VERA passive sensor
Encyclopedia
VERA -VERA passive radiolocator (in Czech
Czech language
Czech is a West Slavic language with about 12 million native speakers; it is the majority language in the Czech Republic and spoken by Czechs worldwide. The language was known as Bohemian in English until the late 19th century...

 known as Věra) is an electronic support measures (ESM) system that uses measurements of time difference of arrival (TDOA) of pulses at three or four sites to accurately detect and track airborne emitters.

Mode of operation

The deployed system typically comprises a central site (containing the signal processing equipment and an ESM receiver) and two or three side sites containing only an ESM receiver. The side sites relay the signals received to the central site over a point-to-point microwave link. The central site uses the known propagation delay from the side sites to estimate the TDOA of the pulses at each site. The TDOA of a pulse between one side site and the central site locates the target on a hyperboloid. A second side site provides a second TDOA and hence a second hyperboloid. The intersection of these two hyperboloids places the target on a line, providing a 2D measurement of the target's location (no height). A third side-site provides a third hyperboloid, which, when intersected with the line provided by the other two side sites, provides a full 3D location of the target. This process is known as multilateration
Multilateration
Multilateration is a navigation technique based on the measurement of the difference in distance to two or more stations at known locations that broadcast signals at known times. Unlike measurements of absolute distance or angle, measuring the difference in distance results in an infinite number of...

. The height of a target with an SSR
Secondary surveillance radar
Secondary surveillance radar is a radar system used in air traffic control , that not only detects and measures the position of aircraft i.e. range and bearing, but also requests additional information from the aircraft itself such as its identity and altitude...

 Mode C or Mode S transponder
Transponder
In telecommunication, the term transponder has the following meanings:...

 can also be provided by decoding the Mode C or Mode S response directly, which is the normal mode of operation for the civilian VERA-AP system.

System accuracy

System accuracy is typically better than a microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...

 surveillance radar, and is a function of the deployment geometry, the inherent timing accuracy of the central site, the bandwidth of the pulse being detected and the signal-to-noise ratio
Signal-to-noise ratio
Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. It is defined as the ratio of signal power to the noise power. A ratio higher than 1:1 indicates more signal than noise...

. Wider separations of the side sites from the central site provide better accuracies – but at the expense of a reduced area of common coverage. Typically side sites are deployed 15-40 km from the central site, providing a reasonable compromise of coverage and accuracy.

The system is generally line-of-sight
Line-of-sight propagation
Line-of-sight propagation refers to electro-magnetic radiation or acoustic wave propagation. Electromagnetic transmission includes light emissions traveling in a straight line...

 limited, with a nominal range of 450 km, the normal radio horizon. Detection of targets is within a sector of approximately 120 degrees, although IFF
Identification friend or foe
In telecommunications, identification, friend or foe is an identification system designed for command and control. It is a system that enables military and national interrogation systems to identify aircraft, vehicles, or forces as friendly and to determine their bearing and range from the...

 and SSR
Secondary surveillance radar
Secondary surveillance radar is a radar system used in air traffic control , that not only detects and measures the position of aircraft i.e. range and bearing, but also requests additional information from the aircraft itself such as its identity and altitude...

 targets are detected using a dedicated omnidirectional antenna
Omnidirectional antenna
In radio communication, an omnidirectional antenna is an antenna which radiates radio wave power uniformly in all directions in one plane, with the radiated power decreasing with elevation angle above or below the plane, dropping to zero on the antenna's axis. This radiation pattern is often...

, and hence may be seen over 360 degrees. Up to 200 targets can be automatically tracked simultaneously, with an output rate adjustable from 1 to 5 seconds.

Exploited emitters

The current generation sensor can only detect and track pulsed emissions, due to the requirement to measure the time of arrival of pulses. The receivers operate in the frequency range of 1-18 GHz
GHZ
GHZ or GHz may refer to:# Gigahertz .# Greenberger-Horne-Zeilinger state — a quantum entanglement of three particles.# Galactic Habitable Zone — the region of a galaxy that is favorable to the formation of life....

 and typically exploit secondary surveillance radar (SSR
Secondary surveillance radar
Secondary surveillance radar is a radar system used in air traffic control , that not only detects and measures the position of aircraft i.e. range and bearing, but also requests additional information from the aircraft itself such as its identity and altitude...

