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ISRO-NRSC-SDR&ISA-GISAT-RFP

DATA RECEPTION SYSTEM FOR

GEO IMAGING SATELLITE AT NRSC, SHADNAGAR, TELANGANA,

INDIA

May, 2016 Satellite Data Reception & Ingest Systems Area

National Remote Sensing Centre Indian Space Research Organization

Balanagar, Hyderabad

RReeqquueesstt FFoorr PPrrooppoossaall ((RRFFPP)) ooff

SSuuppppllyy,, IInnssttaallllaattiioonn aanndd CCoommmmiissssiioonniinngg

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CONTENTS

1. INTRODUCTION...........................................................................................4

2. SCOPE OF THE WORK…………………………………….………….........4

3.OVERALL TECHNICALSPECIFICATIONS.................................................5

4. SYSTEM DESCRIPTION................................................................................8

5. RF SYSTEMS...................................................................................................8

5.1 ANTENNA AND FEED SYSTEM................................................................9

5.2 DOWN CONVERTERS.................................................................................9

5.3 FIBER OPTIC LINK INTERFACE.............................................................10

5.4 QPSK DATA DEMODULATOR................................................................10

6. ANTENNA CONTROL SERVO SYSTEM.................................................16

6.1 SYSTEM DESCRIPTION...........................................................................16

6.2 SYSTEM OPERATING MODES...............................................................16

6.3 SYSTEM SAFETY INTERLOCKS............................................................18

6.4 SYSTEM STATUS DISPLAY....................................................................20

6.5 SYSTEM FUNCTIONAL REQUIREMENTS...........................................20

6.6 SYSTEM SPECIFICATIONS.....................................................................22

6.7 ANTENNA CONTROL UNIT....................................................................22

6.8 FEATURES AND FUNCTIONS OF ACU.................................................24

6.9 REMOTE ANTENNA CONSOLE ( RAC).................................................25

6.10 SYSTEM CONTROL SOFTWARE AND SOFTWARE TOOLS............25

6.11 ACU M& C WINDOWS APPLICATION SOFTWARE..........................25

6.12 RAC M & C WINDOWS APPLICATION SOFTWARE.........................26

6.13 INSTRUMENTATION SOFTWARE/DIAGNOSTIC TOOLS................26

6.14 ANTENNA MOTOR AND DRIVE SYSTEM..........................................27

6.15 DRIVE AMPLIFIER SPECIFICATIONS.................................................28

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6.16 ANTENNA DRIVE UNIT.........................................................................29

6.17 ADU SPECIFICATIONS...........................................................................29

6.18 MECHANICAL ASPECTS........................................................................30

6.19 ENCODER BOX........................................................................................30

7. MECHANICAL SYSTEMS.........................................................................31

7.1 DESCRIPTION OF THE PROPOSED ANTENNA MECHANICAL

SYSTEM........................................................................................................31

7.2 MECHANICAL CONSIDERATIONS FOR ANTENNA DESIGN...........32

7.3 STRUCTURAL ANALYSIS AND DESIGN DETAILS............................32

7.4 CIVIL WORKS FOR ANTENNA PEDESTAL..........................................33

8. LIST OF KU-BAND DATA RECEPTION SYSTEM…………………...…33

9. RELIABILITY AND QA REQUIREMENTS..............................................34

10. SYSTEM INSTALLATION AND INTEGRATION..................................34

11. PROGRAMME CLAUSES.........................................................................35

12. ACCEPTANCE TEST PLAN / TESTING METHODOLOGY................35.

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1 Introduction National Remote Sensing Centre (NRSC) is one of the Centers of Indian Space Research Organisation (ISRO) under the Department of Space, Government of India. The prime responsibility of NRSC is acquisition of Earth Observation Data from Remote Sensing Satellites, product generation & Dissemination as well as application development, Aerial services and capacity building. In the coming years ISRO is planning to launch Geo Imaging satellites for Disaster management. The satellites transmit data to ground in Ku-band (10.70 GHz to 12.75 GHz) with signals in vertical and horizontal polarization. NRSC has the responsibility for setting up of Ku-band ground stations. Accordingly, National Remote Sensing Centre (NRSC) is planning to establish Two Ku-Band ground stations at NRSC Shadnagar, Telangana State, India. The new Ku-Band Reception system shall have the capability to track and receive data in Ku-Band. This document provides technical specifications and requirements of Ku-band Reception system. The details and requirements identified in this document may undergo some changes due to the on-going refinements based on discussions with application scientists in order to make it most suitable for intended applications.

