IEEE AESS Houston Modified

8/14/2019 IEEE AESS Houston Modified

1/61

Global Navigation Satellite System (GNSS)- A vast System of Systems

Dr. S. Pal

Outstanding Scientist/Program Director,

Satellite Navigation Program

Chairman, GAGAN PMB

Deputy Director,

ISRO Satellite CentreBangalore


2/61

HISTORY OF NAVIGATION

Navigation is the science of charting ones ownroute from point A to point B with respect to

known references both in spatial as well as in

temporal domain

Identifying and remembering objects and land markslike rocks, trees, rivers, marking on trees or leaving

stones/flags and looking at Sun and Moon, as points

of reference were the techniques and navigational

aids that the early man used to find his way in

jungles, deserts, mountains etc. Perhaps the time

reference was day/night or even could be seasons.

The situation changed drastically when man started

long voyages on oceans.


3/61

HISTORY OF NAVIGATION

Phoenicians , Vikings and Greek were undertaking sea voyages andhad navigation skills even 3000 years back. Phoenicians claimed tohave circumnavigated Africa from Red sea, sailing via the Cape ofGood Hope.

Burning fire on mountain tops were used as light houses. Thelegendary Light House of Alexandria was an example.

Navigation word has perhaps its origin in Naoka- Nav boat + Gati-

velocity , in Sanskrit. Not much is written in the modern history about Navigation activities

in Asia-Pacific region. Chinese, Arabs etc., had under taken lot of seavoyages.

In Mohanjadaro ruins (Indian sub continent ) one clay tablet was foundwhich depicted a boat.

Sindhu or Indus valley civilization ruins ( parts of Pakistan, Gujarat ,Harayana ) do show that perhaps a successful business withRomans, Babylonians and Sumerian civilizations.

Out of 18 Tamil Sidhas, Sidha Bhoganathar went to China via searoute (even he is supposed to have designed an aeroplane) and livedin China as Lao-tzu, spread Taosim. He is attributed to have greatnavigational skills.


4/61

History of NavigationThe great sanskrit scholar Kalidas (4th century A.D) was the first one toimagine above land navigation. In his famous Sanskrit Kavya`Meghdoot , Kalidass Yaksha instructs `Megha ,how to navigate fromRamagiri to Alkapuri. He used complete Bio-Sphere as NavigationalControl Points.

Soar up high and head North.Lift yourselves a little higher westward and keep moving. Relax for a while onthe top ofMount Amrakuta, whose burning woods you will have helped soak

As you lighten you will pick up speed and reach the rocky Vindhya Range.

.The wind there will be too weak to hoist you.

.The chataka birds will follow as you travel shedding rain catching the headyscent of flowers and charred wood charred summer fires

..when you reach Dashran, you will see garden hedges white with Ketakiflowers

..In the royal city of Vidisha you will be able to sip the sweet waters of theVetravati River. Go ahead and rest for a white on the low peaks ofNichais.

.Dont forget to detour a little and checkout the view ofUjjayinis white

mansions and savor..Along the way fill yourselves up at the nirvindhya River.

When you reach Awanti look forVishala, a city made in heaven.

There the cool morning breeze, fragrant from lotus blossoms on theShipra River,,,,,,,,,,,,

.Nurse the lotus flowers in the Manasa Lake with your water

There to the north ofKuberas estate is our house with a large rainbowlike gate and a Mandartree which is just like a.


5/61

Archeological site at Lothal (Gujarat ,India) has got remains of

a port which indicated more than 4500 years back India had

advanced sea transport system. The dock is almost of the

same size as that of Visakhapatnam, modern port.


6/61

Cross-staff

Astrolable

Traverse board

Position

ingduring

14-16c

entury

Sextant

Compass Rose

Radio Communication ( I & II World War)

Radar (Robert Watson Watt -1935)

Chronometer

George Harrison, 1764 A.D

Position

ingdur

ing17-20c

entury

Dead reckoning tools

Compass

Latitude

Speed

Direction

Longitud

e

RadioR

anging

VOR

LORAN

LandBasedR

adio

ositioning

TRANSITGPS

SpaceBa

sed

Positio

ning...

..

