View source for VERA passive sensor

{{Short description|Radar detection system}}
{{Infobox Radar 
|name        = VERA
|image       = ILA Berlin 2012 PD 042.JPG
|caption     = VERA next generation receiver unit
---- 
|country     = {{CZE}} 
|introdate   = 
|number      = 
|type        = Ground-based emitter tracking system
|frequency   = 1–18 [[GHz]]
|range       = ~450 km nominal
|altitude    =
|diameter    = 
|azimuth     = 120–360° depending on mode
|elevation   = 
|precision   = 
|power       = 
|other names={{flagicon|Vietnam}} V-ELINT18 (resemblance)
}}

The '''VERA''' [[passive radar|passive surveillance ESM system]]<ref name=":0" /> (known as ''Věra'' in [[Czech language|Czech]]) 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. The manufacturer is {{ill|ERA a.s.|cz}}, based in [[Pardubice]].<ref name=":0">{{Cite web |title=VERA-NG |url=https://www.era.aero/military-security/vera-ng |access-date=2023-08-17 |website=ERA a.s. |language=en}}</ref>

==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 passive sensor|Kopáč]] which could track 6 targets.

This was followed by KRTP-81 [[Ramona passive sensor|Ramona]] ([[NATO reporting name]] Soft Ball) in 1979, which could track 20 targets, and KRTP-86 [[Tamara passive sensor|Tamara]] (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 (Czechoslovak company)|Tesla]], which collapsed after the [[Velvet Revolution]] (1989). Lead engineers from the former Tesla company formed the ERA Company in [[Pardubice]] which produces the current generation VERA family of sensors.

;Timeline
* October 30, 2006 - [[Rannoch Corp.|Rannoch Corporation]] announced the acquisition of ERA a.s. located in Pardubice Czech Republic.<ref>{{cite web |url=http://www.erabeyondradar.com/press-releases/era-aquisition.html |title=Era - Beyond Radar - Rannoch Corporation Acquires ERA to Create the Global Leader |website=www.erabeyondradar.com |url-status=dead |archive-url=https://web.archive.org/web/20070928093610/http://www.erabeyondradar.com/press-releases/era-aquisition.html |archive-date=2007-09-28}} </ref>
* February 6, 2007 – Rannoch Corporation has officially changed its name to Era Corporation.<ref>{{cite web |url=http://www.erabeyondradar.com/press-releases/era-corporation.html |title=Era - Beyond Radar - Rannoch Changes Company Name to Era Corporation |website=www.erabeyondradar.com |url-status=dead |archive-url=https://web.archive.org/web/20070928093603/http://www.erabeyondradar.com/press-releases/era-corporation.html |archive-date=2007-09-28}} </ref>
* July 2008 - Era Corporation was acquired by [[SRA International]].
* November 22, 2011 - ERA Pardubice was bought by Czech arms and aircraft trading company [[Omnipol]].<ref>[https://archive.today/20130118164109/http://www.businessweek.com/ap/financialnews/D9R5RKF03.htm] </ref>

==Mode of operation==
[[File:VERA SM passive sensor.jpg|thumb|Receiver of VERA S/M]]
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]].

The height of a target with an [[secondary surveillance radar|SSR]] Mode C or Mode S [[transponder]] 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]] [[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]]. 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&nbsp;km from the central site, providing a reasonable compromise of coverage and accuracy.

The system is generally [[Line-of-sight propagation|line-of-sight]] limited, with a nominal range of 450&nbsp;km, the normal [[radio horizon]]. Detection of targets is within a sector of approximately 120 degrees, although [[identification friend or foe|IFF]] and [[secondary surveillance radar|SSR]] targets are detected using a dedicated [[omnidirectional antenna]], 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]] and typically exploit secondary surveillance radar ([[secondary surveillance radar|SSR]]) [[transponders]], identify friend or foe ([[identification friend or foe|IFF]]) transponders, airborne radars, [[weather radar]]s, tactical air navigation ([[TACAN]]) transponders, distance measurement equipment ([[distance measuring equipment|DME]]) beacons, digital communications signals and pulsed [[radar jamming|jamming]] signals.

==Versions==
{{unreferenced section|date=November 2022}}
[[File:ILA Berlin 2012 PD 040.JPG|thumb|Model of VERA-NG]]
VERA is supplied in a number of versions. VERA-AP is the civilian long-range [[air traffic control]] (ATC) version, which only exploits civilian SSR transponders at 1030 and 1090&nbsp;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]] system known as BORAP.

Czech company ERA in cooperation with the German SMAG introduced a brand new mobile antenna mast for its system VERA-NG. The prototype is due to be finished in Q1/2017 and be ready for first deliveries at the end of this year.