) transponders, identify friend or foe (IFF
Identification friend or foe
In telecommunications, identification, friend or foe is an identification system designed for command and control. It is a system that enables military and national interrogation systems to identify aircraft, vehicles, or forces as friendly and to determine their bearing and range from the...

) transponders, airborne radars, weather radar
Weather radar
Weather radar, also called weather surveillance radar and Doppler weather radar, is a type of radar used to locate precipitation, calculate its motion, estimate its type . Modern weather radars are mostly pulse-Doppler radars, capable of detecting the motion of rain droplets in addition to the...

s, tactical air navigation (TACAN) transponders, distance measurement equipment (DME
Distance Measuring Equipment
Distance measuring equipment is a transponder-based radio navigation technology that measures distance by timing the propagation delay of VHF or UHF radio signals....

) beacons, digital communications signals and pulsed jamming signals.

Versions

VERA is supplied in a number of versions. VERA-AP is the civilian long-range air traffic control
Air traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...

 (ATC) version, which only exploits civilian SSR transponders at 1030 and 1090 MHz. VERA-E is the export version of the military ESM version of the system, also referred to as the VERA-S/M in its national mobile version. In addition, the shorter range VERA-P3D system is marketed for highly accurate monitoring of transponder-equipped ground vehicle movement at airports. The manufacturers also market an ESM triangulation
Triangulation
In trigonometry and geometry, triangulation is the process of determining the location of a point by measuring angles to it from known points at either end of a fixed baseline, rather than measuring distances to the point directly...

 system known as BORAP
BORAP passive sensor
BORAP is an ELINT/ESM system designed and developed by the company in the Czech Republic, manufacturers of the VERA system.BORAP is designed for the detection, identification, location and tracking of air, ground and naval targets using an advanced wideband interferometric direction finding...

.

Exports

Open literature sources claim VERA-E systems have been exported to Estonia
Estonia
Estonia , officially the Republic of Estonia , is a state in the Baltic region of Northern Europe. It is bordered to the north by the Gulf of Finland, to the west by the Baltic Sea, to the south by Latvia , and to the east by Lake Peipsi and the Russian Federation . Across the Baltic Sea lies...

, Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

 and the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. Newspaper reports also claimed that in January 2004 the Czech defence sales company, Omnipol
Omnipol
Omnipol is a company based in Prague, Czech Republic, specialising in the trading of defence and aerospace equipment.-International sales:Omnipol acts as the intermediary in government-to-government sales of defence equipment, meeting the needs of air and ground forces in more than 60 countries...

, received licence to sell six systems to China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

. However, US government pressure on the Czech government resulted in the cancellation of this contract. Civil systems have been widely exported throughout Europe.

Within the Czech Republic, a mobile VERA-E unit is operated by the 53rd Passive Radiotechnical Reconnaissance System and Electronic Warfare Centre at Planá
Planá (Ceské Budejovice District)
Planá is a village in the South Bohemian Region of the Czech Republic. It has around 250 inhabitants.First written mention about the settlement is from year 1259...

 near České Budějovice
Ceské Budejovice
České Budějovice is a city in the Czech Republic. It is the largest city in the South Bohemian Region and is the political and commercial capital of the region and centre of the Roman Catholic Diocese of České Budějovice and of the University of South Bohemia and the Academy of Sciences...

.

History

VERA is the latest in a long history of Czech ESM TDOA systems. The first system developed by the Czech army in 1963 was known as PRP-1 Kopáč
Kopác passive sensor
Kopáč was an early electronic warfare support measures system developed in Czechoslovakia in the early 1960s that used measurements of time difference of arrival of pulses at three sites to accurately detect and track airborne emitters...

 which could track 6 targets. This was followed by KRTP-81 Ramona
Ramona passive sensor
Ramona was the second generation Czechoslovakian electronic support measures system that uses measurements of time difference of arrival of pulses at three or four sites to accurately detect and track airborne emitters by multilateration.-History:...