Egyptian Groma

20th Century


7/61

FIRST RADIO-POSITIONG SYSTEM FOR

MARITIME APPLICATIONS

SERVICE FROM 30 CHAINS FOR WIDE

COVERAGE

PRINCIPLE OF RANGING FOR POSITION-FIX:

RADIO-PULSE TRANSMISSION FROM MASTER AND

SECONDARY STATIONS (OVER A GLOBAL NETWORK)

RECIEVER GETS BOTH PULSES AND TIME

DIFFERENCES (TD) FOR EACH PAIR OF MASTER-SECONDARY STATIONS IS COMPUTED

LOCUS OF POINTS HAVING THE SAME TD FROM A

SPECIFIC MASTER-SECONDARY PAIR IS A CURVED

LINE OF POSITION (LOP).

POSITION DETERMINED BY INTERSECTION OF 2 LOPs

TD IS USED WITH MAPS TO ESTIMATE LAT/LONG

PHASE MEASUREMENTS IMPROVES PRECISION

LORAN OPERATING RANGE : 90-110 KHZ

LIMITED COVERAGE: ~1000km RANGE

OBSTRUCTION/INTERFERENCE FROM GROUND

FEATURES

REFLECTION BY IONOSPHERE

POSITION ACCURACY: ~460m AT BEST

LAND BASED LORAN -C (LONG RANGE NAVIGATION)

x2,y2x1,y1

x3,y3x,y

21

2

1

2

1

2

2

2

2 )()()()( dyyxxyyxx =++

31

2

1

2

1

2

3

2

3 )()()()( dyyxxyyxx =++


8/61

SATELLITE

NAVIGATION &

POSITION SYSTEMS

SECOR (Sequential Collation of Range)

SECOR was a U.S army satellite navigation and positioning system. Thirteen satellites

were launched between 1964 and 1969.

TIMATION

Developed in 1972 by the Naval Research Laboratory (NRL),TIMATION satellites were intended to provide time and frequencytransfer. The third satellite acted as a GPS technology

demonstrator.

TSIKADA

Russian four satellite civil navigation system

TSYKLON

First navigation satellite launched by soviet union in late 1967.

The satellite is based on doppler technique similar to

TRANSIT system.

TRANSIT

Operated in 100 MHz and 400 MHz frequency bands and allowed the user to determine

their position by measuring the Doppler shift of a radio signal transmitted bythe satellite.

When man moves from one place to another 3D positioning (latitude,

longitude & height) are required.

GPS (1978) &

GLONASS

SPUTNIK

First artificial Satellite launched from Russia. Operated using

Doppler frequency shift to obtain position.


9/61

Navigation Satellites

2)uzs(z2)uys(y2)uxs(x0t ++=+ = ,timed

op

pl

er

Zenith

Elevation

Horizon

TRANSIT (US Navy satellite developed by John Hokins, AppliedPhysics Laboratory , 1960-1996). Based on doppler shift

measurements of a 400 MHz tone. TIMATION ( TIMe/navigATION) Programme. - 2 satellites (1967

& 1969) also called NCST ( Navy Centre for Space Technology)satellites carried quartz oscillator which were regularly updatedby master clocks.

NAVSTAR ( NAVigation Satellite Timing and Ranging) of US Air

force PROJECT621. used pseudorandom noise ranging signals. UnderTIMATION Program two more satellites viz., NTS-I( Navigation Technology Satellite) and NTS-II were launched in1974 and 1977 and carried Rubidium and cesium Atomic clocks.

In 1978, US Govt. Decided to bring all the above technologiesunder one head and made a joint program office under which

umbrella, GPS satellites were developed and first block 1satellites were launched during 1978-1985 and second blockduring 1989 to 1990. GPS constellation was completed by 1995.


10/61

SATELLITE CONSTELLATION

DESIGN PARAMETER

ORBIT CHARACTERISTICS

ORBITAL HEIGHT >= 20,000

KM

LONGER VISIBILITY

ORBITAL PERIOD

PERTURBATIONS(MINIMUM)

SOLAR RADIATION PRESSURE

(IMPACTS ECCENTRICITY)LUNI SOLAR FORCES (IMPACTS

INCLINATION)

COMMUNICATION ANTENNA

ISO FLUX (MORE THAN EARTH DISC)

FREQUENCY - L BAND

MINIMUM BACKGROUND THERMAL

NOISE

MINIMUM PATHLOSS

MINIMAL IONOSPHERIC GROUP DELAY

MINIMAL ATTENUATION

3,

2

an

nT

==

)Re

Re(1cos

alt+

=


11/61

SATELLITE CONSTELLATION DESIGN PARAMETER

1. ORBIT CHARACTERISTICS

ORBITAL HEIGHT >= 20,000 KM

LONGER VISIBILITY

ORBITAL PERIOD

PERTURBATIONS(MINIMUM)

