Indian Satellite Navigation Programme N. G. Vasantha Kumar Dy. Director (Satnav & ACS) Indian Space Research Organisation INDIA.

Indian Satellite Navigation Programme

N. G. Vasantha KumarDy. Director (Satnav & ACS)

Indian Space Research OrganisationINDIA

Basic Positioning: Today

• Navigation satellites are Earth Satellites.• Follow Kepler’s laws of motion, transmit their Position,

Navigation, Time (PNT).• Provide PNT service through hand-held receivers to users.• Satellites’ orbits and health monitored through an

elaborate ground segment.

10-20 m10-20 m

All Global Systems have more than 24 satellites each in 19000 – 24000 km altitude orbits. All transmissions from the satellite to date are in L-band.

The satellites transmit the ephemeris, clock and ionospheric data. The details of the signal structure and data structure vary slightly.

User receivers measure their distance from at least 4 satellites through one-way ranging technique. Most downlink signals use Code Division Multiple Access (CDMA) and RF modulation such as, BPSK, Binary Offset Carrier (BOC) etc. GLONASS uses CDMA ranging codes with Frequency Division Multiple Access (FDMA)

These constellations represent a wonderful laboratory for fundamental scientific work

GPS GLONASS GALILEO

Global Satellite Navigation Systems

Spectrum for GNSS

GNSS spectral bands are:

• L1 (1559 – 1610 MHz),• L2 (1215 – 1300 MHz),• L5 (1164 – 1215 MHz), • S-band (2483.5 – 2500 MHz)

L1 and L2 bands are being used for 30 years now. L5 is the latest and much sought after band. S-band is for Regional use in Region 3. The World Radio

Conference (WRC-12) will discuss global allocation for this band.

GPS GPSGPSGALILEO GLONASS GLONASS

1164

.000

M

Hz

1188

.000

MH

z

1212

.000

M

Hz

1215

.000

MH

z

1215

.600

MH

z

1260

.000

MH

z

1237

.827

MH

z12

39.6

00 M

Hz

1261

.610

MH

z

GALILEO

1300

.000

MH

z15

59.0

00 M

Hz

1592

.952

MH

z

1610

.000

MH

z16

20.6

10 M

Hz

1626

.500

MH

z

1587

.420

MH

z

1563

.420

MH

z

GALILEO

5010

.000

MH

z

5030

.000

MH

z

Radioastronomy1610.6 – 1613.6 MHz

L5 L2 S

E5

2483

.5 -

250

0 M

Hz

L1 C

Spectral bands for Radio Navigation Satellite Systems

GPS Augmentation systems in the World

EGNOSWAAS MSAS

2010(?)2008 20112012

GAGAN

GAGAN is a Satellite Based Augmentation System being implemented by India based on GPS

GAGAN jointly implemented by ISRO and Airports Authority of India (AAI)

GAGAN implementation in two phases GAGAN – TDS (Technology Demonstration System) GAGAN – FOP (Final Operation Phase)

GAGANGPS Aided GEO Augmented Navigation

OBJECTIVE

To provide Satellite-based Navigation services with accuracy and integrity required for civil aviation applications over Indian Air Space.

Better Air Traffic Management over Indian Airspace.

GAGAN

SPACE SEGMENTSPACE SEGMENTThree GEO SatellitesThree GEO Satellites• Two operational Navigation Payloads Two operational Navigation Payloads • One in-orbit spare Navigation PayloadOne in-orbit spare Navigation Payload

GROUND SEGMENTGROUND SEGMENT• Indian Master Control Centre (INMCC) Indian Master Control Centre (INMCC) • Indian Navigation Land Uplink Station (INLUS)Indian Navigation Land Uplink Station (INLUS)• Indian Reference Stations (INRES)Indian Reference Stations (INRES)• Communication linksCommunication links

GAGAN CONFIGURATION

INRESsINMCC

GPS GPS

INRESs

GEO

INLUS

User

(Navigation Payload)

GAGAN NAVIGATION SIGNALS

10

GAGAN Space Segment uses SBAS PRN codes 127 and 128 to transmit corrections and integrity parameters to SBAS receiver.

Signals Received by GAGAN Receiver

Signals Frequency Band

1 MHz BPSK L1 (1575.42 MHz)

10 MHz BPSK * L5 (1176.45 MHz)

* When GPS L5C is available

GAGAN CONFIGURATION

High position accuracies with integrity (APV-1.5 or better) over a wide geographical area such as the Indian Airspace.

These position accuracies to be simultaneously made available to all airports and air fields in Indian FIR, enabling satellite based landing of aircraft fitted with SBAS receivers.

To provide fuel efficient air corridors.

Better upper Air-space management over India.

GAGAN INTENDED SERVICES

IRNSS is an independent regional navigation system

7 satellite constellation and ground segment.

Coverage area is about 1500 km beyond Indian territory.

Estimated horizontal position accuracy of 10m in over India and adjoining areas.

IRNSSIndian Regional Navigation Satellite System

IRNSSIndian Regional Navigation Satellite System

OBJECTIVES

Reliable Position, Navigation and Timing services over India and its neighbourhoodTo provide fairly good accuracy to the user.Most of the constellation is seen by user all the time. Integrity and ionospheric correction messages to user.

IRNSS CONFIGURATION

IRNSS SPACE SEGMENTIRNSS SPACE SEGMENT

3 GSO satellites at 340, 830, and 131.50 East.

4 Inclined GSO satellites at 290 inclination with Longitude crossing at 550 and 111.50.

To be launched by Indian PSLV.

