Presentation on theme: "Indian Satellite Navigation Programme N. G. Vasantha Kumar Dy. Director (Satnav & ACS) Indian Space Research Organisation INDIA."— Presentation transcript:
Indian Satellite Navigation Programme N. G. Vasantha Kumar Dy. Director (Satnav & ACS) Indian Space Research Organisation INDIA
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 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 Augmentation systems in the World 2010(?) 2008 2011 2012 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) GAGAN GPS 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 SEGMENT Three GEO Satellites Two operational Navigation PayloadsTwo operational Navigation Payloads One in-orbit spare Navigation PayloadOne in-orbit spare Navigation Payload GROUND 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 INRESs INMCC 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 SignalsFrequency Band 1 MHz BPSKL1 (1575.42 MHz) 10 MHz BPSK *L5 (1176.45 MHz) * When GPS L5C is available
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. IRNSS Indian Regional Navigation Satellite System
IRNSS Indian Regional Navigation Satellite System OBJECTIVES Reliable Position, Navigation and Timing services over India and its neighbourhood To 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.
3 GSO satellites at 34 0, 83 0, and 131.5 0 East. 4 Inclined GSO satellites at 29 0 inclination with Longitude crossing at 55 0 and 111.5 0. 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 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
AccuracyIntegrityTime-to-AlertContinuityAvailability En route Terminal Initial & Int Approach, NPA, Departure APV-I APV-II CAT I 1-10 -7 per hr 1-2x10 -7 per approach 5 min 15 sec 10 sec 6 sec 0.99 to 0.99999 0.999 to 0.99999 0.99 to 0.99999 1-10 -4 /hr to 1-10 -8 /hr 1-10 -4 /hr to 1-10 -8 /hr 1-10 -4 /hr to 1-10 -8 /hr 1-8x10 -6 /hr in any 15 sec 3.7 km (H) 0.74 km (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
GAGAN PAYLOAD CHARACTERISTICS RHCP Transmit polarisation6. 50 KgTotal Payload weight10. 40W RF Power rating9. 15.8 dB Antenna Gain8. Helix Type of Antenna7. C-band Feeder Link frequency5. Global Footprint4. 240WPower D C11. 24 MHz 20 MHzBandwidth3. -2 dB/deg.K Receive 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 Nos IRNSS Network Time ( IRNWT ) - 2 Nos IRNSS CDMA Ranging Stations ( IRCDR ) - 4 Nos IRNSS Laser Ranging Service ( ILRS ) IRNSS Range and Integrity Monitoring Stations -16 Nos IRNSS Data Communication Network (IRDCN) - 2 Nos IRNSS Satellite Control Facility ( IRSCF ) IRNSS TTC & Land Uplink Stations (INLUS) - 9 Nos IRNSS 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
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.