SOLAR RADIATION PRESSURE

(IMPACTS ECCENTRICITY)

LUNI SOLAR FORCES (IMPACTSINCLINATION)

PLANES

LAUNCH CONSIDERATIONS

SPARE REQUIREMENT

INCLINATION

GLOBAL/HIGH LATITUDE COVERAGE

2. COMMUNICATION

ANTENNA ISO FLUX (MORE THAN EARTH DISC)

FREQUENCY - L BAND

MINIMUM BACKGROUND THERMAL NOISE

MINIMUM PATHLOSS

MINIMAL IONOSPHERIC GROUP DELAY

MINIMAL ATTENUATION

MODULATION - CDMA/FDMA

MODULATION OF BPSK & SPREAD

SPECTRUM

CDMA- SINGLE FREQUENCY FORMULTIPLE SATELLITE DOWNLINK

FDMA- MULTIPLE FREQUENCY JAMMING

DIFFICULT

3,

2

an

nT

==

)Re

Re(1cos

alt+

=


12/61

REALTIME POSITION FIXING USING SATELLITES

1

2

3

4

(X,Y,Z, b)

(Un Known)

(XI,YI,ZI) REAL-TIME 3D POSITION FIXING:

1-WAY RANGING

ATOMIC CLOCK FOR PRECISERANGING

MIN OF 4 SATELLITES VISIBLE

ANYTIME

WORLD-WIDE TIME SYNCHRONISATION

2-FREQUENCY FOR IONOSPHERIC

CORRECTIONS SIMPLE USER-END EQUIPMENT

ACCURACY: FEW METRES

bZZYYXXP

bZZYYXXP

bZZYYXXP

bZZYYXXP

+++=

+++=

+++=

+++=

2

4

2

4

2

44

2

3

2

3

2

33

2

2

2

2

2

22

2

1

2

1

2

11

)()()()()()(

)()()(

)()()(

SOURCES OF ERROR

System Noise ~ 2m

Ephemeris ~ 5mSatellite clock ~ 1m

Receiver clock ~ 2m

Multi-path ~ 0.5m

Troposphere delay ~ 1m

Ionosphere delay ~10m

Ionospheric delay

Tropospheric delay


13/61

ELEMENTS OF A SATELLITE POSITION FIXING

)]nm

((sinsin)mn

P

n

re

R

2n

n

1mnmJ(sin

nP

n

re

R

2nnJ[1

r

V

==

+

== )

MEASUREMENT (UHF, S-BAND, LASER)

MODELLING (Geo-Potential, Drag, SRP,

Luni-Solar) ESTIMATION (Least-Square, Kalman filter)

rrd

drag vvm

ACP )(

2

1=

uvm

A

PPdrag ))1( +=

)](2sinsinsin)sin(2sin[cos8

3 22

1jjjjj

j

iiiiydt

di+=

=

LEO (m/s2)

Atm drag 6*10-5

SRP 4.7*10-6

Sun 5.6*10-7

Moon 1.2*10-6


14/61

DILUTION OF PRECISION AND IMPACT ON

POSITION ACCURACY

Range

1,4i

1i

uziz

i

uyiy

i

uxixAwhere,

1ATATraceDOP

==

=

=

1 2

2

1

DOP 1/volume

POSITION ERROR IS A FUNCTION

OF:

DILUTION OF PRECISION

MEASUREMENT ACCURACY

MEASUREMENT ERROR


15/61

SATELLITE POSITIONING SYSTEM SEGMENTS


16/61

GPS, GLONASS & GALILEO - Configuration

Constellation GPS GLONASS GALILEOTotal Satellites 24+3 24 (4 Opr) 27+3

Orbital Period 12 hrs 11hrs 15min 14Hrs 22minOrbital planes 6 3 3

Orbital height (km) 20200 19100 23616

Sat. In each plane 4 8 10

Inclination 55 deg 64.8 deg 56 deg

Plane Separation 60 deg 120 deg 120 deg

Frequency 1575.42MHz1227.6MHz

1246 - 1257 MHz1602 - 1616 MHz

1164 - 1300 MHz1559 - 1591 MHz

Modulation CDMA FDMA CDMA


17/61

GLOBAL POSITIONING SYSTEM GPS is first one way (passive) ranging satellite

system The principal objective of the DOD is to offer USmilitary accurate estimates of Position, Velocity andTime (PVT) for a high dynamics platform (P 10m,velocity error 0.1 m/s and time error 100 ns all inrms)

Signal should have a measure of resistance tojamming and interference. That is why transmissionof signals on the same carrier is being done usingCDMA.