First satellite launch by second half of 2011.

Full constellation completion by 2014.

Space segment will be augmented with 4 more satellites to make 11 satellite constellation with better coverage and accuracy.

IRNSS SPACE SEGMENTIRNSS SPACE SEGMENT

IRNSS Navigation Control Facility ( IRNCF )IRNSS Navigation Centre ( INC ) IRNSS Network Time ( IRNWT ) IRNSS CDMA Ranging Stations ( IRCDR ) IRNSS Laser Ranging Service ( ILRS )IRNSS Range and Integrity Monitoring Stations IRNSS Data Communication Network (IRDCN)

IRNSS Satellite Control Facility ( IRSCF )IRNSS TTC & Land Uplink Stations (INLUS) IRNSS Satellite Control Centre ( IRSCC )

IRNSS- GROUND SEGMENT Architecture

20

IRNWT

IRNSS- GROUND SEGMENT Architecture

IRIMS1

IRIMS16…..

IRNSS Laser Ranging

(IRLSF)

IRNSS Navigation CentreBangalore

IRNSS CDMA Ranging

4 (IRCDR)

IRCDRIRNSS

CDMA Ranging 1

(IRCDR)

IRCDR

Backup INC

IRMNC Computer

IRDCN IRIMS

IRNSS NAVIGATION SIGNALS

SPS RS

L5 (1176.45 MHz ) BPSK BOC (5,2)

S band (2492.028 MHz)

BPSK BOC(5,2)

CDMA Ranging Frequencies

•Uplink : 6712 .0MHz (B.W 24MHz)•Downlink : 3412 .0 MHz (B.W 24MHz)

21

IRNSS NAVIGATION SIGNALS

THANK YOUTHANK YOU

GNSS- Aviation Alert Limits

Accuracy Integrity Time-to-Alert Continuity Availability

En route

Terminal

Initial & Int Approach, NPA, Departure

APV-I

APV-II

CAT I

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

1-2x10-7 per approach

5 min

15 sec

10 sec

10 sec

6 sec

6 sec

0.99 to 0.99999

0.999 to 0.99999

0.99 to 0.99999

0.99 to 0.99999

0.99 to 0.99999

0.99 to 0.99999

1-10-4/hr to1-10-8/hr

1-10-4/hr to1-10-8/hr

1-10-4/hr to1-10-8/hr

1-8x10-6/hr in any 15 sec

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)

16 m (H)6-4 m (V)

GNSS- Aviation Operational Performance Requirements

IRNSS Data Structure

SUBFRAME

1

SUBFRAME

2

SUBFRAME

3

SUBFRAME

4

300 BITS 300 BITS 300 BITS 300 BITS

1 23 45 277

TLM HOW DATA CRC

22

BITS

22

BITS

232 BITS 24 BITS

Master Frame

Sub Frame

GAGAN PAYLOAD CHARACTERISTICS

RHCPRHCPTransmit polarisation6.

50 Kg Total Payload weight10.

40W40WRF Power rating9.

15.8 dB15.8 dBAntenna Gain8.

Helix HelixType of Antenna7.

C-bandC-bandFeeder Link frequency 5.

GlobalGlobalFootprint4.

240WPower D C11.

24 MHz20 MHzBandwidth3.

-2 dB/deg.K-2 dB/deg.KReceive G/T2.

29.2 dBW 30.2 dBWTransmit EIRP (EOC)1.

L5 Freq. (1176.45 MHz)

L1 Freq.

(1575.42 MHz)

System characteristics

Sl. No.

IRNSS Navigation Control Facility ( IRNCF )IRNSS Navigation Centre ( INC ) - 2 NosIRNSS Network Time ( IRNWT ) - 2 Nos IRNSS CDMA Ranging Stations ( IRCDR ) - 4 NosIRNSS Laser Ranging Service ( ILRS )IRNSS Range and Integrity Monitoring Stations -16 NosIRNSS Data Communication Network (IRDCN) - 2 Nos

IRNSS Satellite Control Facility ( IRSCF )IRNSS TTC & Land Uplink Stations (INLUS) - 9 NosIRNSS Satellite Control Centre ( IRSCC ) - 2 Nos

IRNSS- GROUND SEGMENT Architecture

Challenges in Technology

• Astronomy ( Orbital Mechanics )- Precision Orbits, Accurate Ephemeris determination

• Signal structure – Modulation and Codes• Stable On-board atomic clocks and their estimation • Atmospheric Science – Modeling delays• GNSS Receiver technology, indoor positioning • The ICE (Ionosphere, Clock, Ephemeris) errors• Hazardously Misleading Information (HMI) • GAGAN certification, Software standards• ‘Safety of Life’ system Software and its certification

Applications of Satellite Navigation systems

Break down of turnover

Personal Mobility

Mass Market Vehicles

Commercial Vehicles

Aviation

Maritime

Emergency Services

Survey

Others

Satellite Communications and Navigation programme of ISRO/DOS

• Leadership in Satellite Communication demonstrated through the deployment of the INSAT system since 1982.

• Leadership in Satellite Navigation through deployment of GAGAN and IRNSS to be demonstrated in this decade. GAGAN is an AAI-ISRO Project.

• Continue to maintain leadership in these areas to serve India and its people.

• Develop technical and human resources to address technology issues. Coordinate and use spectrum.

• Satellite based communication and navigation systems for rural connectivity, security needs and mobile services.