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UPC
research group of Astronomy and Geomatics
EGNOS TUTORIAL
Research group of Astronomy and GEomatics
(gAGE/UPC)
Universitat Politècnica de Catalunya
e-mail: jaume@mat.upc.es
http://gage1.upc.es
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 1
UPC
research group of Astronomy and Geomatics Summary
• Part I: The EGNOS system
– Augmentation Systems
– EGNOS System Architecture
• Part II: Data Processing
– SBAS Differential Corrections and Integrity
– Performance
– Examples
• Part III: EGNOS and Civil Aviation
– Introduction to Civil Aviation Navigation
gAGE
– The EGNOS benefits
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 2
UPC
research group of Astronomy and Geomatics
PART I
The EGNOS System
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 3
UPC
What Augmentation is?
research group of Astronomy and Geomatics
• To enhance the performance of the current GNSS
with additional information to:
– Improve INTEGRITY via real-time monitoring
– Improve ACCURACY via differential corrections
– Improve AVAILABILITY and CONTINUITY
• Satellite Based Augmentation Systems (SBAS)
– E.g., WAAS, EGNOS, MSAS
• Ground Based Augmentation Systems (GBAS)
– E.g., LAAS
• Aircraft Based Augmentation (ABAS)
gAGE
– E.g., RAIM, Inertials, Baro Altimeter
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 4
UPC
Why Augmentation Systems?
research group of Astronomy and Geomatics
• Current GPS/GLONASS Navigation Systems
cannot met the Requirements for All Phases
of Flight:
– Accuracy
– Integrity
– Continuity
– Availability
• Marine and land users will also require
some sort of augmentation for improving
the GPS/ GLONASS performances.
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 5
UPC
research group of Astronomy and Geomatics WHY GNSS NEEDS AN AUGMENTATION ?
WHY GNSS NEEDS AN AUGMENTATION ?
GPS Only Civil Aviation
PERFORMANCE CATEGORY I
Requirements
H. 13 m V. 22m ACCURACY (95%) H 16.0 m V 4.0 m
99% (RAIM) AVAILABILITY 99% to 99.990%
2.10-7/ approach
? INTEGRITY Time to alarm 6 s
gAGE
? 10-5 / approach
CONTINUITY OF SERVICE (10-6 / 15 s)
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 6
Accuracy: Difference between the measured position at any given
UPC
research group of Astronomy and Geomatics
time to the actual or true position.
Even with S/A off a Vertical Accuracy< 4m 95% of time
cannot be and After S/A was switched
GPS Before achieved with standalone GPS. off
Colorado Springs, Colorado 2 May 2000
160
140 Horizontal Error (meters)
120 Vertical Error (meters)
100
80
Instantaneous Error (meters)
60
40
20
0
-20
-40
-60
-80 ANALYSIS NOTES
-100
-120 - Data taken from Overlook PAN Monitor Station,
equipped with Trimble SVeeSix Receiver
-140 - Single Frequency Civil Receiver
-160 - Four Satellite Position Solution at Surveyed Benchmark
gAGE
-180 - Data presented is raw, no smoothing or editing
-200
0 1 2 3 4 5 6 7 8 9 10
Time of Day (Hours UTC)
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 7
Integrity: Ability of a system to provide timely warnings to users or
UPC
research group of Astronomy and Geomatics
to shut itself down when it should not be used for navigation.
Standalone GPS and GLONAS Integrity is Not Guaranteed
GPS/GLONASS Satellites:
• Time to alarm is from minutes to hours
• No indication of quality of service
Health Messages:
• GPS up to 2 hours late
• GLONASS up to 16 hours late
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 8
UPC Continuity: Ability of a system to perform its function without
(unpredicted) interruptions during the intended operation.
research group of Astronomy and Geomatics
Availability: Ability of a system to perform its function at initiation of
intended operation. System availability is the percentage of time
that accuracy, integrity and continuity requirements are met.
Availability and Continuity Must meet requirements
• Continuity:
Less than 10-5 Chance of Aborting
a Procedure Once it is Initiated.
• Availability:
gAGE
>99% for every phase of flight (SARPS).
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 9
UPC
research group of Astronomy and Geomatics INTEGRITY
a th
ual p
Act
e
em h
st y t
NSE
Sy b
n ed
tio cat
ga di
vi In
Na th
Confidence bound
Pa
• Less than 10-7 probability of true
gAGE
Alert Limit error larger than confidence bound.
• Time to alarm 6 s
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 10
Strong Requirements for
UPC
research group of Astronomy and Geomatics
the safety in Civil Aviation
If fault is not declared after:
• Over bound the alarm threshold
• and alarm delay
ry
je ct o
Thence: l Tra
m ina Threshold alarm
Fault of Integrity Accident risk No
Alarm Delay
?
gAGE
• < 10-5 Chance of Aborting a
Procedure Once it is Initiated.
• Time to alarm 6 s
EGNOS Tutorial. Barcelona, February 2003 Hernández-Pajares M., Juan M., J. Sanz, X. Prats 11
UPC
SBAS and GBAS Navigation Modes
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 12
UPC
Aviation Signal-in-Space Performance Requirements
research group of Astronomy and Geomatics
Aviation Accuracy Accuracy Alert Alert Integrity Time Continuity Avail-
(H) 95% (V) 95% Limit (H) Limit (V) to alert ability
ENR 3.7 Km N/A 7400 m N/A 1-10-7/h 5 min. 1-10-4/h 0.99
(2.0 NM) 3700 m to to
1850 m 1-10-8/h 0.99999
TMA 0.74 Km N/A 1850 m N/A 1-10-7/h 15 s 1-10-4/h 0.999
(0.4 NM) to to
1-10-8/h 0.99999
NPA 220 m N/A N/A 1-10-7/h 10 s 1-10-4/h 0.99
(720 ft) 600 m to to
1-10-8/h 0.99999
APV-I 220 m 20 m 600 m 50 m 1-2x10-7 per 10 s 1-8x10-6 in 0.99
(720 ft) (66 ft) approach any 15 s to
0.99999
APV-II 16.0 m 8.0 m 40 m 20 m 1-2x10-7 per 6s 1-8x10-6 in 0.99
(52 ft) (26 ft) approach any 15 s to
0.99999
CAT-I 16.0 m 6.0 - 4.0 m 40 m 15 -10 m 1-2x10-7 per 6s 1-8x10-6 in 0.99
(52 ft) (20 to 13 ft) approach any 15 s to
0.99999
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 13
UPC
Maritime Signal-in-Space Performance Requirements
research group of Astronomy and Geomatics
Maritime Accuracy (H) Alert Limit (H) Time Integrity risk
95% to alert (per 3 hours)
Ocean 10m 25m 10sec 10-5
Costal 10m 25m 10 s 10-5
Port approach and 10m 10 s 10-5
restricted waters 25m
Port 1m 2.5m 10 s 10-5
Inland waterways 10m 25m 10 s 10-5
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 14
UPC
research group of Astronomy and Geomatics
GBAS Concept
• Most of the measurement errors are common:
clock, ephemeris, ionosphere and troposphere.
• A common correction valid for any receiver within the LADGPS
area is generated and broadcast.
gAGE
• The accuracy is limited by the spatial decorrelation of those
error sources (1m at 100Km).
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 15
Differential Correction Calculation
UPC
Broadcast Actual SV
SV Position Position
research group of Astronomy and Geomatics
Calculated Measured
PRref Pseudoranges PRuser
Range ρref
Corrections Differential Message Broadcast
REF Calculation PRC
Known Reference
Location USER
– The first receiver in a reference station can calculate these errors
knowing its exact location (corrections “PRC” calculated by the GBAS
ground station): PRC= PRref - ρref
– The second receiver (the user) will use these corrections to correct its
gAGE
own measurements and increase the accuracy of these
measurements: PRuser- PRC
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 16
Measured Pseudorange
UPC
Geometric Range Rec Sat.
Eph Iono Tropo Noise
User receiver Clock Clock
research group of Astronomy and Geomatics
Correlated Errors Uncorrelated
Rec Sat.
Eph Iono Tropo Noise
Clock Clock
PRC: Pseudo-Correction broadcasted
Geometric Range Rec
Noise Noise
User receiver Clock
Residual
gAGE
Corrected Pseudorange
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 17
UPC ERORS on the Signal
research group of Astronomy and Geomatics
• Space Segment Errors:
– Clock errors Common
– Ephemeris errors
Strong spatial
• Propagation Errors correlation
– Ionospheric delay
– Tropospheric delay Weak spatial
correlation
• Local Errors
– Multipath No spatial
gAGE
– Receiver noise correlation
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 18
LADGPS Ephemeris Correction Errors due to the
UPC
Geographic Separation
research group of Astronomy and Geomatics
True position
∆E ∆E’’~0
∆E’
Position from
broadcast ∆E: Satellite location error
ephemeris
Receiver A
gAGE
Receiver B
Reference Station
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 19
UPC
research group of Astronomy and Geomatics
http://www.sunspotcycle.com/
http://gage1.upc.es /
With SA set to Zero, the dominant error is now the
error associated with the Ionosphere.
– The ionosphere can add a significant amount of error to a
user's position solution
– Based on several factors:
gAGE
• geographic location
• time of day
• time with respect to the solar cycle (11 years).
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 20
SBAS Concept
UPC
research group of Astronomy and Geomatics
The pseurorange error is split in its components.
• Clock error
• Ephemeris error
• Ionospheric error
• Local errors (troposphere, multipath, receiver noise)
gAGE
Uses a network of receivers to cover broad geographic area
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 21
UPC
research group of Astronomy and Geomatics
Error Mitigation
Error GBAS SBAS
component
Satellite clock Estimation and
Ephemeris Common Mode Removal each
error
Ionosphere Differencing component
Troposphere Fixed Model
Multipath and Carrier Smoothing by user
Receiver Noise
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 22
UPC
GEO
research group of Astronomy and Geomatics
Integrity
GPS-like Differential (Use /
signals corrections Don't Use)
+ ACCURACY + SAFETY
+ AVAILABILITY
+ CONTINUITY
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 23
UPC The European Geoestationary Navigation
Overlay SERVICE (EGNOS)
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 24
UPC
What EGNOS is?
research group of Astronomy and Geomatics
• EGNOS is the European component of a Satellite
Based Augmentation to GPS and GLONAS.
• EGNOS is being developed under the
responsibility of a tripartite group:
– The European Space Agency (ESA)
– The European Organization for the Safety of Air
Navigation (EUROCONTROL)
– The Commission of the European Union.
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 25
UPC
Three existing SBAS Systems
research group of Astronomy and Geomatics
WAAS EGNOS MSAS
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 26
UPC
ECAC Area
(ECAC: European Civil Aviation Conference)
research group of Astronomy and Geomatics
70
Artemis
IOR
AOR-E
60
50
Latitude (°)
40
30
gAGE
20
-40 -30 -20 -10 0 10 20 30 40
Longitude (°)
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 27
UPC
EGNOS AOC Architecture
(AOC: Avanced Operational Capability)
research group of Astronomy and Geomatics
GEO
GLONASS
AOR-E GPS
IOR
ARTEMIS
RIMS
NLES
(x 7)
EWAN
gAGE
MCC 1 MCC 2 MCC 3 MCC 4 PACF ASQF
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 28
UPC
research group of Astronomy and Geomatics EGNOS AOC GROUND NETWORK TOPOLOGY
RIMS for a good GEO RANGING RIMS in ECAC
gAGE
NLES MCCs
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 29
RIMS MCC NLES ASQF PACF
UPC
research group of Astronomy and Geomatics
75
70
TRO
MMK
65
RKK FER
TRD
60
STK
SPT
GLG
ALB
55
LON
RST
CCV
50 CRK
FRK
ECAC TLS
ZRH
45 SOF
SDC SBT TBL
MAD
40 ROM
LSB MAL
PDM KON
ACR
CTN
35
MAD
DJA TAV
gAGE
30 MMT
CNR1
25
-30 -20 -10 0 10 20 30 40 50
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 30
UPC
Ranging & Integrity Monitoring Station
(RIMS)
33 RIMS in EGNOS +1
research group of Astronomy and Geomatics
specific RIMS for UTC time
GPS GLONASS GEO
L1 / L2 L1 L1
Antenna Local Maintenance
Equipment
&
SYNC Local Maintenance
Pre- amplifier Core
RIMS Computer Operator
Receiver DATA
RIMS
RIMS DATA
Atomic
Receiver SET Clock Power Supply
&
Air conditioning
FEE
EWAN
RIMS
Core SET
gAGE
CCF CPF
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 31
UPC
research group of Astronomy and Geomatics Master Control Center (MCC)
• MCC is Subdivided into
– CCF (Central Control Facility)
•
• Monitoring and control EGNOS G/S
Monitoring and control EGNOS G/S
•
• Mission Monitoring and archive
Mission Monitoring and archive
•
• ATC I/F
ATC I/F
– CPF (Central Processing Facility)
•
• Provides EGNOS WAD corrections
Provides EGNOS WAD corrections
•
• Ensures the Integrity of the EGNOS users
Ensures the Integrity of the EGNOS users
•
• Utilises independent RIMS channels for checking of corrections
Utilises independent RIMS channels for checking of corrections
•
• Real time software system developed to high software standards
Real time software system developed to high software standards
• 4 MCCs will be implemented in EGNOS
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 32
UPC
research group of Astronomy and Geomatics Master Control Center (MCC)
Check Processing Check
EWAN
FEE
CPF Central Processing Facility
EWAN
FEE
CCF Central Control Facility
Monitor Monitor ISDN
Ground mission Archive ATC I/f
Segment
gAGE
PACF
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 33
CCF VIEWS
UPC
research group of Astronomy and Geomatics
gAGE
CCF: Global Accuracy display
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 34
UPC
Navigation Land Earth Station
(NLES)
research group of Astronomy and Geomatics
Uplink the EGNOS message with GEO
FDN GPS
the GEO ranging signal to GEO. FUP
GEO L1 L1/L2
GEO L1
Frequencies
• Generate GPS-like signal andDN
Band FUP F
in MHz
transmit it to GEO transponder.