Provision to deny the use to US adversaries and atthe same time enhancing the accuracy over ageographical location on a limited time. (This wasdone in the Iraq war keeping high accuracy over aperiod of 2Hrs).


18/61

Planned modernization of the GPS signalsCurrent frequency Plan Planned Frequency Capabilities

(additional)

------------------------------------------------------------------------------------------------------------------

Carrier frequencies Additional civilian frequency 6 dB higher powerrelative to L1

L1 : 1575.42 MHz L5 : 1176.45 MHz 20 MHz broadcastbandwidth

L2 : 1227.60 MHz (safety-of-life service frequency Improved signal cross

L2 C protection (ARNS-band)) correlation

Code frequencies ME code (L1/L2) M-code designed to

(pseudorandom) enhance system security

P-code: 10.23 MHZ (on L1/L2) to improve anti-jamming

Code frequencies (gold code) Dual freq. ionosphere

C/A-code:1.023MHz(onL1) C/A code on L2(1127.60MHz) correction (improved)

UERE and betteraccuracy)

Navigation message Ephemeris, SV clock parameters On L1, L2 and L5

ionospheric parameters, SV health

GLONASS


19/61

GLONASSGLONASS

(GLObalnaya NAvigatsionnaya Sputnikovaya Sistema)(GLObalnaya NAvigatsionnaya Sputnikovaya Sistema)

Parallel constellation to GPS

Constellation was fully operational only in 1995 98 andfailed satellites were not replaced later on.

As of April 2006, 15 operational satellites available.

Minimum satellites required are 18 which will beavailable by 2007 end.

GLONASS is credited for providing precise universaltime coordinated transfer with better position accuracies

India will be helping in completion of the full constellationby launching M series and manufacturing K series

Note: Use of GLONASS in addition to GPS provides increasedsatellite signal observations, spatial distribution of visiblesatellites, reduced horizontal and vertical DOP and decreased

occupational times.


20/61

GALILEO ServicesGALILEO Services (Planned)(Planned) Galileo envisages the provision of large variety of services based on

needs and market analysis.

satellite only, locally assisted, EGNOS Combined services

Galileo satellite only services: Open services,Safety of life, Commercial, Public regulated,

Search & Rescue

Open service Position and Timing Performance of : H : 15 meters, V : 35 meters (95% Single frequency) H : 4 meters, V : 8 meters (95% Dual frequency)

Integrity: No, Timing Accuracy: 39 ns (Three frequencies)

Safety of Life: Availability : 99.8%, Position accuracy : 4-6 m (95% Dual Frequency) Integrity: Yes, Certification/Liability: Yes


21/61

GALILEO ServicesGALILEO Services (Planned)(Planned) Combined Services:

Availability : 99.8% (Global), Position Accuracy : 95% (Dual frequency) Integrity Value Added Services

Public Regulated Services: Availability : 99%, Position Accuracy: H-6.5m, V-12m(95% Dual

frequency), Timing Accurcy : 100 ns, Integrity: Yes

Search and Rescue Services: Capacity:150 beacons Galileo Locally Assisted Services:

Local Precision Navigation Service (1m, TTA 1s), Local High Precision Navigation Service (Position error < 10 cm) Local Assisted Navigation Services Local Augmented Availability Services (Pseudolite services)

Note: Total Project cost is 2.3 billion Euros and market as projected is10 billion Euros/Year and Growth rate is 25% and will reach 300

billion Euros in 2020 with 3 billion receivers in market.


