, how will this work in the Himalyas where due to zero population there are hardly any signals of TV, FM or cellular signals.

This would work very well over populated areas but over such remote areas or over vast expanses of the sea, how will it work. Could you shed some light on it.

There are two ways :

1. Such System works with other systems where radars which release radiation in different bands and these Receivers as sensors keep track of the environment..

2. Aircraft own radiation from its many systems like IFF, Communication and radar can give receivers the location..