2 Scope of the work The work includes supply, installation and commissioning of Two Ku-Band Data Reception Systems at NRSC, Shadnagar, Mahbubnagar District, Telangana State. The Data Reception System (DRS) shall have the capability to track the GEO satellites of 36500Kms orbit onwards. The systems shall be installed and interfaced with the ground station control-room systems. The operations of Reception System shall be performed from the pedestal room. The IF data transfer from pedestal room to Control Room will be done using high speed fiber optic links. The distance may be more than 1 Km from antenna pedestal room to Control Room . NRSC intends to entrust the task of Supply and installation of ‘Ku-Band Data Reception System’ to an industry on turn-key basis. The implementation of the project includes system engineering, design/development, supply of the system (hardware & software) and installation & commissioning of Ku-Band Data Reception System, on NRSC supplied foundation. The DRS system should meet all the Data Reception Requirements of GISAT 1 & 2, and should also be upgradable to meet the DRS requirements of Future GISAT missions. The system being offered should be proven and should have already been operational for at-least one year by the time of supply. The Supply and installation of ‘Ku-Band Data Reception System’ will involve (not limited to) the following minimum activities as under:

Understanding the requirements Installation, Commissioning and on-site acceptance testing. Supply of various Hardware/Software systems. Civil works for Antenna base structure will be the responsibility of NRSC.

Necessary drawings and inputs for civil structure shall be provided by vendor. Equipment Transportation to site

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Documentation, User manual and Training Capability to support the systems for at least ten years of post-Installation. Warranty and post warranty services Supply of required interfacing cables of all types, wave guides, patch panel, patch

cords, coaxial connector, Light interface units, Fiber optic cables, Fiber optic link spares etc.

The project management team of NRSC will periodically review the technical, commercial and managerial aspects of the activity. The typical reviews will be as under:

Preliminary Design Review with test plans Critical Design Review Factory Acceptance Tests Final On-site Acceptance Tests

The Vendor has to provide specifications for Pedestal civil works to withstand vibrations, wind gusts, earth quakes etc. The civil construction works will be initiated by NRSC immediately after the placement of the purchase order for antenna pedestal construction. The vendor has to provide the appropriate drawings/ details wherever NRSC System interface is involved. The technical information and other details shared by NRSC shall remain exclusive property of NRSC. Vendor shall make no attempt to unlawfully reveal or misuse the data/information provided by NRSC.

3 Overall Technical Specifications

Table-1:KU-BAND RECEPTION SYSTEM SPECIFICATIONS

SL NO PARAMETERS SPECIFICATIONS

1 Feed Configuration Cassegranian, Monopulse, Receive only, Two port

2 Main Reflector

Minimum of 9 M diameter Shaped Parabolic, Aluminum alloy

3 Main reflector and Sub-reflector surface accuracies

0.3 mm RMS and 0.15 mm RMS or better than mentioned.

4 Frequency Range 10.7 to 12.75 GHz

5 Feed Polarization Linear, Simultaneous Vertical and Horizontal, orient-able

6 G/T Better than 38 dB/deg K @20 deg EL 7 Feed VSWR 1.3:1 (Maximum)

8 Radiation patterns & side lobe level As per ITU-R Rec.580-5

9 First Side lobe level Minimum 14dB below main lobe 10 Cross polarization Isolation 35dB minimum within 1dB beam width. 11 Tracking Receiver Frequency Band: 720 to 1200 MHz

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Sensitivity : better than -100 dBm 11 LNA noise temperature Better than 65 dB/Deg K