22/61

GPS GPSGPSGALILEO GLONASS GLONASS

1164.000MHz

1

188.000MHz

1

212.000MHz

1

215.000MHz

1

215.600MHz

1

260.000MHz

1

237.827MHz

1

239.600MHz

1

261.610MHz

GALILEO

1

300.000MHz

1

559.000MHz

1

592.952MHz

1

610.000MHz

1

620.610MHz

1

626.500MHz

1

587.420MHz

1

563.420MHz

GALILEO

5

010.000MHz

5

030.000MHz

Radioastronomy

1610.6 1613.6 MHz

GPS GLONASS & GALILEO


23/61

GPS, GLONASS & GALILEO

Frequency Plans


24/61

Thankfully borrowed from ICG Bangalore Meet


25/61

Thankfully borrowed from ICG Bangalore Meet


26/61

Comparison of SATNAV Systems

WGS-84ITREFPZ-90, ECEFWGS-84, ECEFCoordinate

system

IndiaNot yet knownMin. of DefenceDept. of

Defence, USAirforce

Controlled by

10 years>7 years5 years7.5 yearsSpacecraft life

CDMACDMAFDMA/CDMACDMA

Multiple access

< 8 meters with

GAGAN & < 20

meters with

IRNSS

8 meters10 meters10 metersAbsolute

position

accuracy

L1,L5 / L5 & S-

band

L-bandL-bandL-bandFrequency of

operation

36,000 Km23,616 Km19,100 Km20,200 KmAltitude

2 / 730 , GIOVE-A.14 now, 24 reqd24 (30)

No. of satellites

GAGAN / IRNSSGALILEOGLONASSGPSSystem


27/61

LIMITATIONS OF GPS AND GLONASS

GPS stand alone, cannot satisfy the integrity,accuracy & availability requirements for allphases of flight, particularly for the morestringent precision approaches.

Integrity is not guaranteed, since all satellites

may not be satisfactorily working all times. Time to alarm could be from minutes to hours

and there is no indication of quality of service.

Accuracy is not sufficient even with S/A off, thevertical accuracy for 95%of the time is >10m.

For GPS & GLONASS stand alone systemsavailability & continuity are not assured.

All these calls for a special system addressing allthe above, which could be done by augmenting

the GNSS systems.


28/61

REQUIREMENT OF ENHANCEMENT OF

ACCURACY, AVAILABILITY AND INTEGRITY

For the safety-critical applications it is essentialthat a user be assured that the system is

operating within design tolerances and the

position estimates derived from it can be trusted

to be within specifications This is the socalled integrity requirement.

Timely warning of a system anomaly (which may

be hazardous is called time to alarm.

30Sec En-route

6 Sec APV II (Approach with Vertical Guidance)


29/61

AUGMENTATION OF GPS / GLONASSLIMITATIONS OF GPS:

SIGNAL NOT AVAILABLE INSIDE

TUNNEL & WATER NO ASSURANCE OF AVAILABILITY

AND INTEGRITY OF DATA

CRITICAL FOR AVIATION

APPLICATIONS

ACCURACY REQUIREMENTS

STRINGENT

SPACE BASED AUGMENTATION (SBAS)

WAAS, EGNOS, MSAS & GAGAN

GROUND BASED AUGMENTATION (GBAS) LAAS, PSUEDOLITE, DGPS

AIRCRAFT BASED AUGMENTATION (ABAS)

RAIM (RECEIVER AUTONOMOUS

INTEGRITY MONITORING TECHNIQUE)


30/61

GPS Wide Area Augmentation SystemsGPS Wide Area Augmentation Systems

GAGAN

MSASEGNOS

C-WAAS

WAAS

*

***


31/61

US WIDE AREA AUGMENTATION SYSTEM OF GPS

WAAS

24 Wide Area

Reference Stations

2 Wide Area Master

Stations 2 Navigation Land

Uplink Stations

2 GEOs AOR &POR

FAA presentation to ISRO


32/61

EUROPEAN GEOSTATIONARY NAVIGATION

OVERLAY SERVICE - EGNOS

34 Range IntegrityMonitoring Stations Rims

4 Master Control Stations

2 Navigation Land UplinkStations

2 GEOs INMARSATAOR E & IOR andpresently working onARTEMIS

EGNOSS presentation to ISRO

Japanese S BAS System


33/61

Japanese S-BAS System

(MSAS)

IbarakiIbaraki

MCSMCS

Sapporo GMSSapporo GMS

Fukuoka GMS

Naha GMSNaha GMS

UserUser

Australia MRSAustralia MRS

Hawaii MRSHawaii MRS

Kobe MCSKobe MCS

TokyoTokyo

GMSGMS

GPS ConstellationGPS ConstellationMTSATMTSAT

MCS Master Control StationMCS Master Control Station

MRS Monitor and Ranging StationMRS Monitor and Ranging Station

GMS Ground Monitor StationGMS Ground Monitor Station

KDD 128KbsKDD 128Kbs

NTT 64KbsNTT 64Kbs

MSAS is the Wide area Augmentation System of Japan like WAAS and is based on MTSAT.ICG 2007, Bangalore meet

QZSS Navigation System


34/61

Function distributed in each institute

Timing management, WDGPScorrection, etc.