INMARSAT 3 C 6455.42 3630.42
RF
• Maintaining synchronization of
ARTEMIS Ku 13875 12748
the message with GPS time.
FUP-R
Integrity
FDN
L1
CALDN
CALL1
FUP
Box
ON/OFF
RF Adapter
Monitoring & Conrol
FUP-RL1
FDNL1
70.42 MHz
L1
CALL1
10 MHz Distribution
Core
Frequency Long 1 PPS
Receiver
Standard Loop
Rx message
message
Offset
1 PPS
Time
GEO
gAGE
Tx message
CPF Ground EWAN Core
Communication
CCF Network FEE Computer 1 PPS
GPS / GEOs / GLONASS phase and code
raw measurements
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 35
UPC
Geostationary satellite Broadcast Areas
(GBA)
research group of Astronomy and Geomatics
80
60
40
20
0
AOR -E IOR
-20
(15.5°W) (65.5°E)
INMARSAT INMARSAT
-40
PRN120 Artemis PRN131
21.5 E
(15°E)
-60
gAGE
-80
-150 -100 -50 0 50 100 150
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 36
UPC EGNOS Wide Area Network
(EWAN)
research group of Astronomy and Geomatics
Function
Links all EGNOS components RIMS RIMS
RIMS RIMS
Link types: RIMS NLES1 RIMS
MCC-MCC MCC1 MCC2
High capacity
EWAN's backbone NLES4 NLES2
MCC-NLES MCC4 MCC3
Ensures link with GEO's
RIMS NLES3 RIMS
gAGE
MCC-RIMS RIMS
RIMS
RIMS
RIMS
Frame Relay or VSAT
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 37
EGNOS System Test Bed (ESTB)
UPC
Ready for Application Demonstrations
research group of Astronomy and Geomatics
AOR-E
IOR
ESTB
Reference station
ESTB
Processing Facility
NLES
Kourou
(French Guyana)
gAGE
Hartebeeshoek
European (South Africa)
Commission
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 38
UPC
The EGNOS System Test Bed
(ESTB)
research group of Astronomy and Geomatics
•• Under ESA Contract, European industry has set-up an
Under ESA Contract, European industry has set-up an
EGNOS test bed (fully operational since Feb. 2000) ..
EGNOS test bed (fully operational since Feb. 2000)
The ESTB is a full-scale real-time prototype of the
The ESTB is a full-scale real-time prototype of the
final EGNOS system.
final EGNOS system.
•• ESTB main objectives are:
ESTB main objectives are:
– to have an assessment of the global performance
– to have an assessment of the global performance
achievable with EGNOS
achievable with EGNOS
– to analyze in depth specific critical design issues or
– to analyze in depth specific critical design issues or
trade-off’s between several options
trade-off’s between several options
– to develop and validate system test methods
– to develop and validate system test methods
– to demonstrate to the final users the system operation,
– to demonstrate to the final users the system operation,
– to provide a representative tool for Civil Aviations to
gAGE
– to provide a representative tool for Civil Aviations to
build up SBAS practical experience
build up SBAS practical experience
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 39
UPC
research group of Astronomy and Geomatics EGNOS Operational Milestones
Initial trials
System Definition
Initial
Phase Start October 98
January 96
Development/ Validation Validation Operational/
Detailed Design
implementation (ESA). certification.
21 months 21 months 9 months 24 months
Advanced
Operational
Capability
July 2000 April 2002 January 2003 Service operative
(AOC) Start
October 98 January 2005
Program ARTES-9 (ESA)
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 40
UPC
research group of Astronomy and Geomatics
Switzerland Others 214 M EUR
Norway 2% 4%
Italy 2% France
14% 32%
United Kingdom
16%
Austria
gAGE
1% Germany
Netherlands 15%
1% Portugal Spain
2% 11%
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 41
UPC
EGNOS Benefits
research group of Astronomy and Geomatics
• Aviation, maritime navigation, Railways.
• Road community: car navigation, fleet management,
road pricing, autonomous vehicle guidance, etc.
• Timing and telecommunications: synchronization of
internet nodes; synchronization of mobile base stations,
etc.
• Agriculture: precision farming, GIS applications,
automation of mobile agriculture, etc).
• Many others: fishery, search and rescue, land
surveying, meteorology, land survey, leisure, etc.
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 42
UPC
research group of Astronomy and Geomatics
PART II
Data Processing
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 43
UPC
research group of Astronomy and Geomatics
DATA PROCESSING
Navigation equations
and
SBAS Differential Corrections
and Integrity
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 44
UPC
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 45
UPC
research group of Astronomy and Geomatics PSEUDORANGE MODELING
Pij= c ∆t= c [trec(TR)-tems(TS)]
∑δ
Pi = ρ i + c ⋅ ( dt i − dt ) + ∑ δ
j j j
where:
∑
gAGE
δ = rel i j + Trop i
j
+ Ion i j + K i + TGD j
+ε j
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 46
•Pseudorange modeling
UPC
Pi j = ρ iijj + c ⋅ ( dt i − dt j ) +
ρ ∑δ k
research group of Astronomy and Geomatics
Taylor linearization of ρ:
(x − x ) +( y − y ) +(z − z ) x i0 − x y i0 − y z i0 − z
j j j
j 2 j 2 j 2
ρ ρi
i
jj
= i i i ≈ ρ j
+ ∆ xi + ∆ yi + ∆ zi
i0
ρ ij
0
ρ ij 0
ρ ij
0
xii00 − x jj y i00 − y j z i0 − z j
Pi ≈ ρ iio +
= j j
∆ xiii +
∆x ∆ yiii +
∆y ∆ z iii + c(dtii − dt j ) + ∑ δ k
( dt
0
ρ iioj
j
0
ρ iio
j
j
0
ρ iio
0
j
j
x i = x io + ∆ x i ; y i = y io + ∆ y i ; z i = z io + ∆ z i
• Navigation Equations System:
x i0 − x 1 y i0 − y 1 z i0 − z 1
1
∑
P11 − ρi1o1 + dt1 − δ k1 ρ io ρ i1 ρ i1
1
P2
2
i − ρ + dt1 −
io ∑ δ k
1 o o
∆
∆ xii
∑ x i0 − x y i0 − y z i0 − z 2
2 2
P − ρioi + d t − ∑kδ
2
2+ dt −
2
δ k
2
∆
P − ρ o
i
2 2
1 ∆yii
== ρ i2 ρ i2 ρ i2
∆zi
........ z
∆ i
........ o o o
gAGE
..........
Pnn − ρ nin++dt nt − − ∑ δ n
P − ρ
cd t i
i io o
d n ∑
δk
n
k
x i0 − x
n
y i0 − y n z i0 − z n
cdti
1
ρn ρ in ρ in
io o o
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 47
• Navigation Solution:
UPC
Y =G⋅X ∆ xi
research group of Astronomy and Geomatics
∆y
X =
i
∆zi
(G ) −1 where
NOTE:
X = T
WG T
G W Y cdt i
•NOTE
∆ xi
∆ y
xi − x j
y i0 − y j
z i0 − z j
X =
i
G j
= 0 j , , , 1 ∆ zi
ρ io ρ ij
o
ρ ij
o
cdt i
∆N i
[
G j = cosElij cos Azij , cosElij sin Azij , sin Elij ,1 ] ∆E
gAGE
X =
i
∆U i
cdt i
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 48
PROTECTION LEVELS:
UPC Y =G⋅X
X = [∆ N , ∆ E , ∆ U , cdt ]
X = G WG ( T
)
−1
GTW Y
research group of Astronomy and Geomatics
dN 2
d NE d NV d NT
2
d NE dE d EV d ET 2
Px = S Py S =
T
d N + dE
2 2
d N − dE
2 2
d NV d V2 dVT
d EV HPL = 6.00 + + d NE
2
d T2 2 2
d NT
d ET dVT
S = ( G WG ) G T W
T -1
VPL = 5.33 dV
w1 0
W=
wi = (σ i2,UDRE + σ i2,UIRE|ε =0 + σ i2,air + σ i2,tropo )
−1
0
wN
-Kσ-σ σ Kσ
σ 12 0
X ~ N (0,1)
gAGE
Py = σ i2 = σ i2, flt + σ i2,UIRE + σ i2,air + σ i2,tropo
P ( X > 5.33) = 10 −7
0 σN
2
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 49
Users know the receiver-satellites geometry and can compute bounds on
UPC the horizontal and vertical position errors.
These bounds are called Protection Levels (HPL and VPL). They provide
good confidence (10-7/hour probability) that the true position is within a
research group of Astronomy and Geomatics
bubble around the computed position.
Protection
Level
True
Error
-Kσ-σ σ Kσ Tail area Probability P(VPE>VPL) < 10-7 /sample
N
VPL = KV ∑s 2
σ 2
σ i2 = σ i2, flt + σ i2,UIRE + σ i2,air + σ i2,tropo
gAGE
Vi i
i =1
GEOMETRY
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 50
Fast Corrections
UPC Ephemeris +
Long Term Corrections MT1, MT2,5,24, MT6,
+ + MT25, MT7, MT12,
research group of Astronomy and Geomatics
UDRE MT9
Clocks +
Degradation Param.
MT10
IONO Corrections
+ MT18
IONO GIVE MT26
+
Degradation Param.