==Exports==
{{refimprove section|date=November 2022}}
Public domain literature claim VERA-E systems have been exported to [[Malaysia]], [[Estonia]], [[Pakistan]] and the [[United States]].<ref>{{Cite web |last=Kominek |first=J |date=October 2004 |title=Czech government clears sale of VERA-E to US |url=https://www.researchgate.net/publication/294251621 |access-date= |website=[[ResearchGate]]}}</ref> Newspaper reports also claimed that in January 2004 the Czech defence sales company, [[Omnipol]], received licence to sell six systems to [[China]]. 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 (České Budějovice District)|Planá]] near [[České Budějovice]].

==Users==
{{refimprove section|date=November 2022}}
[[File:VERA passive sensor Users.png|thumb|Map with VERA passive sensor users in blue]]
* {{CZE}}
* {{flagicon|Estonia}} [[Estonia]]
* {{flagicon|Indonesia}} [[Indonesia]]
* {{Flagicon|Malaysia}} [[Malaysia]]
* {{Flag|Moldova}}: 1 VERA-NG on order 2024.
* {{flagicon|Pakistan}} [[Pakistan]]
* {{flagicon|Slovakia}} [[Slovakia]]
* {{Flag|Ukraine}}: 4 VERA-NG were purchased by Netherlands for Ukraine in 2023.<ref>{{Cite web |last=Defensie |first=Ministerie van |date=2023-06-14 |title=Training van Oekraïense F-16-vliegers start in de komende maanden - Nieuwsbericht - Defensie.nl |url=https://www.defensie.nl/actueel/nieuws/2023/06/14/training-van-oekraiense-f-16-vliegers-start-in-de-komende-maanden |access-date=2023-06-14 |website=www.defensie.nl |language=nl-NL}}</ref>
* {{flagicon|USA}} [[United States]]
* {{flagicon|Vietnam}} [[Vietnam]]: VERA-NG systems were imported and entered operation since 2015.<ref>{{Cite web |last=VCCorp.vn |date=2015-01-18 |title=Mắt thần Vera-NG - Khắc tinh của máy bay tàng hình |url=https://soha.vn/news-20150118123641516.htm |access-date=2023-11-20 |website=soha.vn |language=vi}}</ref>
** Local variant '''V-ELINT18''' ''Electronic Intelligence System'' ({{Langx|vi|Hệ thống Trinh sát điện tử thông minh|lit=Smart [[Signals intelligence|Electronic reconnaissance]] system}})<ref>{{Cite web |title=Electronic Intelligence System |url=https://viettelhightech.vn/en/category-detail/electronic-intelligence-system |access-date=2023-11-20 |website=Viettel High Tech |publisher=[[Viettel Group]] |language=en}}</ref><ref>{{Cite web |title=Hệ thống Trinh sát điện tử thông minh |url=https://viettelhightech.vn/category-detail/electronic-intelligence-system |access-date=2023-11-20 |website=Viettel High Tech |publisher=[[Viettel]] |language=vi}}</ref> was developed and produced by [[Viettel]]. An unidentified number of Viettel-made systems that look visually identical to the imported VERA have been acquired and commissioned by the [[General Staff of the Vietnam People's Army|General Staff of the Vietnam People's Army Department of Electronic Warfare]] since 2021. The V-ELINT18 is claimed as having equivalent functions & performance to the VERA-NG.<ref>{{Cite web |title=Electronic Intelligence System |url=https://viettelhightech.vn/en/category-detail/electronic-intelligence-system |access-date=2023-04-21 |website=Viettel High Tech |language=en}}</ref>

==See also==
General topic
*[[ELINT]]/[[electronic support measures|ESM]]

Similar systems
*[[Kolchuga passive sensor|Kolchuga]] – a similar system developed in the Soviet Union, manufactured in Ukraine
*[[Kopáč passive sensor|Kopáč]] – the first generation Czech ESM TDOA system
*[[Ramona passive sensor|Ramona]] – the second generation Czech ESM TDOA system
*[[Tamara passive sensor|Tamara]] – the third generation Czech ESM TDOA system
*DPET – Deployable Passive ESM Tracker, Czech system based on upgraded technological core of Věra NG
*BORAP – a contemporary Czech ESM triangulation system
*[[YKLC-20 passive sensor|YLC-20]] - a Chinese development of Czech Tamara first revealed in 2006

==References==
<references />

==External links==
*[http://www.era.cz ERA Company]
*[http://www.icao.int/Meetings/AMC/MA/2005/ADSB_SITF4/sp06.pdf PDF company presentation]
*[http://www.pasivnisystemy.cz Czech ESM/EW unit site]

[[Category:Radiofrequency receivers]]