STATEOFTHEART ARCHITECTURE OF SBAND TTC NETWORK IN INDIA

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STATE-OF-THE-ART ARCHITECTURE OF S-BAND TTC
NETWORK IN INDIA T2-060 J. RAMASUBRAMANIANV.JA
LARAMAIAHS.K.SHIVAKUMARISTRAC/ISRO, Bangalore,
INDIA Space Ops 2002
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INTRODUCTION

• ISRO TELEMETRY, TRACKING COMMAND NETWORK
  (ISTRAC)
• PROVIDES TTC SUPPORT FOR LOW EARTH ORBITING
  SPACECRAFT MISSIONS.
• CURRENTLY UNDERGOING THE PROCESS OF
  MODERNISATION.
• AFTER COMPLETION, IT IS EXPECTED TO FULFIL
  THE
• REQUIREMENTS OF INDIAN SATELLITES
  PROGRAMME, HAVE TOTAL COMPATIBILITY WITH CCSDS
  STANDARDS AND WILL BE ABLE TO PROVIDE CROSS
  SUPPORT FOR ANY EXTERNAL AGENCY.

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M C
LCK G/S     LCK-1 LCK-2
MAU G/S      
BIAK G/S      
64 KBPS
64 KBPS
64 KBPS
SCC LAN (ETHERNET)
BLR G/S     BLR W BLR E
BRK G/S   BRK 1 BRK 2  
64 KBPS
SPACECRAFT CONTROL CENTRE(SCC)
MC
Occasional Support Not in Regular Network
64 KBPS
NCC at BLR
MC
SHAR G/S
M C
SHAR-1
SHAR-2
MC
MC
FIG2.1 ISTRAC TTC NETWORK FOR SATELLITE MISSION
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GOALS, PLAN APPROACH

• GOALS
• AUTOMATION OF GROUND STATION OPERATIONS.
• REMOTE CONFIGURATION AND MONITORING OF ALL GROUND
  STATIONS FROM A NETWORK CONTROL CENTER (NCC)
  LOCATED AT SCC
• INSTALLATION OF COMPACT, STATE-OF THE-ART
  EQUIPMENT/SUBSYSTEM.
• IMPROVED STATION PERFORMANCE.
• EQUIPPING GROUND STATIONS WITH SYSTEMS
  COMPATIBLE TO CCSDS STANDARDS TO PROVIDE CROSS
  SUPPORT.

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• APPROACH
• THE FIRST GROUND STATION THAT WILL BE MODERNIZED
  WILL SERVE AS A MODEL GROUND STATION AND WILL
  PROVIDE NECESSARY EXPERIENCE TO UNDERSTAND AND
  SOLVE ALL TYPES OF INTERFACE PROBLEMS.
• A NEW CONFIGURATION WITH ALL NEW SYSTEMS IS BEING
  PLANNED AND IMPLEMENTED NO INTERFACING PROBLEMS
  WITH OLD SUBSYSTEMS NEED TO BE ADDRESSED.
• RESULTS IN MINIMUM DOWN TIME WHILE CHANGING OVER
  FROM OLD TO NEW CONFIGURATION, AS THE EXISTING
  SYSTEM WILL NOT BE DISTURBED AND WILL CONTINUE TO
  PROVIDE SUPPORT TILL THE NEW CONFIGURATION IS
  READY.

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• PLANS
• INDIGENOUS RESEARCH DEVELOPMENT EFFORTS IN
• THE FOLLOWING AREAS
• ANTENNA MOUNT REFLECTOR
• ANTENNA FEED
• DRIVE SYSTEM
• STATION COMPUTER SYSTEM
• REMOTE MONITORING AND CONTROL SYSTEM

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MISSION REQUIREMENTS

• INDIAN MISSIONS
• TTC SUPPORT FOR MAXIMUM NUMBER OF ORBITS WITH
  RESPECT
• TO A GROUND STATION.
• CONTINUOUS TC SUPPORT FROM 5 EL TO 5 EL.
• TRACKING DATA ACQUISITION SUPPORT FOR THE
  REQUIRED
• PERIOD WITHIN THE PASS.
• CARRYOUT SATELLITE CONTROL OPERATIONS THROUGHOUT
  
• MISSION LIFE.
• CARRYOUT TM AND TRK DATA PROCESSING,
• ORBIT DETERMINATION AND GENERATE STATE VECTOR
  w.r.t G/S
• FOR SCHEDULING TRACKING FURTHER ORBITS.
• PROVIDE COMMUNICATION SUPPORT FOR DATA TRANSFER
  
• THROUGHOUT MISSION LIFE.

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EXTERNAL MISSIONS

• TTC SUPPORT FOR LEOP/GTO SUPPORT.
• PROVISION FOR DERANDOMISING, RS DECODING/VITERBI
  DECODING BEFORE DEMULTIPLEXING AS PER CCSDS
  STANDARDS.
• TC UPLINK IN CCSDS FORMAT, PSK SUB CARRIER
  MODULATED, PM CARRIER MODULATED.
• TRACKING DATA COLLECTION AND FORMATTING AS PER
  REQUIREMENT.