Y = C1 + PRC − ρ * + ∆ t sat + dt sat + rel − TGD + IONO + TROP
IONO
gAGE
σ 2 = σ 2 + σ UIRE + σ air + σ tropo
flt
2 2 2
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 51
Fast and Long-Term Correction Degradation
UPC
σ
( + ε fc + ε rrc + ε ltc + ε er , if )
2
RSSUDRE = 0 ( MT10)
σ 2
= UDRE
research group of Astronomy and Geomatics
i , flt
σ 2UDRE + ε 2 fc + ε 2 rrc + ε 2ltc + ε 2er , if
RSSUDRE = 1 ( MT10)
(t −tu +tlat )
2
MT25
ε fc =a 2
MT2-6,24 tltc , v0 or v1
= Cltc ,v 0 floor I ltc
t −t
ε ltc,v0
IODF ,UDREi
ltc,v 0 tu = tof MT7
( when IODF ≠ 3)
ai I fc ,i tlat
0
, if t0 < t < t0 + I ltc _ v1
ε ltc,v1 =
Clts _ lsb + Cltc _ v1 max {0, t0 − t , t − t0 − I ltc _ v1} , otherwise
MT10
Brrc , Cltc _ lsb , Cltc _ v1,
0
ε er
Neither fast nor long term corrections
= have time out for precision approach
Cer Otherwise Iltc _ v1, Cltc _ v0 , Iltc _ v0 ,
IODF , IODF ≠3
IODFcurrent , IODFprevious ≠ 3 Cer , RSSUDRE ,
0 , ( IODF =1
current previous
− IODFprevious ) mod 2
gAGE
ε rrc
current
= a I fc Brrc Ciono _ ramp , Ciono _ step ,
(
4 + ∆t
) ( t − tof ) , ( IODFcurrent − IODFprevious ) mod 2 ≠1
Iiono , RSSiono
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 52
Degradation of Ionospheric Corrections
UPC
1
2 −2
R cos E
σ 2
=F σ2 2 Fpp = 1 − e
research group of Astronomy and Geomatics
UIRE pp UIVE Re + hI
N
σ 2
UIVE = ∑Wn ( x pp , y pp ) σ n,ionogrid , N = 4 or 3
2
MT10
n =1 Brrc , Cltc _ lsb , Cltc _ v1,
Iltc _ v1, Cltc _ v0 , Iltc _ v0 ,
(σ GIVE + ε iono
)
2
, if RSSiono = 0 ( MT10)
σ 2
ionogrid = Cer , RSSUDRE ,
σ GIVE + ε iono RSSiono = 1 ( MT10)
2 2
, if
Ciono _ ramp , Ciono _ step ,
Iiono , RSSiono
εiono = Ciono _ step floor ( t −iono ) + Ciono _ ramp ( t − tiono )
I
tiono
MT26
gAGE
tiono ,GIVEi
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 53
UPC SBAS Differential Corrections and Integrity:
The RTCA/MOPS
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 54
UPC
research group of Astronomy and Geomatics
Message Format
DIRECTION OF DATA FLOW FROM SATELLITE; MOST SIGNIFICANT BIT (MSB) TRANSMITTED FIRST
250 BITS - 1 SECOND
IODP (2 BITS) REPEAT FOR 12
REPEAT FOR 12 MORE SATELLITES UDREI MORE SATELLITES
PRCf 212-BIT DATA FIELD
13 12-BIT FAST CORRECTIONS 13 4-BIT UDREIs 24-BITS
PARITY
IODF (2 BITS)
6-BIT MESSAGE TYPE IDENTIFIER (= 2, 3, 4 & 5)
8-BIT PREAMBLE OF 24 BITS TOTAL IN 3 CONTIGUOUS BLOCKS
The corrections, even for
individual satellites are
distributed across several
• 250 bits individual messages.
• One Message per second
gAGE
• All messages have identical format
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 55
UPC
EGNOS Broadcast Messages (ICAO SARPS)
MSG 0 Don't use this SBAS signal for anything (for SBAS testing)
research group of Astronomy and Geomatics
MSG 1 PRN Mask assignments, set up to 51 of 210 bits
MSG 2 to 5 Fast corrections
MSG 6 Integrity information
MSG 7 Fast correction degradation factor
MSG 8 Reserved for future messages
MSG 9 GEO navigation message (X, Y, Z, time, etc.)
MSG 10 Degradation Parameters
MSG 11 Reserved for future messages
MSG 12 SBAS Network Time/UTC offset parameters
MSG 13 to 16 Reserved for future messages
MSG 17 GEO satellite almanacs
Many Message Types
MSG 18 Ionospheric grid point masks Coordinated Through
MSG 19 to 23 Reserved for future messages Issues Data (IOD)
MSG 24 Mixed fast corrections/long term satellite error corrections
MSG 25 Long term satellite error corrections
MSG 26 Ionospheric delay corrections
MSG 27 SBAS outside service volume degradation
gAGE
MSG 28 to 61 Reserved for future messages
MSG 62 Internal Test Message
MSG 63 Null Message
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 56
Fast Corrections
UPC Ephemeris +
Long Term Corrections MT1, MT2,5,24, MT6,
+ + MT25, MT7, MT12,
research group of Astronomy and Geomatics
UDRE MT9
Clocks +
Degradation Param.
MT10
IONO Corrections
+ MT18
IONO GIVE MT26
+
Degradation Param.
Y = C1 + PRC − ρ * + ∆ t sat + dt sat + rel − TGD + IONO + TROP
IONO
gAGE
σ 2 = σ 2 + σ UIRE + σ air + σ tropo
flt
2 2 2
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 57
UPC
research group of Astronomy and Geomatics
Issues of Data (IOD)
GPS IODEk IODk Long-term No IOD: Fast
repeat msg, Corrections
Ephemeris Corrections
small (2 - 5, 24)
(25) changes
IODCk
IODGk IODP IODFj
GPS
IODP
Clock
PRN Integrity
GLONASS
Mask Information
DATA
(1) (6)
IODS IODP
Service Acceleration
Message Information
(27) (7)
gAGE
Ionospheric Ionospheric
Mask Corrections
(18) IODI
(26)
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 58
UPC Message Time-Outs:
Users can operate even when missing Messages
research group of Astronomy and Geomatics
• Prevents Use of Very Old Data
• Confidence Degrades When Data is Lost
• IODF: Detect Missing Fast Corrections
1 second
System Latency
The Correction is tof: Time of applicability Last bit of message:
estimated by the (1st bit of message) tof+1sec
gAGE
master station
Correction time-Out
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 59
Associated Maximum En Route, Precision
UPC Data Message Update Interval Terminal, NPA Approach
Types (seconds) Timeout (seconds) Timeout (seconds)
WAAS in Test Mode 0 6 N/A N/A
research group of Astronomy and Geomatics
PRN Mask 1 60 None None
UDREI 2-6, 24 6 18 12
Fast Corrections 2-5, 24 60 (*) (*)
Long Term 24, 25 120 360 240
Corrections
GEO Nav. Data 9 120 360 240
Fast Correction 7 120 360 240
Degradation
Weighting Factors 8 120 240 240
Degradation 10 120 360 240
Parameters
Ionospheric Grid 18 300 None None
Mask
Ionospheric 26 300 600 600
Corrections
gAGE
UTC Timing Data 12 300 None None
Almanac Data 17 300 None None
(*) Fast Correction Time-Out intervals are given in MT7 [between 12 to 120 sec]
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 60
UPC
research group of Astronomy and Geomatics PRN MASK (MT01)
Bit No 1 2 3 4 5 6 . 38 . 120 . 210
Value 0 1 0 1 1 0 1 1 0
PRN GPS GPS GPS GLONASS AORE
PRN 2 PRN 4 PRN 5 Slot 1 PRN 120
PRN mask 1 2 3 21 29
Number
Each MT01 contains its associated IODP
Assignment
Up to 51 satellites in 210 slots. PRN
Slot
1-37 GPS/GPS Reserved
Note: Each Correction set in 38-61 GLONASS
MT 2-5,5,6,7,24,25 its 62-119 Future GNSS
characterized by its PRN-Mask 120-138 GEO/SBAS
gAGE
number, between 1 to 51. 139-210 Future GNSS/GEO/SBAS/Pseudolites
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 61
UPC
research group of Astronomy and Geomatics
Fast Corrections (MT2-5,24)
• Primarily Removes SA
– Common to ALL users
– Up to 13 Satellites Per Message
– Pseudorange Correction /confidence Bound
– Range Rate Formed by Differencing
– UDRE degrades Over Time
• Acceleration Term in MT 7
• Reset when new Message Received
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 62
UPC
research group of Astronomy and Geomatics
Fast Corrections (MT2-5)
PRC (t ) = PRC n + RRC n (t − t n )
(t Y = C1 + PRC − ρ * + ∆ t sat + dt sat
PRC n − PRC o
RRC n = + rel − TGD + IONO + TROP
tn − to
DIRECTION OF DATA FLOW FROM SATELLITE; MOST SIGNIFICANT BIT (MSB) TRANSMITTED FIRST
250 BITS - 1 SECOND
IODP (2 BITS) REPEAT FOR 12
REPEAT FOR 12 MORE SATELLITES UDREI MORE SATELLITES
PRCf
13 12-BIT FAST CORRECTIONS 13 4-BIT UDREIs 24-BITS
PARITY
IODF (2 BITS)
6-BIT MESSAGE TYPE IDENTIFIER (= 2, 3, 4 & 5)
8-BIT PREAMBLE OF 24 BITS TOTAL IN 3 CONTIGUOUS BLOCKS
gAGE
( RSS UDRE = 0 [MT 10 ])
σ 2i, flt = σ 2UDRE + ε 2 fc + ε 2rrc + ε 2ltc + ε 2er
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 63
UPC
Message Type 6
DIRECTION OF DATA FLOW FROM SATELLITE; MOST SIGNIFICANT BIT (MSB) TRANSMITTED FIRST
research group of Astronomy and Geomatics
250 BITS - 1 SECOND
IODF2, IODF3, IODF4 & IODF5 (2 BITS EACH)
51 4-BIT UDREIs 24-BITS
PARITY
6-BIT MESSAGE TYPE IDENTIFIER (= 6)
8-BIT PREAMBLE OF 24 BITS TOTAL IN 3 CONTIGUOUS BLOCKS
Alarm conditions are
• Serves Two Purposes indicated with
IODF=3
– Alarm for Multiple Satellites
• Includes UDREs for all 51 Satellites
– Update UDRE in Between Fast Corrections
• More efficient Use of Bandwidth
gAGE
• The receipt of MT6 with matching IODF<3 is equivalent
to another reception of last fast correction.
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 64
Evaluation of UDREI
UPC
UDREIi UDREi Meters σ2i,UDRE Comment:
Meters2
research group of Astronomy and Geomatics
0 0.75 0.0520 • With SA=off, the FC can be sent
1 1.0 0.0924 less frequently than 6sec, but it is
2 1.25 0.1444
still necessary to update the
“integrity status (UDREs)” at the
3 1.75 0.2830
high rate.
4 2.25 0.4678
5 3.0 0.8315 • Prec. App: UDRE time-out =12sec
6 3.75 1.2992 FC time-out between 12 -120 sec.
7 4.5 1.8709
8 5.25 2.5465
9 6.0 3.3260
The MOPS (RTCA Do 229A) 2.1.1.5.2,
10 7.5 5.1968 establish the satellites deselecting for:
11 15.0 20.7870 -UDRE=14 (not monitored)
12 50.0 230.9661 and
-UDRE=15 (don’t use)
13 150.0 2078.695
gAGE
14 Not Monitored Not Monitored 2.1.4.7.1: In addition, for
15 Do Not Use Do Not Use Precision Approach: UDRE<11.
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 65
UPC UDRE degradation: The fast correction was estimated
UDRE degradation: The fast correction was estimated
by master station at some previous time tt -tlat
by master station at some previous time nn-tlat
research group of Astronomy and Geomatics
1 sec
tlat (MT 7) Ifc (MT 7)
The Correction is
estimated by the
tn: Time of applicability
master station (1st bit of message)
σ2i, flt =σ2UDRE +ε2 fc +ε2rrc +ε2ltc +ε2er FC Correction
time-Out
Acceleration Term Lost Fast Correction Term
(Always included) ( when IODF ≠ 3)
a I fc Brrc
ε fc
a
≡ (t − tUDRE + t lat )
2 ε rrc ≡
4 + t −t (t − t n )
gAGE
2 n o
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 66
UPC
research group of Astronomy and Geomatics
EXAMPLE 1
(From WAAS MOPS: Practical Examples.
Todd Walter)
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 67
Time
(sec)
Last
Mess.
Last
Mess
Last
Mess. PRC(t) RRCn Error
σ2flt σ2UDRE ε2fc ε2rrc
UPC t Time (s)
tn
PRCn
(m)
IODFn (m) (m)
0 -1 0.500 0 - - - - - -
research group of Astronomy and Geomatics
3 -1 0.500 0 - - - - - -
6 5 -2.125 1 -2.563 -0.4375 0.505 0.0957 0.0924 0.0033 0
9 5 -2.125 1 -3.875 -0.4375 1.045 0.1141 0.0924 0.0217 0
12 11 -3.125 2 -3.292 -0.1667 -0.140 0.0957 0.0924 0.0033 0
15 11 -3.125 2 -3.792 -0.1667 -0.171 0.1141 0.0924 0.0217 0
18 17 -4.000 0 -4.146 -0.1458 0.238 0.0957 0.0924 0.0033 0
21 17 -4.000 0 -4.583 -0.1458 0.373 0.1141 0.0924 0.0217 0
24 17 -4.000 0 -5.021 -0.1458 0.893 0.1699 0.0924 0.0775 0
27 17 -4.000 0 -5.458 -0.1458 1.584 0.2954 0.0924 0.2030 0
30 29 -3.500 2 -3.458 0.0417 0.008 0.0964 0.0924 0.0033 0.00069
33 29 -3.500 2 -3.333 -0.0417 0.479 0.1252 0.0924 0.0217 0.01111
36 35 -2.750 0 -2.625 0.1250 0.537 0.0957 0.0924 0.0033 0
39 35 -2.750 0 -2.250 0.1250 1.100 0.1141 0.0924 0.0217 0
FC update rate 6 sec
Param Mes. Type value Param Mes. Type value
σ2UDRE (m2) MT 2 0.0924
tlat (sec) MT 7 4
gAGE
a (mm/s2) MT 7 4.60
Brrc (m) MT10 0.15
Ifc (sec) MT 7 12
RSSUDRE MT10 1
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 68
Time
(sec)
Last
Mess.