QZSS

SLR Site

GeonetGSI

Monitor Station NW

User Receiver

TT&CNAV

Message Uplink

Station

WDGPS CorrectionMessage, LEX NAV

L1-SAIF: 1575.42 MHzLEX: 1278.75 MHz

Laser Ranging

Navigation Signals

L1: 1575.42 MHzL2: 1227.60 MHzL5: 1176.45 MHzLEX: 1278.75 MHz

TWSTFTUp: 14.43453GHzDown: 12.30669GHz

Time Management

Station

SLR: Satellite Laser Ranging, TWSTFT: Two Way Satellite Time and Frequency Transfer

Master Control StationMCS)

TT&C, NAVMessage Upload**

**: Under trade-off study between S (Up: 2025-2110, Down: 2200-2290MHz)

and C (Up:5000-5010, Down:5010-5030MHz) band

QZSS Navigation System

Navigation System Architecture


35/61

BEIDOU Chinese regional satellite Navigation System Beidou system consists of two geo-synchronous

satellites in space and a third used as back up, a

control centre located at Beijingand number ofmonitoring and calibration stations on grounddistributed through out China and the Beidoupositioning receivers.

Beidou system is fully operational in early 2004.

Similar to that of the Geostar regional navigationsystem. - Radio determination satellite service(RDSS)

Besides positioning, the system can perform two

way data communication. Users can determine their position and also transmit

messages to each other.

Accuracy (H about 100 meters,

T synch < 10 ms, Taccuracy < 100 ns)

New Chinese

Regional system

announced is

named asCOMPASS and may

consist of GEO, and

some MEO

components


36/61

INDIAN SCENARIO IN GNSS

Satellite Positioning System (SPS) in IRS &

Scientific satellites & GAGAN

Participation in GALILEO & GLONASS

Having our own regional constellation (IRNSS)

Ionospheric & Tropospheric Studies and modeling

India may become biggest user of GNSS for GIS,mobile, survey, mining, fishing industry, aviation,

road, rail transport, etc.


37/61

INSAT IRSLAUNCHVEHICLES

NATIONAL SPACE SYSTEMS

GNSS

GAGANIRNSS

Applications Science


38/61

INDIAN AIRSPACE TO BE SERVICEDINDIAN AIRSPACE TO BE SERVICED


39/61

40 50 60 70 80 90 100 110

-10

-5

0

5

10

15

20

25

30

35

40

INDIAN AIRSPACE TO BE SERVICEDINDIAN AIRSPACE TO BE SERVICED

C BAND


40/61

INRESINRES

INMCC

BANGALORE INLUSBANGALORE

GEO

C BAND

L1 & L5

GAGAN USER

GPS L1 & L2GPS L1 & L2

GPS Nav Data GPS Nav Data

GEO D/L

in L1

GPS & GEO data

Correction

Messages

GPS & GEO data

D/L in C and L

U/L in C

GEO D/L

in L1

GPS and GEO

Broadcast Messages

GAGAN COVERAGE THROUGH INSAT

INDIAN S-BAS PROGRAM GAGAN

GPS AIDED GEO AUGMENTED

NAVIGATION

Indian Master Control Centre


41/61

Indian Master Control Centre The INMCC has been established in

GAGAN AAI premises with all theinfrastructure and facilities atKundalahalli, Bangalore

Factory Acceptance and Site Acceptancetesting of INMCC subsystems havebeen completed

Preliminary System Acceptance Testing

(PSAT) of GAGAN subsystems has beensuccessfully carried out with SatelliteEmulation Subsystem.

GAGAN Master Control Facility

GAGAN Display System Service Monitoring Subsystem

Indian Land Uplinking Station


42/61

Factory Acceptance and SiteAcceptance testing Indian

Land Uplinking Station(INLUS) subsystems havebeen completed

INLUS is co-located withINMCC, Kundalahalli.

A 11 meter C-band dishantenna has been installed. C-band feed is under integration.

KPA and INLUS-RF rack hasbeen integrated and installedat the site.

Indian Land Uplinking Station

GAGAN Uplinking Facility

GAGAN INLUS RF and Signal GenerationSubsystems

Indian Reference Stations


43/61

All the eight Indian Reference Stations(INRES) have been established. FactoryAcceptance and Site Acceptance testingINRES have been completed. All theINRES stations have been linked toINMCC by Optical Fibre Links except forPort Blair.

The indigenously designed Navigationpayload bread-board testing has beencompleted and flight model fabrication is

under progress.

