Transcript The ‘Eurofix versus Loran Data Channel’ Debate

New Loran-C Receiver Performance
Levels for Extended Range Eurofix and
Kinematic Applications
G.W.A. Offermans, A.W.S. Helwig,
R. Kellenbach, W.J. Pelgrum, D. van Willigen
Reelektronika b.v. / Reeuwijk / The Netherlands
ILA 31
Washington D.C., USA, 27-30 October 2002
Overview
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Reelektronika’s new receiver LORADD
Functional description of LORADD
Measurement results
Extended range Eurofix
Polar flights
Conclusions
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LORADD Receiver Design
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Development was done within EC Gloria project
(Gnss and LOran-c for Road and raIl Applications)
Design of a (potentially) low-cost Loran-C receiver
Receiver is part of a tightly-coupled integrated
receiver with GPS
Use of H-field antennas for urban applications
Complex H-field antenna design by Reelektronika
Currently, fourth generation H-field antenna
design underway
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Receiver characteristics
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DSP-type receiver allows
implementation of new algorithms
All-in-View Rx processes all signals that
can be received
Very fast acquisition
Cross-rate interference rejection
Continuous wave interference rejection
Dual H-field antenna requires
processing of two data streams
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Third generation prototype
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Functional Diagram
GLORIA Integrated Navigation Receiver
H-field antennas
(Reelektronika)
GPS antenna
(NovAtel)
GPS
Receiver
Loran-C Receiver
LORADD
LORADD
GPS receiver
(NovAtel)
(Reelektronika)
Integration
Software
Position Out
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LORADD Functional Description
Signal
conditioning
Dual H-field
Raw
antenna
samples
Data
demod
Data
decoding
Data
output
A/D converter
Cross-rate
Station
filtering
RF front-end tracking
RF signals
DSP
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Station
acquisition
RF/IF signals
Position
calculation
DSP
Chain
selection
samples
Position
output
(pseudo) ranges,
position
Cross-rate in Europe
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Cross-rate in Europe, cnt’d
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Interference Mitigation
Interference
source
Mitigation method
Performance
Continuous wave
Detect and notch
++
Atmospherics,
low amplitudes
Integration
+
Atmospherics,
large amplitudes
Detect and drop
++
Cross-rate
Detect and drop
-+
Cross-rate
Filtering
++
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Measurement Campaign LORADD
Reelektronika test vehicle
GPS
Antenna
LORADD
Antenna
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Measurement Campaign LORADD
Play movie
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Measurement Results LORADD
Paris, in Carpark, F, 4-9-2002
2 floors below ground
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Measurement Results LORADD
Paris, in Carpark, F, 4-9-2002
Accuracy:
72 m (95%) !
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Measurement Results LORADD
Reeuwijk, NL, 28-8-2002
Smallaxis:
axis:
Accuracy:
Long
5
74
(95%)
85mm(95%)
Loran-C
Geometry in
Netherlands is
BAD!
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Potential
Loran-C
positioning
accuracy
Measurement Results LORADD
Munchen, D, 12-6-2002
Accuracy:
33 m (95%)
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Measurement Results LORADD
Paris, Eiffel tower, F, 5-9-2002
Accuracy:
14 m (95%)
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Distribution of EGNOS over Loran-C
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EGNOS TRAN program by ESA
Phase II:
broadcast of EGNOS derived Eurofix
messages (RTCM SC104 compatible)
Phase III:
broadcast of EGNOS regional area
messages using new Eurofix data format
Phase II installed at Sylt,
Phase III expected early next year
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Tracking a station at 2,000 km
9007 Boe / H-field Antenna / 1,920 km
1
0.8
0.6
0.4
0.2
0
1
17
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33
49
65
81
97
113
129
2,000 km Range Eurofix
9007X (Bø): Lost Eurofix Message Probability vs SNR
100
5000
90
4500
80
4000
70
3500
# Messages
60
3000
Lost Message
Probability
50
2500
40
2000
30
1500
20
1000
10
500
0
0
26
24
22
20
18
SNR (dB)
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16
14
12
# of Messages Received per 0.5 dB
Lost Eurofix Message Probability (%)
Ankeveen (NL), September 13-14, 2002
2,000 km Range Benefits
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Polar flights offer reduced flight time, saves
fuel and, relieves Atlantic Ocean slot crowding
In Polar Region no Geostationary SBAS or
communication available
Currently, communication solved by HF radio
Navigation based on GPS and IRS, no
external integrity
GPS integrity can be solved by extended
range Eurofix through WAAS/EGNOS
rebroadcast
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Polar
Routes
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Restricted Russian polar
routes: Polar 1 to 4
Preferred random routing
in Canada
2005: 9000+ commercial
polar flights estimated
Savings:
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Flying time: 2+ hrs
Costs: US$ 16 k/flight
Time slots Atlantic
‘Polar Routes Feasibility
Study’, Nav Canada and
FAAR, October 2000
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Polar Region Eurofix Stations?
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Russia
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USA & Canada
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Inta / 4970M & 5960Z / 1,200 kW
Norilsk / 5960M / 1,200 kW
Taimylar Peninsula / 5960X / 1,200 kW
Pankratyev Island (Nova Zembla) / 4970M & 5960X / 250 kW
Port Clarence / 7960Z & 9990Y / 1,000 kW
Tok / 7960M / 560 kW
Fox Harbor / 5930Z & 7270X / 800 kW
Europe
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Jan Mayen / 7001X & 9007W / 250 kW
Berlevåg / 7001Y / 250 kW
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Polar
Eurofix
7960M
560 kW
9990Y+7960Z
1,000 kW
9990Y+7960Z
1,000 kW
5960X
1,200 kW
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Estimated Eurofix
coverage
Larger ground
wave attenuation
Less atmospheric
noise
Less Cross-rate
Less CWI (continuous
wave interference)
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4970X+5960Y
250 kW
7270X+5930Z
800 kW
7001X+9007W
250 kW
7001Y
250 kW
4970M+5960Z
1,200 kW
Conclusions
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New Loran-C receiver technology caused
breakthrough in performance
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Eurofix is up and running, and standardised
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Fast acquisition times (10+ stations in 10 seconds)
Accurate 5-sec independent TOA measurements
2001 – ITU-R Recommendation M.589-3
2002 – RTCM SC-104 V2.3
New services
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EGNOS data broadcast through Eurofix network
UTC dissemination
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Conclusions
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Reelektronika developed a prototype
Loran-C/Eurofix receiver within the
Gloria project (LORADD)
NELS is funding the development of a
miniaturized integrated Loran/GPS
receiver (based on LORADD)
Phase III of EGNOS TRAN project is
about to start. EGNOS regional area
messages will be broadcast over Eurofix
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