Last
Mess
Last
Mess. PRC(t) RRCn Error
σ2flt σ2UDRE ε2fc ε2rrc
UPC t Time (s)
tn
PRCn
(m)
IODFn (m) (m)
0 -1 0.500 0 - - - - - -
research group of Astronomy and Geomatics
3 -1 0.500 0 - - - - - -
6 5 -2.125 1 -2.563 -0.4375 0.505 0.0957 0.0924 0.0033 0
9 5 -2.125 1 -3.875 -0.4375 1.045 0.1141 0.0924 0.0217 0
12 11 -3.125 2 -3.292 -0.1667 -0.140 0.0957 0.0924 0.0033 0
15 11 -3.125 2 -3.792 -0.1667 -0.171 0.1141 0.0924 0.0217 0
18 17 -4.000 0 -4.146 -0.1458 0.238 0.0957 0.0924 0.0033 0
21 17 -4.000 0 -4.583 -0.1458 0.373 0.1141 0.0924 0.0217 0
24 17 -4.000 0 -5.021 -0.1458 0.893 0.1699 0.0924 0.0775 0
27 17 -4.000 0 -5.458 -0.1458 1.584 0.2954 0.0924 0.2030 0
30 29 -3.500 2 -3.458 0.0417 0.008 0.0964 0.0924 0.0033 0.00069
33 29 -3.500 2 -3.333 -0.0417 0.479 0.1252 0.0924 0.0217 0.01111
36 35 -2.750 0 -2.625 0.1250 0.537 0.0957 0.0924 0.0033 0
39 35 -2.750 0 -2.250 0.1250 1.100 0.1141 0.0924 0.0217 0
PRC (t ) = PRC n + RRC n (t − t n )
n n n σ2i, flt =σ2UDRE +ε2 fc +ε2rrc +ε2ltc +ε2er
PRC n − PRC o
RRC n = a a I B
t n − to ε fc ≡ (t − t n + tlat )2 ε rrc ≡ fc
4 + t −t
rrc
(t − t n )
2
gAGE
n o
RRC Time − Out Ifc=12sec
PRC Time − Out εrrc=0 when no mess. are missed
∆ t = t n − t o > I fc UDRE Time-Out
t − t n > 8∆t t − t n > I fc + 1 t-tn>13
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 69
Time
(sec)
Last
Mess.
Last
Mess
Last
Mess. PRC(t) RRCn Error
σ2flt σ2UDRE ε2fc ε2rrc
UPC t Time (s)
tn
PRCn
(m)
IODFn (m) (m)
0 -1 0.500 0 - - - - - -
research group of Astronomy and Geomatics
3 -1 0.500 0 - - - - - -
6 5 -2.125 1 -2.563 -0.4375 0.505 0.0957 0.0924 0.0033 0
9 5 -2.125 1 -3.875 -0.4375 1.045 0.1141 0.0924 0.0217 0
12 11 -3.125 2 -3.292 -0.1667 -0.140 0.0957 0.0924 0.0033 0
15 11 -3.125 2 -3.792 -0.1667 -0.171 0.1141 0.0924 0.0217 0
18 17 -4.000 0 -4.146 -0.1458 0.238 0.0957 0.0924 0.0033 0
21 17 -4.000 0 -4.583 -0.1458 0.373 0.1141 0.0924 0.0217 0
24 17 -4.000 0 -5.021 -0.1458 0.893 0.1699 0.0924 0.0775 0
27 17 -4.000 0 -5.458 -0.1458 1.584 0.2954 0.0924 0.2030 0
30 29 -3.500 2 -3.458 0.0417 0.008 0.0964 0.0924 0.0033 0.00069
33 29 -3.500 2 -3.333 -0.0417 0.479 0.1252 0.0924 0.0217 0.01111
36 35 -2.750 0 -2.625 0.1250 0.537 0.0957 0.0924 0.0033 0
39 35 -2.750 0 -2.250 0.1250 1.100 0.1141 0.0924 0.0217 0
PRC (t ) = PRC n + RRC n (t − t n ) σ2i, flt =σ2UDRE +ε2 fc +ε2rrc +ε2ltc +ε2er
PRC n − PRC o
RRC n = a a I B
t n − to ε fc ≡ (t − t n + tlat )2 4 + t − t (t − t n )
ε rrc ≡ fc rrc
2
gAGE
n o
RRC Time − Out Ifc=12sec
PRC Time − Out εrrc=0 when no mess. are missed
∆ t = t n − t o > I fc UDRE Time-Out
t − t n > 8∆t t − t n > I fc + 1 t-tn>13
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 70
Time
(sec)
Last
Mess.
Last
Mess
Last
Mess. PRC(t) RRCn Error
σ2flt σ2UDRE ε2fc ε2rrc
UPC t Time (s)
tn
PRCn
(m)
IODFn (m) (m)
0 -1 0.500 0 - - - - - -
research group of Astronomy and Geomatics
3 -1 0.500 0 - - - - - -
The IODEs are not in
6 5 -2.125 1 -2.563
sequence and the user is 0.0957
-0.4375 0.505 0.0924 0.0033 0
9 5 -2.125 1 aware that a FC is missing.
-3.875 -0.4375 1.045 0.1141 0.0924 0.0217 0
12 11 -3.125 2 is formed using
RRC -0.1667 -0.140IODFs
-3.292 0.0957 0.0924 0.0033 0
-3.792 of sequence => ε rrc
out -0.1667 -0.171 2
15 11 -3.125 2 0.1141 0.0924 0.0217 0
18 17 -4.000 0 -4.146 -0.1458 0.238 0.0957 0.0924 0.0033 0
21 17 -4.000 0 -4.583 -0.1458 0.373 0.1141 0.0924 0.0217 0
24 17 -4.000 0 -5.021 -0.1458 0.893 0.1699 0.0924 0.0775 0
27 17 -4.000 0 -5.458 -0.1458 1.584 0.2954 0.0924 0.2030 0
30 29 -3.500 2 -3.458 0.0417 0.008 0.0964 0.0924 0.0033 0.00069
33 29 -3.500 2 -3.333 -0.0417 0.479 0.1252 0.0924 0.0217 0.01111
36 35 -2.750 0 -2.625 0.1250 0.537 0.0957 0.0924 0.0033 0
39 35 -2.750 0 -2.250 0.1250 1.100 0.1141 0.0924 0.0217 0
PRC (t ) = PRC n + RRC n (t − t n ) σ2i, flt =σ2UDRE +ε2 fc +ε2rrc +ε2ltc +ε2er
PRC n − PRC o
RRC n = a a I B
t n − to ε fc ≡ (t − t n + tlat )2 4 + t − t (t − t n )
ε rrc ≡ fc rrc
2
gAGE
n o
RRC Time − Out Ifc=12sec
PRC Time − Out εrrc=0 when no mess. are missed
∆ t = t n − t o > I fc UDRE Time-Out
t − t n > 8∆t t − t n > I fc + 1 t-tn>13
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 71
UPC
research group of Astronomy and Geomatics
EXAMPLE 2
(From WAAS MOPS: Practical Examples.
Todd Walter)
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 72
σ2i, flt =σ2UDRE +ε2fc +ε2rrc +ε2ltc +ε2er a
Time Last Mes Last Mess Last Mes tUDRE σ2 σ2 ε2 ε2 ε fc ≡ (t − tUDRE + tlat )2
UPC (sec) Time (s) Type IODF flt UDRE fc rrc 2
a I B
4 + t − t (t − t n )
0 -1 2 0 -1 0.052014 0.0520 0.000014 0
ε rrc ≡ fc rrc
6 5 6 0 5 0.052014 0.0520 0.000014 0 n o
research group of Astronomy and Geomatics
12 11 6 0 11 0.052014 0.0520 0.000014 0
18 17 6 0 17 0.092414 0.0924 0.000014 0
24 23 6 0 23 0.092414 0.0924 0.000014 0 εrrc=0 when no
30 29 2 1 29 0.052014 0.0520 0.000014 0 messages are missed
36 35 6 1 35 0.052014 0.0520 0.000014 0
42 41 6 1 41 0.052014 0.0520 0.000014 0
48 47 - - 41 0.052329 0.0520 0.000329 0
54 53 6 1 53 0.092414 0.0924 0.000014 0
60 59 - - 53 0.092729 0.0924 0.000329 0
66 65 6 2 53 0.094297 0.0924 0.001897 0 Param Mes. value
72 71 6 2 53 0.092696 0.0924 0.006296 0 Type
78 77 6 2 53 0.108310 0.0924 0.015910 0 σ2UDRE 0.0520
MT 2,6 0.0924
84 83 6 2 53 0.430000 0.0924 0.337600 0 (m2)
90 89 2 0 89 0.052074 0.0520 0.000014 0.000060 a
MT 7 0.30
96 95 6 0 95 0.054732 0.0520 0.000014 0.002720 (mm/s2)
102 101 6 0 101 0.061394 0.0520 0.000014 0.009380
Ifc (sec) MT 7 66
108 107 6 0 107 0.122814 0.0924 0.000014 0.030400
114 113 6 0 113 0.027104 0.0924 0.000014 0.034690 tl (sec) MT 7 4
120 119 2 1 119 0.052014 0.0520 0.000014 0
Brrc (m) MT10 0.15
126 125 6 1 125 0.052014 0.0520 0.000014 0
RSSUDRE MT10 1
gAGE
132 131 6 1 131 0.052014 0.0520 0.000014 0
138 137 6 3 119 0.092696 0.0924 0.006296 0
144 143 6 3 119 0.108310 0.0924 0.015910 0 MT 2 update rate 30 sec
150 149 2 2 149 0.052014 0.0520 0.000014 0 MT 6 update rate 6 sec
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 73
σ2i, flt =σ2UDRE +ε2fc +ε2rrc +ε2ltc +ε2er a
Time Last Mes Last Mess Last Mes tUDRE σ2 σ2 ε2 ε2 ε fc ≡ (t − tUDRE + tlat )2
UPC t (s) t2, t6 (s) Type IODF flt UDRE fc rrc 2
a I B
4 + t − t (t − t n )
0 -1 2 0 -1 0.052014 0.0520 0.000014 0
ε rrc ≡ fc rrc
6 5 6 0 5 0.052014 0.0520 0.000014 0 n 0
o
research group of Astronomy and Geomatics
12 11 6 0 11 0.052014 0.0520 0.000014 0
18 17 6 0 17 0.092414 0.0924 0.000014 0
24 23 6 0 23 0.092414 0.0924 0.000014 0
The receipt of MT 6 (with
IODF<3) is equivalent
30 29 2 1 29 0.052014 0.0520 0.000014 0
to another reception of
36 35 6 1 35 0.052014 0.0520 0.000014 0
last fast correction
42 41 6 1 41 0.052014 0.0520 0.000014 0
48 47 - - 41 0.052329 0.0520 0.000329 0
54 53 6 1 53 0.092414 0.0924 0.000014 0 UDRE Time-Out
60 59 - - 53 0.092729 0.0924 0.000329 0 t-tUDRE>13
66 65 6 2 53 0.094297 0.0924 0.001897 0
72 71 6 2 53 0.092696 0.0924 0.006296 0
78 77 6 2 53 0.108310 0.0924
PRC (t ) = PRC n + RRC n (t − t n )
0.015910 0
84 83 6 2 53 0.430000 0.0924 0.337600 0
PRC n − PRC o
90 89 2 0 89 0.052074 0.0520 RRC n =
0.000014 0.000060
96 95 6 0 95 0.054732 0.0520 0.000014 0.002720 t n − to
102 101 6 0 101 0.061394 0.0520 0.000014 0.009380
108 107 6 0 107 0.122814 0.0924 0.000014 0.030400 RRC Time − Out
114 113 6 0 113 0.027104 0.0924 0.000014 0.034690 ∆ t = t n − t o > I fc
120 119 2 1 119 0.052014 0.0520 0.000014 0
t − t n > 8∆ t
126 125 6 1 125 0.052014 0.0520 0.000014 0
gAGE
132 131 6 1 131 0.052014 0.0520 0.000014 0 PRC Time − Out
138 137 6 3 119 0.092696 0.0924 0.006296 0
t − tUDRE > I fc + 1
144 143 6 3 119 0.108310 0.0924 0.015910 0
150 149 2 2 149 0.052014 0.0520 0.000014 0 Ifc=66sec
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 74
σ2i, flt =σ2UDRE +ε2fc +ε2rrc +ε2ltc +ε2er a
Time Last Mes Last Mess Last Mes tUDRE σ2 σ2 ε2 ε2 ε fc ≡ (t − tUDRE + tlat )2
UPC t (s) t2, t6 (s) Type IODF flt UDRE fc rrc 2
a I B
4 + t − t (t − t n )
0 -1 2 0 -1 0.052014 0.0520 0.000014 0
ε rrc ≡ fc rrc
6 5 6 0 5 0.052014 0.0520 0.000014 0 n o
research group of Astronomy and Geomatics
12 11 6 0 11 0.052014 0.0520 0.000014 0
18 17 6 0 17 0.092414 0.0924 0.000014 0
MT 6 is missed and
24 23 6 0 23 0.092414 0.0924 0.000014 0
tUDRE remains at 41s,
30 29 2 1 29 0.052014 0.0520 0.000014 0
inflating the ε2fc term
36 35 6 1 35 0.052014 0.0520 0.000014 0
42 41 6 1 41 0.052014 0.0520 0.000014 0
UDRE Time-Out
48 47 - - 41 0.052329 0.0520 0.000329 0
t-tUDRE>13
54 53 6 1 53 0.092414 0.0924 0.000014 0
60 59 - - 53 0.092729 0.0924 0.000329 0
66 65 6 2 53 0.094297 0.0924 0.001897 0
72 71 6 2 53 0.092696 0.0924 0.006296 0
78 77 6 2 53 0.108310 0.0924
PRC (t ) = PRC n + RRC n (t − t n )
0.015910 0
84 83 6 2 53 0.430000 0.0924 0.337600 0
PRC n − PRC o
90 89 2 0 89 0.052074 0.0520 RRC n =
0.000014 0.000060
96 95 6 0 95 0.054732 0.0520 0.000014 0.002720 t n − to
102 101 6 0 101 0.061394 0.0520 0.000014 0.009380
108 107 6 0 107 0.122814 0.0924 0.000014 0.030400
