RHINOS “Railway High Integrity Navigation Overlay System”

RHINOS Workshop 21st June 2017

Performance Analysis Activity

R. Capua (Sogei)

Objectives

• Simulation and Analysis of High Precision and High Integrity positioning in the Rail Scenario for GNSS PVT only (No ERTMS)

• Simulation of SIS and Augmentation System Faults

• Design and Integration of a Performance Analysis Tool

• Performance Analysis

• Virtual Test Bed:

• Injection of Faults into raw data recorded by a GNSS Receiver installed On-Board and into Augmentation data

• Simulated Data

• Analysis performed through the RadioLabs GNSS3inSim

Participants

• Sogei: TAAN Network Control Centre developments, 2-Tiers FDE, Fault Generations

• RadioLabs: Performance Analysis Simulation developments

• University of Notthingam: Environmental Faults Simulation

• Ansaldo STS: Rail Sector requirements and review

• University of Pardubice: Fault Scenarios and Requirements Analysis

Performance Analysis Tools

• RadioLabs: Train Integrity Simulator (Virgilio)

• Sogei: 2-Tiers Sardinia ERSAT-EAV network raw data and Control Centre, SIS and LA fault generation, GNSS SDR and Spoofer

• University of Notthingam: Spirent Simulator

Extended Fault Tree

ETCS Core Hazard

THR=2e-9 / 1 hr / train

Odometry

Hazard

Radio subsystem

Hazard

Communication among RBC, TALS GNSS OBU

Virtual Balise Detection Hazard

THRVB = 1e-9/ 1 hr

Balise / Loop Hazard

cross talk (balise insertion)

Track-side GNSS SIS/ augmentation

failure and RBC contribution

&

Ʃ 0.5e-9/ hr 0.5e-9/ hr

Environmental anomalies

and OBU function failures On-board

Ʃ Ʃ

GNSS SIS/

augmen. failure

RBC contribution to VB detection/ reporting failure

Track database excessive error

OBU contribution to VB detection failure

Excessive error due to multipath

Excessive error due to spoofing, EMI

Ʃ

Augmen. syst . failure (PE>PL)

SV faults Iono + tropo effects

Multipath, spoofing

Function B must be based on different technology than ARAIM to achieve physical, functional and process independence.

2e-10/ hr 0.25e-10/ hr 2e-10/ hr 0.25e-10/ hr

Function A: ARAIM

Function B

0.25e-10/ hr

Level 1

Level 2

Level 3

Level 4

Level 5

Level 6

2e-10/ hr

~1e-6/ hr

< 1e-10/ 1 hr 1e-11/ hr

4.5e-10/ hr

4.5e-10/ hr

THRVB of 1e-9/ hr was derived

according to SUBSET-088 under

assumption that independent

diagnosis during Start of Mission

(SOM) is available (track circuits,

axle counters) and thus hazard due

to cross talk effect (detection of wrong

virtual balise) ban be mitigated.

Train position: UNKNOWN

at the beginning of SOM

5e-10/ hr 5e-10/ hr

1e-10/ hr 2e-10/ hr 2e-10/ hr 0.25e-10/ hr

LDS Start of Mission on parallel

tracks is required (AL=3 m)

Local Augmentation Architecture

Example of Extended Scenarios Definition

Simulation Architecture

ERSAT-EAV

ERSAT-EAV Reference Station Network Architecture

GRDNet Control Centre

Final Review Meeting

ERSAT-EAV

Guspini

Municipality

Cagliari

Tax Police

Sanluri

“Giovanni XIII” Primary School

Vallermosa

Municipality

Vallermosa

Municipality

ERSAT-EAV Reference Station Network

Virgilio Simulator

RS

TALS OBU

GNSS RX

GNSS RX RINEX

RINEXGNSS

RX

GNSS RX RINEX

RINEX

RS

RS

Timing

Wall Clock Time

SimulatedTime

Track DB

SyntheticObservations

Generator

Track & Motion Model

Generator

External tools

Logging

GNSS 3InSim

GRDNet RS and SIS Integrity Monitoring

• Reference Stations and SIS FDE through Real Time 2-Tiers (EDAS+Local Augmentation) algorithm (from ERSAT-EAV)

Sogei GNSS SDR Spoofing Simulation

• GPS/EGNOS Single-Frequency SDR

• Totally Software Signal Processing

• No FPGA, No Low Cost Receivers

• Front-End design & development

• Programming:

• C++, GPU, Parallel Programming

• C/N0 monitoring Anti-Spoofing

• Real-time SDR running on Desktops, Notebooks and Tablets

• RTK through standard NTRIP/RTCM connection to a GNSS Network

Extended Local Augmentation Fault-Tree

Signal

Fault Cases

• SIS Fault

• Ephemeris/Clock Faults

• Augmentation Faults

• RS Interferences

• Local Effects:

• Multipath

• Trees

• Interferences

• Communication Losses

• Multiple Failures

Scenario n Single Fault Multiple Fault

Constellation x

Sats x

Communication x

SBAS

LAAS x

Human x

……

Scenario 2 Single Fault Multiple Fault

Constellation x

Sats x

Communication x

SBAS

LAAS x

Human x

……

Scenario 1 Single Fault Multiple Faults

Constellation x

Sats x

Communication x

SBAS x

TAAN x

Multipath x

Spoofing x

…

RHINOS “Railway High Integrity Navigation Overlay System”

Performance Analysis Results and Execution

Performance Analysis Test Scenarios • Full Supervision/Nominal Operation

• Nominal Operation (Clear-Sky)

• SIS Failure simulation, Evil Waveform

• Ephemeris fault simulation

• Satellite Clock Error simulation

Open Sky Simulation

%of epoch for System Unanailable 0.068135

% of epochs for System in Normal Operation 99.93186

% of epochs for System is in MI/HMI 0

Evil Waveform Evil Waveform simulation: Fault–Free PRN compared to Digital and Analogic distortion on PRN code (generated through the Qascom Simulator)

Evil Waveform

%of epoch for System Unanailable 0.141044

% of epochs for System in Normal Operation 99.85896

% of epochs for System is in MI/HMI 0

Ephemeris Fault generation

Clock Fault Generation

Ephemeris Fault

%of epoch for System Unanailable 0.070522

% of epochs for System in Normal Operation 99.92948

% of epochs for System is in MI/HMI 0

Ephemeris Fault generated through GNSS SDR on satellite 12

Multiple Failures

One satellite faulted every 240 s 3 GPS + 1 Galileo remaining at the end

%of epoch for System Unanailable 0.085179

% of epochs for System in Normal Operation 99.91482

% of epochs for System is in MI/HMI 0

Presence of Spoofing

No Railway RAIM) PVT associated with HMI would be detected and discharged by ERTMS & Railway RAIM

%of epoch for System Unanailable 13.05832

% of epochs for System in Normal Operation 85.06401

% of epochs for System is in MI/HMI 1.877667

Spoofing signal generated by a Qascom simulator

Start of Mission Performance Analysis • Start of Mission SoM (Simulated Data)

• Urban Area - Severe Shadowing

• Urban area - Severe Multipath

• Interferences (Spoofing)

• RTK positioning (start from position unknown)

Start of Mission – RTK Positioning (Floating)

RTK Floating Ambiguities Solution (Weak Multipath)

Start of Mission – RTK Positioning (Fixed)

%of epoch for System Unanailable 0

% of epochs for System in Normal Operation 100

% of epochs for System is in MI/HMI

Fixed Ambiguities Solution (Weak Multipath)

Reference Stations Fault Monitoring

• Effective tools integrated for GNSS Local Augmentation and SIS FDE Performance Analysis (ERSAT-EAV)

RS 6 CTNB RIMS RS 5 GUSP RS 4 SANL RS 3 VALL RS 2 CAGR RS 1 VILL

CAGR RS Fault

RS FDE

Conclusions

• Effective tools integrated for GNSS Local Augmentation and SIS FDE Performance Analysis

• Simulation Scenarios defined through GNSS data recorded from an On-Board GNSS receiver and simulated GNSS data

• Rail Operations Environmental Scenarios tested for the GNSS positioning only with several Faults (Ephemeris and Clock, Evil Waveforms, Interferences, Multiple Failures). No ERTMS functional blocks and Railway RAIM included

• 2-Tiers Algorithm is able to perform FDE for Single and Multiple Satellite Faults and Reference Stations Failures

• RTK Positioning Integrity Performances Evaluated in float and fixed ambiguity states

• Next step: Multipath impacts analysis

ION GNSS+ 2016

Thanks for the attention