Indigenous development of Navigationsoftware is under development at ISAC.Algorithm for major S/W modules havebeen designed and being coded. Realtime data from INMCC is being archivedin the navigation Software Laboratory

The TEC data received from 18 TECstation is being archived at SAC,Ahmedabad. Iono/Tropo model activityis in progress. Scientists to whom studycontracts have been awarded submittedtheir report.

Indian Reference Stations

Reference Station Antenna

Reference Station Rack

Preliminary System Acceptance Test Results


44/61

Preliminary System Acceptance Test Results

Achieved

position

accuracy inNorth, East

and Up

directions is

better than

the Exit

Criteria

PSAT Exit Criteria

PositionAccuracy better

than 7.5 Meters

GGTAGGTA


45/61

GGTAGGTA


46/61

Locations of GAGAN Reference Stations


47/61

Locations of GAGAN Reference Stations

and

TEC stations

POSITION OF MAGNETIC EQUATOR AND


48/61

POSITION OF MAGNETIC EQUATOR AND

SCINTILLATION REGIONS

INDIAN REGION EXPERIENCES UNPREDICTABLE

IONOSPHERIC DISTURBANCES

SUCCESS OF GAGAN IS DEPENDANT ON THE STUDY AND

MODEL THE IONOSPHERE OVER THE REGION.

GAGAN PERFORMANCE


49/61

GAGAN PERFORMANCE

SPECIFICATIONS Accuracy Integrity Time-to-Alert Continuity Availability

En route

Terminal

Initial & Int

Approach,

NPA,

Departure

APV-I

APV-II

1-10-7 per hr

1-10-7 per hr

1-10-7 per hr

1-2x10-7 per

approach

1-2x10-7 per

approach

5 min

15 sec

10 sec

10 sec

6 sec

0.99 to

0.99999

0.999 to0.99999

0.99 to

0.99999

0.99 to

0.99999

0.99 to

0.99999

1-10-4/hr to

1-10-8/hr

1-10-4

/hr to1-10-8/hr

1-10-4/hr to

1-10-8/hr

1-8x10-6/hr in

any 15 sec

1-8x10-6/hr

in any 15 sec

3.7 km (H)

0.74 km (H)

220 m (H)

220 m (H)

20 m (V)

16 m (H)

8 m (V)

IMPACT AND APPLICATIONS OF GAGAN


50/61

IMAGE CORRECTION/IMAGE CORRECTION/

MAP MAKINGMAP MAKING

NAVIGATION/NAVIGATION/

LANDINGLANDING

ROAD NAVIGATIONROAD NAVIGATION

SHIP ROUTINGSHIP ROUTING

NAVIGATION - AIR, SEA & LANDNAVIGATION - AIR, SEA & LANDPOSITIONING APPLICATIONS -POSITIONING APPLICATIONS -

SURVEYSURVEY

IMAGE CORRECTIONIMAGE CORRECTION

GISGIS

KINEMATIC SURVEYSKINEMATIC SURVEYS

SURVEILLENCE/FLEETSURVEILLENCE/FLEET

MONITORINGMONITORING

INTEGRATED RECIEVER SYSTEMS

PRECISE ORBIT DETERMINATION WAD CORRECTION

ATMOSPHERIC CORRECTION

INTEGRITY MONITORINGTHREAT MODELS & MONITORS SAFETY ISSUES

S-BAS MESSAGES, UPLINK &

SYNCHRONIZATION

TECHNOLOGY ISSUES

APPLICATIONSAPPLICATIONS


51/61

340

550

830

1110

1320

IRNSS

INDIAN REGIONAL NAVIGATIONAL SATELLITE SYSTEM


52/61

IRNSS Architecture


53/61

IRNSS Architecture

Space Segment Seven satellite configuration, 3 SVs in Geo-Stationary orbit ( 34,

83 and 132 East), 4 SVs are in GEO Synchronous orbit placed atinclination of 29 (with Longitude crossing at 55 and 111 East)

The configuration takes care of continuity of service with a failureof one satellite.

The satellites are of 1 ton class with navigation payload of 102Kgs and power consumption of 676 Watts .

There will be two downlinks (L and S bands) providing dualfrequency operation with EIRP of 31.5 dBW at EOC. The payload will have 3 Rubidium clocks.