RRC Time − Out
114 113 6 0 113 0.027104 0.0924 0.000014 0.034690 ∆ t = t n − t o > I fc
120 119 2 1 119 0.052014 0.0520 0.000014 0
t − t n > 8∆ t
126 125 6 1 125 0.052014 0.0520 0.000014 0
gAGE
132 131 6 1 131 0.052014 0.0520 0.000014 0 PRC Time − Out
138 137 6 3 119 0.092696 0.0924 0.006296 0
t − tUDRE > I fc + 1
144 143 6 3 119 0.108310 0.0924 0.015910 0
150 149 2 2 149 0.052014 0.0520 0.000014 0 Ifc=66sec
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 75
σ2i, flt =σ2UDRE +ε2fc +ε2rrc +ε2ltc +ε2er a
Time Last Mes Last Mess Last Mes tUDRE σ2 σ2 ε2 ε2 ε fc ≡ (t − tUDRE + tlat )2
UPC t (s) t2, t6 (s) Type IODF flt UDRE fc rrc 2
a I B
4 + t − t (t − t n )
0 -1 2 0 -1 0.052014 0.0520 0.000014 0
ε rrc ≡ fc rrc
6 5 6 0 5 0.052014 0.0520 0.000014 0 n o
research group of Astronomy and Geomatics
12 11 6 0 11 0.052014 0.0520 0.000014 0
18 17 6 0 17 0.092414 0.0924 0.000014 0
IODF out of sequence,
24 23 6 0 23 0.092414 0.0924 0.000014 0
tUDRE will remain at 53s
30 29 2 1 29 0.052014 0.0520 0.000014 0 until the receip of the
36 35 6 1 35 0.052014 0.0520 0.000014 0 next fast correction
42 41 6 1 41 0.052014 0.0520 0.000014 0
48 47 - - 41 0.052329 0.0520 0.000329 0 UDRE Time-Out
54 53 6 1 53 0.092414 0.0924 0.000014 0
t-t6>13
60 59 - - 53 0.092729 0.0924 0.000329 0
66 65 6 2 53 0.094297 0.0924 0.001897 0
72 71 6 2 53 0.092696 0.0924 0.006296 0
78 77 6 2 53 0.108310 0.0924
PRC (t ) = PRC n + RRC n (t − t n )
0.015910 0
84 83 6 2 53 0.430000 0.0924 0.337600 0
PRC n − PRC o
90 89 2 0 89 0.052074 0.0520 RRC n =
0.000014 0.000060
96 95 6 0 95 0.054732 0.0520 0.000014 0.002720 t n − to
102 101 6 0 101 0.061394 0.0520 0.000014 0.009380
108 107 6 0 107 0.122814 0.0924 0.000014 0.030400 RRC Time − Out
114 113 6 0 113 0.027104 0.0924 0.000014 0.034690 ∆ t = t n − t o > I fc
user
NOTE: Because the IODF was not set to 3 and the0.0520 has
Because the IODF 1
NOTE: 119
120 2 was not set to 3 and the user has
119 0.052014 0.000014 0
not missed 4 messages in row, they know that the service t − t n > 8∆ t
not missed 4 messages in row, they know that the service
126 125 6 1 125 0.052014 0.0520 0.000014 0
provided is monitoring this and other combinations of old
gAGE
other combinations of old
provided is monitoring this and 131 PRC Time − Out
132 131 6
data and it is save for them to continue0.052014
1
it use. 0.0520 0.000014 0
data and it is save for them to continue it use. 0.0924
138 137 6 3 119 0.092696
Thence, it is using t-t6>13, instead of t-tUDRE>13 for
0.006296 0
t − tUDRE > I fc + 1
Thence, it is using t-t6>13, instead 0.108310UDRE0.0924 for 0.015910
144 143 6 3 119 of t-t >13 0
UDRE Time-Out. .
UDRE Time-Out
150 149 2 2 149 0.052014 0.0520 0.000014 0 Ifc=66sec
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 76
σ2i, flt =σ2UDRE +ε2fc +ε2rrc +ε2ltc +ε2er a
Time Last Mes Last Mess Last Mes tUDRE σ2 σ2 ε2 ε2 ε fc ≡ (t − tUDRE + tlat )2
UPC t (s) t2, t6 (s) Type IODF flt UDRE fc rrc 2
a I B
4 + t − t (t − t n )
0 -1 2 0 -1 0.052014 0.0520 0.000014 0
ε rrc ≡ fc rrc
6 5 6 0 5 0.052014 0.0520 0.000014 0 n o
research group of Astronomy and Geomatics
12 11 6 0 11 0.052014 0.0520 0.000014 0
18 17 6 0 17 0.092414 0.0924 0.000014 0 The user is aware of a FC is
24 23 6 0 23 0.092414 0.0924 0.000014 0 missing.
30 29 2 1 29 0.052014 0.0520 0.000014 0 RRC is formed using IODFs
36 35 6 1 35 0.052014 0.0520 0.000014 0 out of sequence => ε2rrc
42 41 6 1 41 0.052014 0.0520 0.000014 0
48 47 - - 47 0.052329 0.0520 0.000329 PRC (t ) = PRC n + RRC n (t − t n )
0
54 53 6 1 53 0.092414 0.0924 0.000014 0
PRC n − PRC o
60 59 - - 53 0.092729 0.0924 0.000329
RRC n0 =
66 65 6 2 53 0.094297 0.0924 0.001897 0 t n − to
72 71 6 2 53 0.092696 0.0924 0.006296 0
78 77 6 2 53 0.108310 0.0924 0.015910 0
84 83 6 2 53 0.430000 0.0924 0.337600 0
RRC Time − Out
90 89 2 0 89 0.052074 0.0520 0.000014 0.000060 ∆ t = t n − t o > I fc
96 95 6 0 95 0.054732 0.0520 0.000014 0.002720
t − t n > 8∆t
102 101 6 0 101 0.061394 0.0520 0.000014 0.009380
108 107 6 0 107 0.122814 0.0924 0.000014 0.030400
PRC Time − Out
114 113 6 0 113 0.027104 0.0924 0.000014 0.034690
120 119 2 1 119 0.052014 0.0520 0.000014 0 t − tUDRE > I fc + 1
126 125 6 1 125 0.052014 0.0520 0.000014 0
gAGE
132 131 6 1 131 0.052014 0.0520 0.000014 0 UDRE Time-Out
138 137 6 3 119 0.092696 0.0924 0.006296 0 t-tUDRE>13
144 143 6 3 119 0.108310 0.0924 0.015910 0
150 149 2 2 149 0.052014 0.0520 0.000014 0 Ifc=66sec
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 77
σ2i, flt =σ2UDRE +ε2fc +ε2rrc +ε2ltc +ε2er ε fc ≡
a
( t − 119 + tlat )
2
2
Time Last Mes Last Mess Last Mes tUDRE σ2flt σ2UDRE ε2fc ε2rrc
UPC t (s) t2, t6 (s) Type IODF
IO D F = 3; if ∆ t − I fc / 2 ≠ 0
0 -1 2 0 -1 0.052014 0.0520 0.000014 0
a ∆ t − I fc / 2 B rrc
6 5 6 0 5 0.052014 0.0520 0.000014 0 ε rrc ≡ + ( t − 11 9 )
2 ∆t
research group of Astronomy and Geomatics
12 11 6 0 11 0.052014 0.0520 0.000014 0
18 17 6 0 17 0.092414 0.0924 0.000014 0 Alarm Condition (IODF=3)
24 23 6 0 23 0.092414 0.0924 0.000014 0 tUDRE backs to 119 (the last
30 29 2 1 29 0.052014 0.0520 0.000014 0 received Fast Correction)
36 35 6 1 35 0.052014 0.0520 0.000014 0
42 41 6 1 41 0.052014 0.0520 0.000014 0 UDRE Time-Out
48 47 - - 47 0.052329 0.0520 0.000329 0 t-t6>13
54 53 6 1 53 0.092414 0.0924 0.000014 0
60 59 - - 53 0.092729 0.0924 0.000329 0
66 65 6 2 53 0.094297 0.0924
PRC (t ) = PRC n + RRC n (t − t n )
0.001897 0
NOTE:
72 71 6 2 53 0.092696
When IODF in either message is set to 3, then
0.0924 0.006296 0
PRC n − PRC o
78 77 6 2 53 0.108310 0.0924 RRC n 0=
0.015910
t84 =t83 and is not updated to the time of MT6
UDRE n 6 2 53 0.430000 0.0924 0.337600 0 t n − to
90 89 2 0 89 0.052074 0.0520 0.000014 0.000060
96 95 6 0 95 0.054732 0.0520 0.000014 0.002720
102 101 6 0 101 0.061394 0.0520 0.000014 0.009380 RRC Time − Out
108 107 6 0 107 0.122814 0.0924 0.000014 0.030400 ∆ t = t n − t o > I fc
114 113 6 0 113 0.027104 0.0924 0.000014 0.034690
t − t n > 8∆ t
120 119 2 1 119 0.052014 0.0520 0.000014 0
126 125 6 1 125 0.052014 0.0520 0.000014 0 PRC Time − Out
gAGE
132 131 6 1 131 0.052014 0.0520 0.000014 0
t − 119 > I fc + 1
138 137 6 3 119 0.092696 0.0924 0.006296 0
144 143 6 3 119 0.108310 0.0924 0.015910 0
150 149 2 2 149 0.052014 0.0520 0.000014 0 Ifc=66sec
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 78
UPC
research group of Astronomy and Geomatics
Long-Term Corrections (MT25, 24)
• Primarily Correct Ephemeris Errors
– Also removes Slowly Varying Clock
- And discontinuities in Broadcast Ephemeris
– Separate Degradation Factors for Lost
Messages
• For GEO are contained in MT9
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 79
Long-Term Corrections (MT25)
UPC
DIRECTION OF DATA FLOW FROM SATELLITE; MOST SIGNIFICANT BIT (MSB) TRANSMITTED FIRST
research group of Astronomy and Geomatics
250 BITS - 1 SECOND
VELOCITY CODE = 0 IODP
(2 BITS) 24-BITS
δx δy δz af0 δx δy δz af0 S SECOND HALF OF MESSAGE PARITY
ISSUE OF DATA; SEE [1]
PRN MASK NUMBER
6-BIT MESSAGE TYPE IDENTIFIER (= 25)
8-BIT PREAMBLE OF 24 BITS IN 3 CONTIGUOUS BLOCKS
S = SPARE (1-BIT)
δx (t ) δx0 δx0 x xGPS / GLONASS δx
δy (t ) = δy + δy (t − t ) y = y + δy
0 0 0 GPS / GLONASS
δz (t ) δz 0 δz 0
z z GPS / GLONASS
δz
δt (t ) = δa f 0 + δa f 1 (t − t 0 ) + δa fG 00
+ δa fG dt = dt GPS / GLONASS + δt
GLONASS
(MT12)
gAGE
Y = C1 + PRC −ρ * + dt sat + rel − TGD + IONO + TROP
ρ* sat
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 80
UPC GEO Coordinates and clock (MT 9)
DIRECTION OF DATA FLOW FROM SATELLITE; MOST SIGNIFICANT BIT (MSB) TRANSMITTED FIRST
research group of Astronomy and Geomatics
250 BITS - 1 SECOND
. . . .. .. .. aGf1 24-BITS
t0 * XG YG ZG XG YG ZG XG YG Z G aGf0 PARITY
ISSUE OF DATA, SEQUENCING BETWEEN 0 AND 255
6-BIT MESSAGE TYPE IDENTIFIER (= 9)
8-BIT PREAMBLE OF 24 BITS TOTAL IN 3 CONTIGUOUS BLOCKS
*ACCURACY EXPONENT; SEE SECTION 2.5.3 OF [1]
x (t ) xG xG xG
y (t ) = y + y (t − t ) + 1 y (t − t )2
G G 0
2
G 0
z (t ) z G z G
zG
gAGE
dt (t ) = δaGf 0 + δaGf 1 (t − t 0 )
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 81
UPC LONG-TERM DEGRADATION PARAMETER
(GPS/GLONASS/GEO)
research group of Astronomy and Geomatics
MT10
MT10
• GPS/GLONASS
• vcode=1 (MT25, 24)
0 if t0 < t < t0 + Iltc _ v1
ε ltc =
Cltc _ lsb + Cltc _ v1 max(0,t 0 − t,t − t0 − Iltc _ v1 ) otherwise
• vcode=0 (MT25, 24)
t − t
ε ltc = Cltc _ v 0 ltc
I ltc _ v 0
• GEO
0 t0 < t < t 0 + I geo
ε ltc =
Cgeo_ lsb + Cgeo_ v max(0,t 0 − t,t − t0 − I geo) otherwise
gAGE
σ 2i, flt = σ 2UDRE + ε 2 fc + ε 2rrc + ε 2ltc + ε 2er
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 82
UPC
research group of Astronomy and Geomatics
En Route Through NPA Degradation
• For Precision Approach a user is only allowed to miss one of
any particular message. However, the user can still operate in
less stringent phases of flight even if they have missed two or
any particular fast or slow correction messages.
