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{{Article Infobox2
#REDIRECT [[Galileo Public Regulated Service (PRS)]]
|Category=GALILEO
|Title={{PAGENAME}}
|Authors=GMV
|Level=Basic
|YearOfPublication=2011
|Logo=GMV
}}
 
The [[GALILEO General Introduction|GALILEO]]  System will be an independent, global, European-controlled, satellite-based navigation system and will provide a number of guaranteed services to users equipped with Galileo-compatible receivers. The [[GALILEO Public Regulated Service]] (PRS) provides position and timing restricted to government-authorised users, for sensitive applications which require a high level of service continuity. It will be encrypted and designed to be more robust, with anti-jamming mechanisms and reliable problem detection. This service is intended for security and strategic infrastructure (e.g. energy, telecommunications and finance).<ref name="Mid-term review">[http://ec.europa.eu/enterprise/newsroom/cf/_getdocument.cfm?doc_id=6321 Mid-term review of the European satellite radio navigation programmes]</ref> <ref name="Regulation"> [http://eur-lex.europa.eu/JOHtml.do?uri=OJ:L:2008:196:SOM:en:HTML Regulation (EC) No 683/2008 of the European Parliament and of the Council of 9 July 2008 on the further implementation of the European satellite navigation programmes (EGNOS and Galileo).]</ref>
 
PRS is one of the important features of Galileo that adds value
compared to other satellite navigation systems. The access to PRS will be
limited to authorised governmental bodies.
 
==Purpose==
[[File:egnos_2.png‎|300px|Galileo Open Service|thumb]]
 
Galileo is a civil system that also includes a robust and access-controlled service for government-authorised applications. The Public Regulated Service (PRS) will be used by groups such as police, coast-guards and customs. Civil institutions will control the access to the encrypted PRS. Access by region or user group will follow the security policy rules applicable in Europe.
The PRS is operational at all times and in all circumstances, including during periods of crisis. A major PRS driver is the robustness of its signal, which protects it against jamming and spoofing.<ref name="ESA_GALILEO">[http://www.esa.int/esaNA/galileo.html ESA Galileo web page]</ref>
 
[[File:Galileo Frequencies.gif‎|200px|Galileo Signal Frequencies|left|thumb]]
 
==Performance and features==
 
The [[GALILEO Signal Structure|Galileo Public Regulated Service]] is realized by two signals, one in the 1575.42 MHz band and the other in the 1278.75 MHz band. These signals are encrypted, allowing the implementation of an access control scheme.<ref name="ESA_GALILEO"/>.<ref>[http://ec.europa.eu/enterprise/policies/satnav/galileo/files/galileo-os-sis-icd-issue1-revision1_en.pdf Galileo OS SIS ICD Issue 1 Revision 1 September 2010e]</ref>
 
The PRS will provide a higher level of protection against the threats to Galileo Signals in Space than is available for the Open Services (OS, CS and SoL) through the use of appropriate interference mitigation technologies.
The need for the Public Regulated Service (PRS) results from the analysis of threats to the Galileo system and the identification of infrastructure applications where disruption to the Signal in Space (SiS) by economic terrorists, malcontents, subversives or hostile agencies could result in damaging reductions in national security, law enforcement, safety or economic activity within a significant
geographic area.
 
The objective of the PRS is to improve the probability of continuous availability of the SIS, in the presence of interfering threats, to those users with such a need.
 
The Public Regulated Service access will be controlled by the authorities to be defined at European level, through the encryption of the signals and the appropriate key distribution. The performance objectives in terms of position accuracy and availability are described in next table: <ref name="GALHLD"> [http://ec.europa.eu/dgs/energy_transport/galileo/doc/galileo_hld_v3_23_09_02.pdf Galileo Mission High Level Definition], v3, September 2002.</ref>
 
{| class="wikitable" align="center"
|+align="bottom" |''Service Performances for Galileo Open Service''
|-
! rowspan="2" |
! colspan="2"| Galileo  Open Service (positioning & timing)
|- align="center"
!  Single Frequency (SF) 
! Dual Frequency (DF)
|- align="center"
! Coverage
| colspan="2"|          Global
|- align="center"
!  rowspan="2" | Accuracy (95%)
|  Horizontal: 15 m
|  Horizontal: 4m
|- align="center"
| Vertical: 35 m
| Vertical: 8m
|- align="center"
! Availability
| colspan="2"|          99.8 %
|- align="center"
! Timing Accuracy wrt UTC/TAI
| colspan="2"| 30 ns
|- align="center"
! Ionospheric Correction
| Based on SF Model
| Based on DF Measurements
|- align="center"
! Integrity
| colspan="2"|          No
|}
 
To know more information about Performances of each Galileo Service see the article [[GALILEO Performances|Galileo Performances]].
 
==Implementation and PRS Aplications==
The Open Service signals are separated in frequency to permit the correction of errors induced by ionospheric effects by differentiation of the ranging measurements made at each frequency. Each navigation frequency will include two ranging code signals (in-phase and quadrature). Data are added to one of the ranging codes while the other “pilot” ranging code is data-less for more precise
and robust navigation measurements.
 
During the Initial Operational Capability (IOC) phase, the GALILEO open service, the search and rescue service and the PRS will be provided. At this stage, however, accuracy and availability will not yet have reached their optimum levels.<ref name="Mid-term review">[http://ec.europa.eu/enterprise/newsroom/cf/_getdocument.cfm?doc_id=6321 Mid-term review of the European satellite radio navigation programmes]</ref>
 
PRS applications will be used by emergency services, critical transportation, energy or telecom and defence purposes: even if Galileo is the first civilian GNSS in the world, nothing prevents the Member States to use it for military purposes. In this context, the PRS can have important impacts on the Europe's Common Foreign and Security Policy (CFSP) and on the European Security and Defence Policy (ESDP).<ref name="EC GAL web">[http://ec.europa.eu/enterprise/policies/satnav/galileo/index_en.htm EC Galileo website]</ref>
Typical applications include:<ref name="GALHLD"/>
# Trans-European level
#* Law Enforcement (EUROPOL, Customs, European Anti-Fraud Office - OLAF);
#* Security Services (Maritime Safety Agency) or Emergency Services (peace keeping forces or humanitarian interventions);
# Member States levels
#* Law enforcement;
#* Customs;
#* Intelligence Services.
 
==Notes==
<references group="footnotes"/>
==References==
<references/>
 
[[Category:GALILEO]]

Latest revision as of 12:43, 25 April 2011