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Acq Ant
?Az El
Az El
1 6

SW
TRK Rx 3Ch
DC1
To WEST ACU
BLR WEST 10 m
Az El
Az El
IF MATRIX 4X4 SW IFM1
TRK Rx-1
Test/Sim I/P
BLR EAST
Az El
TRK Rx-2
TLT
Err Selection Sw
???
1 3
Az El
To EAST ACU
TC 3 No s
MC
LNA 3 No s
DC2
Az El
TRK Rx-3
MC
Test/Sim I/P
STC1 STC2 STC3 STC4
TC
TTC Proc - 1
From TRK Rx
ACU
Servo PWM Drive
IF MATRIX SW IFM2
DC3
?R ?L
TTC Proc - 2
TC
HPA SSPA IFMs
3 x 5 Video SW
3 x 5 Video SW
U/C s
MCP - 1
U/L
TTC Proc - 3
TC
BLR EAST
LNA D/Cs TTC STC
NCC
TTC Proc -4
MCP - 2
G/S LAN
LAN
BLR EAST 10 m
IF MATRIX SW IFM
HPA-1
UDC 1
TC
Verif.ch
Dummy Load
HPA-2
Verif.ch.
UDC 2
TLT
BLR EAST
HPA-3
UDC 3
External Agency LAN
External Agency TC, TM Equpt
From ACU
Servo PWM Drive
Dummy Load
SSPA
UDC 4
U/L
PSK MOD
SIG GEN
SIMULATION
GPS Rx-1
FDU
PCM SIM
SW
To TEST / SIM I/P
GPS Rx-2
TDU
From TTC proc sim
UC (TTC PRO )
FREQUENCY TIMING SYSTEM
LO
TLT
TLT antenna
Fig 4.2 TYPICAL GROUND STATION CONFIGURATION
FOR IRS SUPPORT
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TABLE 5.1.1 GROUND STAIONS CAPABILITIES

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TABLE 5.1.2 SPECIFICATIONS FOR A TYPICAL TTC
GROUND STATION.  
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(No Transcript)
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SALIENT FEATURES OF SUBSYTEMS
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ANTENNA DRIVE SUBSYSTEM

• EACH G/S WILL HAVE
• A 10m DISH WITH A G/T OF NOT LESS THAN 21 dB/K
  FOR RCP
• AND LCP EIRP OF 72 dBW.
• AN ACQUISTION OF 7 deg BW AND G/T OF -5dB MOUNTED
  IN THE
• AXIS OF MAIN DISH OVER SUBREFLECTOR.
• ANTENNA SERVO CONTROL SYSTEM WITH PWM AMPLIFIERS
• AND BRUSHLESS DC MOTORS.
• RECEIVE SUBSYSTEM
• EACH RECEIVE CHAIN WILL HAVE POLARISATION
  DIVERSITY
• RECEPTION.
• STATE OF THE ART TTC-PROCESSORS FOR
• DEMODULATION, DECOMMUTATION AND DATA OUTPUT.
• PROVISION FOR CCSDS STANDARDS FOR TM,TR,TC DATA.
• ALL DATA O/P ON LAN.

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TRANSMIT SUBSYSTEM

• HPAs AND TWTAs CONFIGURED IN COLD REDUNDANCY.
• REMOTELY CONFIGURABLE TUNABLE WITHIN 10
• SECONDS.
• STATION COMPUTER SUBSYSTEM
• ACQUIRES TM TR DATA FROM G/S LAN.
• FORMATS DATA AS PER USER REQUIREMENTS AND
• TRANSMITS TO SCC COMPUTERS FACILITY FOR DATA
• USERS.
• HOUSES COMMAND GENERATOR HARDWARE AND
• INTERACTS WITH COMMAND EXECUTION PROCESS FOR
• TRANSMISSION OF TC.

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SIGNAL DATA SIMULATOR

• INDEPENDENT PCM DATA STREAM SIMULATION FROM A
• STAND ALONE PCM SIMULATOR (SOFTWARE), WHOSE
• OUTPUT WILL BE FIRST MODULATED ON A SUB
  CARRIER
• AND THEN ON THE RF CARRIER OR PCM DATA
  MODULATION
• ON THE RF CARRIER DIRECTLY.
• SIMULATED DATA OUTPUT FROM BASE BAND SYSTEM FOR
  
• EACH TYPE OF DATA (eg. TTC PROCESSOR) TO BE
• UP- CONVERTED TO S-BAND Rx FREQUENCY AND TO
  BE FED
• TO SIMULATION INPUT OF Rx CHAIN FOR TEST AND
  BER
• MEASUREMENTS.
• A TEST LOOP TRANSLATOR INPUT TO THE Rx CHAIN FOR
• RANGING AND DOPPLER CALIBRATION.

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MONITORING CONTROL SYSTEM

• EACH G/S WILL HAVE TWO MCPs (MONITOR AND CONTROL
• PROCESSOR).
• MCPs WILL BE CONNECTED TO A CENTRAL NETWORK
• CONTROL PROCESSOR(NCP) LOCATED AT NETWORK
• CONTROL CENTRE(NCC) VIA DEDICATED WAN.
• MCPs WILL HAVE CONNECTIVITY TO GENERAL EQUIPMENT
• INTERFACE(GEIs) WHICH WILL INTURN HAVE
  CONNECTIVITY
• TO ALL G/S EQUIPMENT.
• IN THE ABOVE CONFIGURATION, ALL G/S EQUIPMENT
  WILL
• BE REMOTELY CONFIGURED AND CONTINUOUSLY
• MONITORED.

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FREQUENCY TIMING SUBSYSTEM

• EACH G/S WILL HAVE TWO GPS Rx WITH BUILT-IN
• DISCIPLINED OSCILLATORS FOR PROVIDING
  UNDISTURBED
• FREQUENCY AND TIMING SIGNALS.
• STABILITY WILL BE IN 1011 PARTS/DAY.
• A SWITCHING UNIT WILL ACCEPT FREQUENCY TIMING
• SIGNALS FROM BOTH GPS Rx AND SWITCH THEM
• AUTOMATICALLY TO THE CONFIGURED EQUIPMENT.
• MCS OF THE G/S WILL HAVE THE MONITORING CONTROL
• FUNCTIONS OF BOTH GPS Rxs, SWITCHING AND
  DISTRIBUTION
• UNITS.

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