0
εer
Neither fast nor long term corrections
= have time out for precision approach
Cer Otherwise
σ 2i, flt = σ 2UDRE + ε 2 fc + ε 2rrc + ε 2ltc + ε 2er
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 83
Fast Corrections
UPC Ephemeris +
Long Term Corrections MT1, MT2,5,24, MT6,
+ + MT25, MT7, MT12,
research group of Astronomy and Geomatics
UDRE MT9
Clocks +
Degradation Param.
MT10
IONO Corrections
+ MT18
IONO GIVE MT26
+
Degradation Param.
Y = C1 + PRC − ρ * + ∆ t sat + dt sat + rel − TGD + IONO + TROP
IONO
gAGE
σ 2 = σ 2 + σ UIRE + σ air + σ tropo
flt
2 2 2
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 84
UPC
research group of Astronomy and Geomatics Ionospheric Corrections (MT26)
• Only Requiered for Precission Approach
– Grid of Vertical Ionospheric Corrections
– Users Select 3 o 4 IGPs that Surrounding IPP
• 5ºx5º or 10ºx10º for 55º<Lat<55º
• Only 10ºx10º for 55º<|Lat|<85º
• Circular regions for |Lat|>85º
– Vertical Correction and UIVE Interpoled to IPP
– Both Converted to Slant by Obliquity Factor
gAGE
•IGP: Ionospheric Grid Point
•IPP: Ionospheric Pierce Point
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 85
UPC GLOBAL IGP GRID
W180 W140 W100 W60 W20 0 E20 E60 E100 E140
research group of Astronomy and Geomatics
N85
N75
N65
N55
N50
0
S50
0 1 2 3 4 5 6 7 8
S55
S65
gAGE
S75
Figure 17. Predefined Global IGP Grid
S85
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 86
UPC IGP MASK Message (MT18)
250 BITS - 1 SECOND
research group of Astronomy and Geomatics
1-SPARE BIT 24-BITS
201-BIT MASK FIELD PARITY
2-BIT ISSUE OF DATA (IODI)
BAND NUMBER (4 BITS)
NO. OF BANDS (4 BITS)
6-BIT MESSAGE TYPE IDENTIFIER (18)
8-BIT PREAMBLE OF 24 BITS TOTAL IN 3 CONTIGUOUS BLOCKS
IGP=201
(suported)
IGP=125
(suported)
gAGE
IGP=119
(not supported) Band 3 Band 4 Band 5
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 87
UPC IONOSPHERIC DELAYS and BOUNDS (MT26)
D IR E C T I O N O F D A T A F L O W F R O M S A T E L L I T E ; M O S T S IG N IF I C A N T B I T ( M S B ) T R A N S M IT T E D F IR S T
2 5 0 B IT S - 1 S E C O N D
research group of Astronomy and Geomatics
R E P E A T F O R 1 4 M O R E G R ID P O I N T S
2 4 - B IT S
2 3 4 5 6 7 8 9 10 11 12 13 14 15 S P A R IT Y
G I V E I ( 4 B IT S )
IG P V E R T I C A L D E L A Y ( 9 B I T S ) IO D I
B L O C K ID (4 B IT S )
B A N D N U M B E R ( 4 B IT S )
6 -B I T M E S S A G E T Y P E ID E N T I F IE R (= 2 6 )
8 -B I T P R E A M B L E O F 2 4 B IT S T O T A L IN 3 C O N T I G U O U S B L O C K S
S = S P A R E ( 7 B IT S )
GIVEI
(number)
BN=3 &
IGP=178 VD
BI=1 (color)
Pos=10
BN=3
IGP=125
BI=0
Pos=5
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 88
UPC
research group of Astronomy and Geomatics
gAGE ESTB Sep 12th 2002
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 89
UPC IONOSPHERIC PIERCE
POINTS (IPP)
research group of Astronomy and Geomatics
IPPs trajectories
IPP
Slant Delay
Vertical Delay
gAGE
Ionospheric Layer
(350 Km in height)
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 90
UPC
research group of Astronomy and Geomatics
IGPs Selection Rules
• Four Distinct Grid Regions
– First look for Surrounding Square Cell
– Else Seek Surrounding Triangular Cell
– If Neither Available for 5ºx5º look at
10ºx10º
– From 75º to 85º Interpolate Using Virtual
IGPs
– No correction possible if Not Surrounded
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 91
UPC
research group of Astronomy and Geomatics
gAGE |Lat| <= 55
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 92
The selection of Interpolation Grid points
UPC
|Lat| <= 55
research group of Astronomy and Geomatics
Supported IGP
Not Supported
1st 2nd
IPP
3th 4th
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 93
The selection of Interpolation Grid points
UPC
55<|Lat| <= 75
research group of Astronomy and Geomatics
Supported IGP
1st
Not Supported
IPP
2nd
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 94
The selection of Interpolation Grid points
UPC
75<|Lat| <= 85
research group of Astronomy and Geomatics
Linear interpoled IGP
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 95
The selection of Interpolation Grid points
UPC
85<|Lat|
research group of Astronomy and Geomatics
2
3 1
W
E
3
2
3 1
W
gAGE
E
4
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 96
Ionospheric Delay Interpotation
UPC
W2 = (1− x) y
y
W1 = xy
research group of Astronomy and Geomatics
τ v2 τ v1
φ2
λipp − λ1
USER'S IPP
τvpp(φpp, λpp) x=
∆λpp=λpp-λ1
∆λ
φipp −φ1
y=
∆φ
∆φpp=φpp-φ1
φ1 τv3 τv4 x
W3 = (1− x)(1− y) λ
λ2
W4 = x(1− y)
1
MT26
τ vpp (λ pp ,φ pp ) = ∑ Wi ( x pp , y pp )τ vi
4
τ vi
i =1
gAGE
1
−
ICi = −τ spp (λ pp ,φ pp ) = − Fpp ⋅ τ vpp (λ pp ,φ pp )
Re cos E 2
2
F pp = 1 −
Re + h I
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 97
Ionospheric Delay Interpotation
UPC
W2 = y y
W1 = 0
research group of Astronomy and Geomatics
τv1
φ2
λipp − λ1
USER'S IPP
τvpp(φ pp, λ pp) x=
∆λ pp=λpp-λ 1
∆λ
φipp −φ1
∆φ pp=φ pp-φ 1 y=
∆φ
φ1 τv2 τv3 x
W3 =1− x − y λ1 λ2
W4 = x
MT26
τ vpp (λ pp ,φ pp ) = ∑ Wi ( x pp , y pp )τ vi
4
τ vi
i =1
gAGE
1
−
ICi = −τ spp (λ pp ,φ pp ) = − Fpp ⋅ τ vpp (λ pp ,φ pp )
Re cos E 2
2
F pp = 1 −
Re + h I
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 98
Ionospheric Delay Interpotation
UPC
W2 = (1− x) y
2
research group of Astronomy and Geomatics
W3 = (1− x)(1− y) 3 1 W1 = xy
W
φipp−85º
y= 10º
E
4 λipp − λ3
W4 = x(1− y) x= (1− 2y) + y
90º
MT26
τ vpp (λ pp ,φ pp ) = ∑ Wi ( x pp , y pp )τ vi
4
τ vi
i =1
gAGE
1
−
ICi = −τ spp (λ pp ,φ pp ) = − Fpp ⋅ τ vpp (λ pp ,φ pp )
Re cos E 2
2
F pp = 1 −
Re + h I
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 99
Ionospheric Delay Interpotation
UPC
W2 = y
research group of Astronomy and Geomatics
2
3 1 W1 = 0
W3 =1− x − y W
φipp−85º
y= 10º
E
4
λipp − λ3
W4 = x x= (1− 2y) + y
90º
MT26
τ vpp (λ pp ,φ pp ) = ∑ Wi ( x pp , y pp )τ vi
4
τ vi
i =1
gAGE
1
−
ICi = −τ spp (λ pp ,φ pp ) = − Fpp ⋅ τ vpp (λ pp ,φ pp )
Re cos E 2
2
F pp = 1 −
Re + h I
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 100
Degradation of Ionospheric Corrections
UPC
1
2 −2
R cos E
σ 2
=F σ2 2 Fpp = 1 − e
research group of Astronomy and Geomatics
UIRE pp UIVE Re + hI
N
σ 2
UIVE = ∑Wn ( x pp , y pp ) σ n,ionogrid , N = 4 or 3
2
MT10
n =1 Brrc , Cltc _ lsb , Cltc _ v1,
Iltc _ v1, Cltc _ v0 , Iltc _ v0 ,
(σ GIVE + ε iono
)
2
, if RSSiono = 0 ( MT10)
σ 2
ionogrid = Cer , RSSUDRE ,
σ GIVE + ε iono RSSiono = 1 ( MT10)
2 2
, if
Ciono _ ramp , Ciono _ step ,
Iiono , RSSiono
εiono = Ciono _ step floor ( t −iono ) + Ciono _ ramp ( t − tiono )
I
tiono
MT26
gAGE
tiono ,GIVEi
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 101
UPC
research group of Astronomy and Geomatics
SBAS
Performances
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 102
UPC
GNSS Performance Requirements
research group of Astronomy and Geomatics
Flight Accuracy Accuracy Alert Alert Integrity Time Continuity Avail- Associated
Phase (H) 95% (V) 95% Limit (H) Limit (V) to alert ability RNP type(s
ENR 3.7 Km N/A 7400 m N/A 1-10-7/h 5 min. 1-10-4/h 0.99 20 to 10
(2.0 NM) 3700 m to to
1850 m 1-10-8/h 0.99999
TMA 0.74 Km N/A 1850 m N/A 1-10-7/h 15 s 1-10-4/h 0.999 5 to 1
(0.4 NM) to to
1-10-8/h 0.99999
NPA 220 m N/A N/A 1-10-7/h 10 s 1-10-4/h 0.99 0.5 to 0.3
(720 ft) 600 m to to
1-10-8/h 0.99999
APV-I 220 m 20 m 600 m 50 m 1-2x10-7 per 10 s 1-8x10-6 in 0.99 0.3/125
(720 ft) (66 ft) approach any 15 s to
0.99999
APV-II 16.0 m 8.0 m 40 m 20 m 1-2x10-7 per 6s 1-8x10-6 in 0.99 0.03/50
(52 ft) (26 ft) approach any 15 s to
0.99999
CAT-I 16.0 m 6.0 - 4.0 m 40 m 15 -10 m 1-2x10-7 per 6s 1-8x10-6 in 0.99 0.02/40
(52 ft) (20 to 13 ft) approach any 15 s to
0.99999
gAGE
ICAO’s GNSS Standards and Recomendation Practices (SARPS)
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 103
UPC INTEGRITY RISK REQUIREMENTS:
PA: Signal In Space
research group of Astronomy and Geomatics
2x10-7/approach
(150 sec)
Ground System Fault Free Case
1x10-7/approach 1x10-7/approach
(150 sec) (150 sec)
• Failures GPS/GLONASS/GEO Induced by ground segment
• Corruption data thought GEO link measurement data noise and
• Hard, soft and WANet failures algorithmic process (when no
GPS/GLONASS/GEO sat failures, no
ground segment/user equip failures)
gAGE
HPL, VPL
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 104
UPC
PROTECTION LEVELS
To protect the user against misleading information (MI) due to data
corrupted by the noise induced by the measurement and algorithmic
research group of Astronomy and Geomatics
process when the system is in a nominal state.