 (NATO reporting name
NATO reporting name
NATO reporting names are classified code names for military equipment of the Eastern Bloc...

 Soft Ball) in 1979, which could track 20 targets, and KRTP-86 Tamara
Tamara passive sensor
Tamara was the third generation Czechoslovak electronic support measures system that used measurements of time difference of arrival of pulses at three or four sites to accurately detect and track airborne emitters by multilateration. Tamara's serial numbers were KRTP-86 and KRTP-91 and it...

 (NATO reporting name Trash Can) in 1987, which could simultaneously track 23 radar targets and 48 IFF targets. These were widely exported to the former Soviet Union and beyond. These predecessors were manufactured by the state company Tesla
Tesla (company)
TESLA was a large, state-owned electrotechnical conglomerate in the former Czechoslovakia....

, which collapsed after the Velvet Revolution
Velvet Revolution
The Velvet Revolution or Gentle Revolution was a non-violent revolution in Czechoslovakia that took place from November 17 – December 29, 1989...

 (1989). Lead engineers from the former Tesla company formed the ERA Company in Pardubice
Pardubice
Pardubice is the capital city of the Pardubice Region and lies on the river Elbe, 65 miles east of Prague. Pardubice has an antique centre square and old town, with many restaurants that stay open until late in the evening. There is an old Tower and a recently renovated Castle...

 which produces the current generation VERA family of sensors.

October 30, 2006 - Rannoch Corporation announced the acquisition of ERA a.s. located in Pardubice Czech Republic.

February 6, 2007 – Rannoch Corporation has officially changed its name to Era Corporation.

July 2008 - Era Corporation was acquired by SRA International
SRA International
SRA International, Inc. is an information technology services and solutions consulting company incorporated as Systems Research and Applications Corporation in 1976 and beginning operations in 1978. Founded by Dr. Ernst Volgenau, it is headquartered in Fairfax, Virginia, and employs 7200 people...

.

November 22, 2011 - ERA Pardubice was bought by Czech arms and aircraft trading company Omnipol
Omnipol
Omnipol is a company based in Prague, Czech Republic, specialising in the trading of defence and aerospace equipment.-International sales:Omnipol acts as the intermediary in government-to-government sales of defence equipment, meeting the needs of air and ground forces in more than 60 countries...

.

See also

  • ELINT\ESM
  • Kolchuga
    Kolchuga passive sensor
    The Kolchuga passive sensor is an ESM system developed in Ukraine. Its detection range is limited by line-of-sight but may be up to for very high altitude, very powerful emitters...

     – a similar system developed in Ukraine
  • Kopáč
    Kopác passive sensor
    Kopáč was an early electronic warfare support measures system developed in Czechoslovakia in the early 1960s that used measurements of time difference of arrival of pulses at three sites to accurately detect and track airborne emitters...

     – the first generation Czech ESM TDOA system
  • Ramona
    Ramona passive sensor
    Ramona was the second generation Czechoslovakian electronic support measures system that uses measurements of time difference of arrival of pulses at three or four sites to accurately detect and track airborne emitters by multilateration.-History:...

     – the second generation Czech ESM TDOA system
  • Tamara
    Tamara passive sensor
    Tamara was the third generation Czechoslovak electronic support measures system that used measurements of time difference of arrival of pulses at three or four sites to accurately detect and track airborne emitters by multilateration. Tamara's serial numbers were KRTP-86 and KRTP-91 and it...

     – the third generation Czech ESM TDOA system
  • BORAP
    BORAP passive sensor
    BORAP is an ELINT/ESM system designed and developed by the company in the Czech Republic, manufacturers of the VERA system.BORAP is designed for the detection, identification, location and tracking of air, ground and naval targets using an advanced wideband interferometric direction finding...

     – a contemporary Czech ESM triangulation system
  • YLC-20 - a Chinese development of Czech Tamara first revealed in 2006

External links

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