Ground Segment Master Control Center

IRNSS Ranging & Integrity Monitoring stations (IRIM) IRNSS Telemetry and Command stations Navigation Control Centre IRNSS Network Timing Centre

User Segment

Planned operationalization by 2011-2012


54/61

HDOP & VDOP (99%) for theProposed Constellation

GEO 34,83,132

GSO 55(55,235), 111(111,291)

User Mask Angle 5deg

IRNSS Coverage Area

IRNSS Error Budget


55/61

IRNSS Error Budget

6.5~9.9

Pos. Accu.-V(m)

4.3~9.9Pos. Accu.-H(m)

2.33.0VDOP

1.53.0HDOP

2.843.3UERE(m)

1.51.0Multipath0.60.6Rx. Noise

0.20.2Troposphere

0.51.2Ionosphere

1.82.0Clock

1.42.0EPH

(1 sigma)(1 sigma)Error

GPS(D)IRNSS(D)SYSTEM

IRNSS system provides the Dual frequency user with

a targeted position accuracy better than 10 metres

in the coverage area.


56/61

NAVIGATION

SPACECRAFT

AIRCRAFT

SHIP

VEHICLE

GEOGRAPHIC DATA

COLLECTION

MAPPING

SURVEYING

ENGINEERING

SCIENTIFIC RESEARCH

ATMOSPHERIC STUDIES GEODYNAMICS

CRUSTAL MOVEMENTS

CRUSTAL DEFORMATIONS

MILITARY

NATURAL RESOURCE AND LAND

MANAGEMENT

GIS INGEST FOREST MENSURATION

TOWN PLANNING

FLEET MOVEMENT

ROUTING/ALIGNMENT

MONITORING THE HEALTH OF TALL

BUILDINGS/TOWERS, LONG BRIDGES

Power grid synchronization

AGRICULTURE

PRECISION FARMING

EMERGENCY RESPONSE

SEARCH AND RESCUE

BUSINESS SOLUTIONS

LOCATION BASED SERVICES

MOBILE

TOURISM

RETAILING/Banking

Assisted GNSS Applications


57/61

Satellite positioning

systems (GPS, Galileo,

GLONASS)

Satellite positioning

augmentation systems

(EGNOS, WAAS)

Mobile

communications

signaling network(s)

Location server(s)Fixed

telecommunications

network nodes with

short-range wireless

data communications

equipment (Bluetooth,

WLAN)

Terrestrial positioningsystems (LORAN C)

Inertial navigation

sensors (implemented

into the rover itself:

accelerometer,

barometer)

ASSISTED-GNSS

POSITIONING

ALGORITHM

pp

AREAS OF RESEARCH & DEVELOPMENT IN


58/61

POSITIONING AND TIMING SYSTEM

(GNSS)

SCIENCE

IONO-TROPO MODELLING IN THE

EQUATORIAL REGION IN L-BAND

RADIO OCCULTATION STUDIES

FOR NEAR EARTH

ATMOSPHERIC TEMPERATURE

PROFILE

REAL-TIME WEATHERFORECASTING

TECHNOLOGY

PRECISION ORBITS

TIME SYNCHRONISATION

DEVELOPMENT OF NAVIGATION

SOFTWARE

ATOMIC CLOCK RUBIDIUM, CESIUM,

HYDROGEN MASERS

ISOFLUX ANTENNAS FOR SPACECRAFT

DUAL RECEIVERS (GPS+GLONAAS,

GPS+GALILEO)

ACCURATE ESTIMATE OF PHASE DELAYS

ONBOARD SATELLITE

I l t d ith GNSS


59/61

Issues related with GNSS

Interoperability refers to the ability of open globaland regional satellite navigation and timing servicesto be used together to provide better capabilities atthe user level than would be achieved by relying

solely on one service or signal.

Compatibility refers to the ability of space-basedpositioning, navigation, and timing services to be

used separately or together without interfering witheach individual service or signal.

I l t d ith GNSS


60/61

Issues related with GNSS

Intentional and Unintentional Interferences

Multipath, Indoor and Urban Environment Over crowding of Frequency Spectra

Need for higher anti-jamming margins

Protection of RNSS and Radio Astronomy bands

Continuity of existing and planned constellations Ionospheric and Solar weather impact on GNSS signals

Standardization of Civilian Signals and Receivers

Universal Time and Reference Frames (Each

Constellation as of today has adopted different time andgeodetic reference frames)


61/61

CONCLUSION

After all, we need measurements of space and time foralmost all our activities and GNSS provides these.

Hence, GNSS will influence our life more than any othertechnological advent.

Documents

IEEE AESS Houston Modified