Protection
Level
True
Error
-Kσ-σ σ Kσ Tail area Probability P(VPE>VPL) < 10-7 /sample
N
VPL = KV ∑s 2
σ 2
σ i2 = σ i2, flt + σ i2,UIRE + σ i2,air + σ i2,tropo
gAGE
Vi i
i =1
GEOMETRY
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 105
UPC
research group of Astronomy and Geomatics North
East
-Kσ -σ σ Kσ
dN + dÈ
2 2
dN − dÈ
2 2
HPL = K h d major = K h
2
+
2
+ d NE
2
VPL = K v d v
• PA: SIS Integrity requirement: 2x10-7 /approach
Kh=6.0, Kv=5.33 (Gaussian distrib.)
- Only 1 indep sample per approach (150s)
- A half of the total integrity allocated to VPL ( 10-7/sample)
- HPL bounding prob. taken as negligible X ~ N (0,1)
and only one dimension is used for HPL ( 10-9/sample)
p ( X > K v ) = 10 −7 ⇒ K v = 5.33
• En Route to NPA: SIS Integ. req. 1x10-7/hour p ( X > K h ) = 10 −9 ⇒ K h = 6.0
Kh= 6.18 (Rayleigh distrib.)
gAGE
- 10 indep samples per hour Y ~ Rayleigh
- A half of the total integrity allocated to HPL p ( Y > K h ) = 5 ⋅10 −9 ⇒ K h = 6.18
- Worst case assumption dmin=dmajor ( 5x10-9/sample)
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 106
UPC Alert Protection
Limits Levels
(HAL,VAL) (HPL,VPL)
research group of Astronomy and Geomatics
NSE: TrueError
(HPE, VPE)
• Each epoch, HPL/VPL are compared with the Alert
Limits (HAL/VAL) defined for the operation mode:
– Hazardously Misleading Information (HMI): NSE> HAL or VAL
INTEGRITY RISK
– Misleading Information (MI): NSE > HPL or VPL
Out-Of-Tolerence cond.
• The system is set unavailable when XPL > XAL
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 107
STANFORD PLOTS
UPC Alarm Epochs
System Unavailable
research group of Astronomy and Geomatics
Hazardously
Misleading
Information
Alert Limit
95th
Percentile
of VPL
Normal
Operation
Region
gAGE
Misleading
95th Percentile
of VPE Alert Limit Information
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 108
UPC
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 109
UPC
research group of Astronomy and Geomatics
ESTB Performances in
Barcelona during 2002
• The ESTB is a full-scale real-time prototype of the EGNOS system,
but it is reduced in size and capabilities.
• Therefore it has to be noted that the results obtained with ESTB will
not be the same as the final EGNOS performances.
gAGE
• EGNOS will benefit from a better infrastructure and a more
developed and robust design.
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 110
gAGE research group of Astronomy and Geomatics UPC
0
1
2
3
4
5
6
7
8
9
2002.01.10
2002.01.17
2002.01.24
2002.01.31
2002.02.07
2002.02.14
2002.02.21
2002.02.28
2002.04.07
2002.03.14
2002.03.21
2002.03.28
2002.04.04
2002.04.11
2002.04.18
2002.04.25
2002.05.02
VPE 95th Percentile
2002.05.09
typically lower than 4 m
2002.05.16
2002.05.23
2002.05.30
2002.06.06
2002.06.13
2002.06.20
2002.06.27
2002.07.04
NPA
APV-I
CAT-I
2002.07.11
APV-II
Operation
2002.07.18
2002.07.25
2002.08.01
2002.08.08
RTCA/DO-229A
2002.08.15
2002.08.22
2002.08.29
April 16th
2002.09.05
ESTB Update
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002.
2002.09.12
2002.09.19
2002.09.26
16 m
16 m
220 m
220 m
2002.10.03
2002.10.10
2002.10.17
2002.10.24
95th HPE and VPE percentiles
2002.10.31
2002.11.07
Horizontal Accuracy 95%
2002.11.14
RTCA/DO-229B
2002.11.21
2002.11.28
2002.12.05
2002.12.12
2002.12.19
8m
N/A
20 m
6-4 m
VPE
HPE
Vertical Accuracy 95%
111
gAGE research group of Astronomy and Geomatics UPC
0
5
10
15
20
25
30
35
2002.01.10
2002.01.17
2002.01.24
2002.01.31
2002.02.07
2002.02.14
2002.02.21
2002.02.28
2002.04.07
2002.03.14
2002.03.21
2002.03.28
2002.04.04
2002.04.11
2002.04.18
2002.04.25
VPL 95th Percentile
2002.05.02
2002.05.09
typically lower than 20 m
2002.05.16
2002.05.23
2002.05.30
2002.06.06
2002.06.13
2002.06.20
2002.06.27
2002.07.04
NPA
APV-I
CAT-I
2002.07.11
APV-II
Operation
2002.07.18
2002.07.25
2002.08.01
2002.08.08
RTCA/DO-229A
2002.08.15
2002.08.22
2002.08.29
April 16th
2002.09.05
ESTB Update
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002.
2002.09.12
2002.09.19
2002.09.26
40 m
40 m
2002.10.03
556 m
556 m
2002.10.10
2002.10.17
95th HPL and VPL percentiles
2002.10.24
2002.10.31
Horizontal Alarm Limit
2002.11.07
2002.11.14
RTCA/DO-229B
2002.11.21
2002.11.28
2002.12.05
2002.12.12
2002.12.19
N/A
12 m
20 m
50 m
VPL
HPL
Vertical Alarm Limit
112
gAGE research group of Astronomy and Geomatics UPC
50
55
60
65
70
75
80
85
90
95
100
2002.01.10
2002.01.17
2002.01.24
2002.01.31
2002.02.07
2002.02.14
2002.02.21
2002.02.28
2002.04.07
2002.03.14
2002.03.21
2002.03.28
2002.04.04
2002.04.11
2002.04.18
2002.04.25
2002.05.02
availability > 99%
Several times APVII
2002.05.09
2002.05.16
2002.05.23
2002.05.30
2002.06.06
2002.06.13
2002.06.20
2002.06.27
2002.07.04
2002.07.11
2002.07.18
2002.07.25
2002.08.01
2002.08.08
RTCA/DO-229A
2002.08.15
2002.08.22
Availability
2002.08.29
April 16th
2002.09.05
2002.09.12
ESTB Update
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002.
2002.09.19
2002.09.26
2002.10.03
2002.10.10
2002.10.17
2002.10.24
2002.10.31
2002.11.07
2002.11.14
2002.11.21
RTCA/DO-229B
2002.11.28
2002.12.05
2002.12.12
2002.12.19
H-APV
V-APVI
V-CATI
V-APVII
113
gAGE research group of Astronomy and Geomatics UPC
90
91
92
93
94
95
96
97
98
99
100
101
2002.01.10
2002.01.17
2002.01.24
2002.01.31
2002.02.07
2002.02.14
2002.02.21
2002.02.28
2002.04.07
2002.03.14
2002.03.21
2002.03.28
2002.04.04
2002.04.11
2002.04.18
2002.04.25
availability > 99%
2002.05.02
Several times APVII
2002.05.09
2002.05.16
2002.05.23
2002.05.30
2002.06.06
2002.06.13
2002.06.20
2002.06.27
2002.07.04
2002.07.11
2002.07.18
2002.07.25
2002.08.01
2002.08.08
RTCA/DO-229A
2002.08.15
2002.08.22
2002.08.29
April 16th
2002.09.05
2002.09.12
ESTB Update
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002.
2002.09.19
2002.09.26
2002.10.03
Availability (zoom)
2002.10.10
2002.10.17
2002.10.24
2002.10.31
2002.11.07
2002.11.14
2002.11.21
RTCA/DO-229B
2002.11.28
2002.12.05
2002.12.12
2002.12.19
H-APV
V-APVI
114
V-APVII
gAGE research group of Astronomy and Geomatics UPC
120
100
80
60
40
20
0
2002.01.10
2002.01.17
April 16th
2002.01.24
ESTB Update
2002.01.31
2002.02.07
2002.02.14
2002.02.21
2002.02.28
2002.04.07
2002.03.14
2002.03.21
2002.03.28
September 12th. See
April 16th, except for
2002.04.04
analysis in example 8.
2002.04.11
Basically NO LOIs after
2002.04.18
2002.04.25
2002.05.02
2002.05.09
2002.05.16
2002.05.23
2002.05.30
2002.06.06
2002.06.13
2002.06.20
2002.06.27
2002.07.04
2002.07.11
2002.07.18
2002.07.25
2002.08.01
2002.08.08
2002.08.15
2002.08.22
2002.08.29
2002.09.05
2002.09.12
2002.09.19
LOI events
2002.09.26
2002.10.03
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002.
2002.10.10
2002.10.17
2002.10.24
2002.10.31
2002.11.07
2002.11.14
2002.11.21
2002.11.28
2002.12.05
2002.12.12
2002.12.19
V-APVI
115
V-CAT I
V-APVII
H-APVII
UPC
research group of Astronomy and Geomatics
EXAMPLE 3 :
Large Protection Level Values
(ESTB January 10th 2002)
4 satellites used in the computations
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 116
UPC 36966 sec of day (UTC)
36967 sec of day (UTC)
research group of Astronomy and Geomatics
Few number
of satellites and
bad geometry
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 117
UPC
Which satellites are being used?
research group of Astronomy and Geomatics
36966 sec of day (UTC)
N. Sat. used PRN UDRE
36967 sec of day (UTC)
382576 11 4 : 30 5 : 21 - : 7 11 : 14 12 : 26 10 : 5 5 : 9 10 : 29 12 : 6 - : 4 - : 120 -
382577 11 4 : 30 5 : 21 - : 7 11 : 14 12 : 26 10 : 5 5 : 9 10 : 29 12 : 6 - : 4 - : 120 -
382578 11 4 : 30 5 : 21 - : 7 11 : 14 12 : 26 10 : 5 5 : 9 10 : 29 12 : 6 - : 4 - : 120 -
382579 11 4 : 30 5 : 21 - : 7 11 : 14 12 : 26 10 : 5 number
5 Few : 9 10 : 29 12 : 6 - : 4 - : 120 -
UDRE
382580 11 5 : 30 5 : 21 - : 7 10 : 14 12 : 26 10 : 5 of satellites and 29
5 : 9 10 : 12 : 6 - : 4 - : 120 -
382581 11 5 : 30 5 : 21 - : 7 10 : 14 12 : 26 10 : 5 5 geometry
bad : 9 10 : 29 12 : 6 - : 4 - : 120 -
382582 11 5 : 30 5 : 21 - : 7 10 : 14 12 : 26 10 : 5 5 : 9 10 : 29 12 : 6 - : 4 - : 120 -
382583 11 5 : 30 5 : 21 - : 7 10 : 14 12 : 26 10 : 5 5 : 9 10 : 29 12 : 6 - : 4 - : 120 -
382584 11 5 : 30 5 : 21 - : 7 10 : 14 12 : 26 10 : 5 5 : 9 10 : 29 12 : 6 - : 4 - : 120 -
N. Sat. in view
The MOPS (RTCA Do 229A) 2.1.1.5.2, establish the satellites
deselecting for:
-UDRE=14 (not monitored)
gAGE
and
No ephemeris Used for nav. -UDRE=15 (don’t use)
No differential Corr. UDRE>10 2.1.4.7.1: In addition, for Precision Approach:
UDRE< 11.
