EGNOS Performance Improvements Using Monitoring Stations in Romania

Vlad-Cosmin Vasile1, Georgiana Magu2, Romeo Cosnita2,

Corina Nafornita2, Alexandru Isar2, Monica Borda1

1 Technical University of Cluj-Napoca

2 Politehnica University of Timisoara

INTRODUCTION

• EGNOS (European Geostationary Navigation Overlay Service)

– the European satellite-based augmentation system (SBAS)

– it complements the satellite navigation system provided by the US Global Positioning System (GPS)

• Romania is a good candidate for system performance monitoring at the border of EGNOS service area.

• This paper describes the simulations of EGNOS performances improvements when using Ranging & Integrity Monitoring Stations (RIMS) sites in Romania

PERFORMANCE ASSESSMENT STRATEGY• The overall availability: percentage of time when the protection levels are below

the alarms (HPL<HAL) & (VPL<VAL)

• The scenarios considered that use RIMS sites are evaluated based on protection

levels (XPL) but also NSE and DOP

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Performance measure and AcronymPerformance measures used

Description from SBAS Simulator V1 Types

Dilution of Precision DOP or

Geometric Dilution of Precision GDOP

A GPS term used in geomatics engineering to

describe the geometric strength of satellite

configuration on GPS accuracy.

Two types of simulation are available: availability and

statistics.

• HDOP horizontal

• VDOP vertical GDOP geometric

• PDOP positional

• TDOP time

Navigation System Error NSE NSE computes navigation system errors.• HNSE horizontal

• VNSE vertical

Protection levels XPL XPL computes protection levels.

• HPL horizontal

• VPL vertical

• XPL horizontal and vertical: computed using

HPL&VPL data as described below.

OTHER SETTINGS

OTHER SETTINGS

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SIMULATION SCENARIOS

Location/CodeCoordinates

Longitude (°) Latitude (°)

Timisoara/TIM 21.21 45.75

Bucharest/BUC 26.12 44.43

Cluj-Napoca/CLU 23.64 46.77

Iasi/IAS 27.60 47.17

Scenario ID RIMS NetworkNumber of RIMS sites added on top of EGNOS RIMS

network baseline

Scenario RIMS

Extension type

SCN_1 REF+ TIMISOARA 1

Single

RIMS sites

SCN_2 REF+ BUCHAREST 1

SCN_3 REF+ CLUJ-NAPOCA 1

SCN_4 REF+ IASI 1

SCN_5 REF+ TIMISOARA+ BUCHAREST+ CLUJ-NAPOCA+ IASI 4

Multiple

RIMS sites

SCN_6 REF+ TIMISOARA+ BUCHAREST+ CLUJ-NAPOCA 3

SCN_7 REF+ BUCHAREST+ IASI 2

SCN_8 REF+ CLUJ-NAPOCA+ IASI 2

SCN_9 REF+ TIMISOARA+ IASI 2

SCN_1REFERENCE + TIMISOARA

SCN_2REFERENCE + BUCHAREST

SCN_3REFERENCE + CLUJ-NAPOCA

SCN_4REFERENCE + IAŞI

SINGLE RIMS SITE SCENARIOS

Scenario Id

Rank of interest for single site scenarios

SCN_1 vs. SCN_2 vs. SCN_3 vs. SCN_4 vs. Rank of interest

SCN_1TIM

- SCN_1 SCN_1 SCN_1 4/4

SCN_2BUC

SCN_2 - SCN_2 SCN_2 2/4

SCN_3CLU

SCN_3 SCN_3 - SCN_3 3/4

SCN_4IAS

SCN_4 SCN_4 SCN_4 - 1/4

SCN_5: REFERENCE+TIMIŞOARA+ BUCHAREST+CLUJ-NAPOCA+IAŞI

SCN_6: REFERENCE + TIMIŞOARA+BUCHAREST

SCN_7: REFERENCE + BUCHAREST+IAŞI

SCN_8: REFERENCE + CLUJ-NAPOCA+IAŞI

SCN_9: REFERENCE + TIMIŞOARA+IAŞI

MULTIPLE RIMS SITE SCENARIOS

Scenario Id

Rank of interest for multiple sites scenarios

RIMS sites added

SCN_5 vs. SCN_6 vs. SCN_7 vs. SCN_8 vs. SCN_9 vs.Rank of interest for

availability coverage

Rank of interest for number of RIMS vs

availability coverage

SCN_5TIM, BUC, CLU, IAS

- SCN_5 SCN_5 SCN_5 SCN_5 1/5 5/5

SCN_6 TIM, BUC, CLU SCN_6 - SCN_6 SCN_6 SCN_6 4/5 4/5

SCN_7 BUC, IAS SCN_7 SCN_7 - SCN_7 SCN_7 2/5 1/5

SCN_8 CLU, IAS SCN_8 SCN_8 SCN_8 - SCN_8 3/5 2/5

SCN_9 TIM, IAS SCN_9 SCN_9 SCN_9 SCN_9 - 5/5 3/5

CONCLUSIONS

• We have studied the theoretical extension of coverage for the EGNOS performances when using monitoring stations located in Romania.

• We created scenarios with added RIMS sites and we studied the extension of EGNOS coverage in these cases.

• In the case of single RIMS site scenarios, we found out the best two locations are Iasi and Bucharest.

• With respect to the multiple RIMS sites scenarios case, the best coverage was provided by the scenario that includes all four RIMS locations.

• However, by looking at the efficiency coverage versus number of RIMS deployed, it was seen that the scenario with Iasi and Bucharest is the one with the best trade-off.

Thank you!