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 118
UPC
research group of Astronomy and Geomatics
EXAMPLE 4 :
Fast Correction degradation
(ESTB January 10th 2002)
4 or 5 satellites used in the computations
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 119
(t − tu + tlat )
2 a= 5.8mm / s 2 ; tlat = 7 s
UPC
research group of Astronomy and Geomatics
ε fc = a 2 t − tu = t − t fc ≤ 5 s (tipically )
ε fc
∆UDRE
10 → 9
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 120
UPC
research group of Astronomy and Geomatics
σ 2i, flt = σ 2UDRE + ε 2 fc + ε 2rrc + ε 2ltc + ε 2er
∆nsatellites ∆UDRE
4→5 11 → 10
∆UDRE
gAGE
10 → 9
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 121
UPC
research group of Astronomy and Geomatics
EXAMPLE 5 :
Periods without Nav. Sol.
(ESTB, February 14th 2002)
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 122
Sec of W eek Message Type PRN of Satellites in use Analysis of Feb 14th
UPC
413846 MT02 11 14 20 28 29 31
413847 MT03 11 14 20 28 29 31
research group of Astronomy and Geomatics
413848 MT04 11 14 20 28 29 31
413849 MT25 11 14 20 28 29 31
413850 MT00 11 14 20 28 29 31
413851 MT26 BN4 BI1 11 14 20 28 29 31
12 sec
413852 MT26 BN4 BI1 11 14 20 28 29 31
413853 MT26 BN4 BI1 11 14 20 28 29 31
413854 MT26 BN4 BI1 11 14 20 28 29 31
413855 MT26 BN4 BI2 11 14 20 28 29 31
SIS anomaly that
413856 MT26 BN4 BI2 11 14 20 28 29 31
should be solved
21 sec
413857 MT26 BN4 BI2 11 14 20 28 29 31
413858 MT26 BN4 BI2 11 14 20 28 29 31 with MT6 broad.
413859 MT26 BN4 BI3 20 28 29 31
413860 MT26 BN4 BI3 31
413861 MT26 BN4 BI3
413862 MT26 BN4 BI3
• MT26 repetitions (alarm condition).
413863 MT26 BN4 BI4
413864 MT26 BN4 BI4 • FC updated after 21 seconds.
413865 MT26 BN4 BI4 The satellites are deselected after
413866 MT26 BN4 BI1 12sec, due to the UDRE Time-Out.
gAGE
413867 MT02
413868 MT03 11 14
413869 MT04 11 14 20 28 29
413870 MT00 11 14 20 28 29 31
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 123
UPC
research group of Astronomy and Geomatics
EXAMPLE 6 :
Analysis of PRC (PRN10)
Large Values
(ESTB February 14th 2002)
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 124
UPC
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 125
UPC
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 126
UPC
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 127
UPC
research group of Astronomy and Geomatics
EXAMPLE 7 :
LOI when High PRC for PRN10
(ESTB February 14th 2002)
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 128
Analysis of Feb 14th2002: LOI when High PRC for PRN10
UPC
research group of Astronomy and Geomatics
The large PRC that jumps
at steps of 90s, induces
periodic peaks every 90s
to the navigation solution.
SIS Anomaly
It produces LOI conditions.
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 129
UPC
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 130
UPC
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 131
UPC
research group of Astronomy and Geomatics
EXAMPLE 8 :
LOIs due to wrong ionospheric
corrections
(ESTB September 12th 2002)
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 132
UPC1 and UPC2 16Km baseline
UPC
UPC1 UPC2
research group of Astronomy and Geomatics
HOR
MI=42 MI=49
VERT
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 133
UPC
research group of Astronomy and Geomatics Sep 12th 2002 MI analysis
HPE and HPL in UPC1
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 134
UPC
research group of Astronomy and Geomatics Sep 12th 2002 MI analysis
HPE and HPL in UPC2
gAGE
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UPC
research group of Astronomy and Geomatics Sep 12th 2002 MI analysis
Ionospheric Correction
PRN 17
Other
Satellites
gAGE
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UPC
research group of Astronomy and Geomatics Sep 12th 2002 MI analysis
UIRE
PRN 17
Other
Satellites
gAGE
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UPC Sep 12th 2002 MI analysis
ELEVATION
research group of Astronomy and Geomatics
Other
Satellites
gAGE
PRN 17
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 138
UPC Sep 12th 2002 MI analysis
418000
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 139
UPC Sep 12th 2002 MI analysis
418000
research group of Astronomy and Geomatics
gAGE
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UPC
research group of Astronomy and Geomatics
PART III
EGNOS and Civil Aviation
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 141
UPC
research group of Astronomy and Geomatics Civil Aviation Navigation
• VFR : Visual Flight Rules
Visibility better than 5 Km – 8 Km
• IFR : Instrumental Flight Rules
Radionavigation Aids
gAGE
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UPC Radionavigation Aids
Non Directional Beacon (NDB)
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 143
UPC Radionavigation Aids
VHF Omnidirectional Ranger (VOR)
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 144
UPC Radionavigation Aids
Distance Measuring Equipement (DME)
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 145
UPC Radionavigation Aids
Instrumental Landing System (ILS)
research group of Astronomy and Geomatics
LOCALIZER
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 146
UPC Radionavigation Aids
Instrumental Landing System (ILS)
research group of Astronomy and Geomatics
GLIDE SLOPE
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 147
UPC Radionavigation Aids
Instrumental Landing System (ILS)
research group of Astronomy and Geomatics
gAGE
Horizontal and Vertical guidance
Horizontal and Vertical guidance
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 148
UPC Radionavigation Aids
Radar Vectoring
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 149
UPC Phases of flight
Terminal En route Terminal
research group of Astronomy and Geomatics
Manouvering Area Manouvering Area
(TMA) (TMA)
Final App Taxi Missed
Taxi Take off Departure Cruise Arrival Approach
landing Approach
VOR
VOR
DME
DME Non Precision ILS Precision
NDB
gAGE
NDB 3D
Radar Vectoring
2D
2D
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 150
UPC
research group of Astronomy and Geomatics
gAGE IFR Cruise
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 151
UPC
research group of Astronomy and Geomatics
gAGE IFR Arrivals
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 152
UPC
research group of Astronomy and Geomatics
gAGE IFR Approach
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 153
UPC
research group of Astronomy and Geomatics
gAGE Avionics
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 154
UPC
research group of Astronomy and Geomatics
gAGE Avionics
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 155
UPC
research group of Astronomy and Geomatics RNAV concept
• RNAV = Area Navigation
Navigation using flight tracks joining ANY
two points without the need for the overfly
of specific ground facilities.
gAGE
Basic RNAV (B-RNAV) = +/- 5NM accuracy
Precision RNAV (P-RNAV) = +/- 1NM accuracy
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 156
UPC
research group of Astronomy and Geomatics RNAV concept
• RNAV = Area Navigation
Navigation using flight tracks joining ANY
two points without the need for the overfly
of specific ground facilities.
• More flexibility
• Less fuel consumption
• Delay reduction (bottle necks)
• Noise reduction
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 157
UPC
research group of Astronomy and Geomatics RNAV concept
RNAV (Area Navigation)
– VOR/DME
– DME/DME
– INS
– LORAN C
– GPS + RAIM
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 158
UPC
research group of Astronomy and Geomatics RNAV concept
RNAV (Area Navigation)
– VOR/DME
– DME/DME
– INS
– LORAN C
– GPS + RAIM
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 159
UPC
research group of Astronomy and Geomatics RNAV concept
RNAV (Area Navigation)
– VOR/DME
– DME/DME
– INS
– LORAN C
– GPS + RAIM 415427N
022343E
410315N
002635E
gAGE
403519N
011456E
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 160
UPC RNAV application (spain)
B-RNAV P-RNAV free
research group of Astronomy and Geomatics
B-RNAV
routes routes routes?
FL 245
Optional B-RNAV
routes FL 150
Optional 4D RNAV?
Conventional Conventional
B-RNAV
routes routes
routes
TMA P-RNAV
Exceptional Optional P-RNAV procedures?
B-RNAV procedures procedures Vertical
Guidance
Conventional Conventional
procedures procedures
gAGE
4D RNAV?
1998 Mar 2003 2005
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 161
UPC RNAV application (spain)
B-RNAV P-RNAV free
research group of Astronomy and Geomatics
B-RNAV
routes routes routes?
FL 245
DME
Optional B-RNAV
routes FL DME/DME
150
VOR/DME Optional 4D RNAV?
Conventional Conventional
B-RNAV
routes routes
routes
TMA P-RNAV
Exceptional Optional P-RNAV procedures?
procedures
Galileo
B-RNAV procedures Vertical
EGNOS Guidance
Conventional
GPS Conventional
procedures procedures
gAGE
4D RNAV?
1998 Mar 2003 2005
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 162
UPC Vertical Guidance
Nowadays RNAV procedures are only 2D
research group of Astronomy and Geomatics
For precision approaches Vertical Guidance is also needed
Decision Height Visibility
CAT - I 200 ft (60m) > 800 m
CAT - II 100 ft (30m) > 400 m
CAT - III 100 ft - 0 ft * > 400 m - 0 m *
gAGE
* Variable in function of aircraft , crew, airport facilities,... certification
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 163
UPC
research group of Astronomy and Geomatics Vertical Guidance
EGNOS is designed to meet P-RNAV with
vertical guidance (APV)
ILS EGNOS
Very precise approaches: CAT-I performnances
CATI, CATII, CATIII
Straight approaches Curved approaches
Local coverage Global coverage with constant
accuracy
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 164
Example: Nice approaches
UPC
research group of Astronomy and Geomatics
gAGE
See [3]: Approaching Nice with the EGNOS System Test Bed. Satellite Navigation and Positioning world show, NavSat 2001
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 165
Benefits of EGNOS
UPC
in Civil Aviation
research group of Astronomy and Geomatics
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 166
UPC Bibliography
1. J. Ventura-Travesset, P. Michael and L. Gautier, 2001.
research group of Astronomy and Geomatics
Architecture, Mission and signal processing aspects of the
EGNOS System: the first European implementation of GNSS.
http://esamultimedia.esa.int/docs/egnos/estb/Publications.
2. Todd Walter, 1999. WAAS MOPS: Practical Examples. ION
National Technical Meeting Proceedings, Sant Diego, California,
USA. http://waas.stanford.edu/.
3. S. Soley, E. Breeuwer, R. Farnworth, J.P. Dupont, Y. Coutier,
2001, Approaching Nice with the EGNOS System Test Bed.
Satellite Navigation and Positioning world show, NavSat 2001.
http://www.eurocontrol.fr/projects/sbas.
4. Minimum Operational Performances Standards for Global
Positioning System / Wide Area Airborne Equipment. RTCA/Doc
229A, June 1998.
5. M. Hernández-Pajares, J.M. Juan and J. Sanz, 2002. GPS Data
processing: Code and Phase. Algorithms, Techniques and
Recipes. http://gage1.upc.es (in Spanish and English)
gAGE
6. M. Hernández-Pajares, J.M. Juan and J. Sanz, X. Prats, J. Baeta.
Basic Research Utilities for SBAS (BRUS). V Geomatics Week.
Barcelona, 2003.
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 167
UPC
Acknowledgments
research group of Astronomy and Geomatics
We acknowledge to EUROCONTROL for providing the ESTB
data sets used in the ESTB performance examples.
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 168
UPC
research group of Astronomy and Geomatics
That’s all,
Thank you
for your attention!
gAGE
Manuel Hernández-Pajares, J. Miguel Juan, Jaume Sanz, Xavier Prats, February 2002. 169
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