12 LNA System Tri-redundant configuration

13 L-band Input IF frequency 1200MHz +/- 200 MHz

14

Spurious @ receive IF port at nominal output power

Less than – 65dBc

15 Modulation Scheme BPSK/QPSK/UQPSK/8PSK with convolution coding, FEC 7/8 and RS (255,239) decoder

16 BER Performance 1.0 x 10 -8 at 7dB Eb/N0

17 Fiber-optic Transmitter/Receiver Frequency range 50 MHz to 3.5 GHz

18 Antenna Mount EL Over AZ 19 Servo Drive Geared Servo motor with feedback

20 Operational Modes Auto Track/Step Track/ Program track /Adaptive Track/ Manual

21 Azimuth travel range 0 to 180 deg Continuous 22 Elevation Travel range 0 to 90 deg continuous

23 Velocity (AZ and EL axis) Minimum and Maximum AZ=0.05 deg/sec EL=0.25deg/sec

24 Travel Limits Hardware and Software Limits for

1. Azimuth CW, CCW 2. Elevation UP, DOWN

25 Polarization Travel +/-90 deg CW and CCW motorized Remote & Manual Control

26 Pointing errors(RSS Peak) Max. 1/5th of 3dB beam width at operational wind velocity and occasional gust

27 Tracking errors(RSS Peak) Max. 1/10th of 3dB beam width at operational wind velocity and occasional gust

28 Angle display Resolution 0.001deg in AZ and EL 29 Monitoring & Control Local/Remote (Ethernet with TCP/IP Protocol) 30 Pressurization 9 to 35 g/cm2, Nominal

31 Pressurization Leakage Rate 200cc / Hour, Max

32 wind Velocity Operational: 70kmph, Min Survival (on stow): 200Kmph, Min

The vendor shall provide the best possible Tracking and pointing accuracy values. The Vendor is encouraged to quote the best technology available as on-date to achieve the highest performance.

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Station Control Computer

KU Band Feed & LNA System

Antenna Tracking System

Down Converter

NTP Time Server

High Speed Fiber Optic

links

SAN Data Storage

QPSK Data Demodulator

Figure 1 Ku Band Data Reception System for GISAT

Data Ingest System

FO links> 1km

Antenna Pedestal room

Control Room

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4 System Description ‘Ku-Band Data Reception System’ consists of Antenna & Feed, tracking pedestal, RF systems, Servo system and Mechanical systems. Complete block diagram of the Data Reception system is shown in Figure 1. The Ground Station shall have Ku-Band G/T 38 dB/0K. The antenna diameter shall be minimum of 9 Mts. to meet the G/T requirements. The Reception system should be capable of receiving vertical and horizontal linearly polarized signals simultaneously in Ku-Band. The operating frequency range for Ku-Band is 10.70GHz to 12.75GHz. All Reception parameters should meet the specifications over the operating frequency range. Tracking in Ku-band where half power beam width is approximately 0.18deg is very critical. Tracking accuracy of the order of 1/10th the 3 dB beam width is required for successful acquisition and tracking of Geo-Imaging satellite. Single channel mono-pulse tracking shall be adopted for efficient tracking. Sufficient care should be taken in realizing the feed and components for better noise figure in Ku-Band. In Ku-band, received signals in each polarization will be QPSK modulated at the data rate of 200Mbps per channel. Ku-Band data reception with single down conversion at 1200MHz IF signal is planned. Data IF will be transmitted from Pedestal to control room through High Speed FO links. Demodulators and Data Ingest systems are planned to be in Control room as per the IMGEOS Configuration. The receive system shall have built-in provision for end-end testing and performance evaluation in the absence of satellite signal. The antenna system shall be mounted on a two axis tracking mount to position the antenna over hemispherical coverage. The system should track the satellite in Ku-Band auto-track mode using single channel mono-pulse technique and program tracking/Step tracking as backup modes. As the beam-width in Ku-Band is very narrow, in the order of 0.18 deg, the mechanical, RF and Servo system design should cater to achieve the desired pointing and tracking accuracies. The system should operate in fully automated environment and it should also have full autonomy to meet any contingency requirements. In view of the criticality involved in pointing/tracking requirement, vendor can suggest better technology/multiple options to meet these specifications for better performance. The Antenna system pedestal shall be designed to withstand heavy winds, earth quakes, vibrations etc.

5 RF Systems RF Systems comprises of Antenna & Feed systems, Feed electronics, Down converters, Tracking receiver, High Speed Fiber Optic Data links and Data Demodulators. Highly reliable LNA system with low noise temperatures to be provided for better gain. To provide Wideband corrugated horn for optimum gain and side lobe performance, also mode coupler for precision satellite tracking. To meet the V & H polarization requirements a Polarizer is required for the purpose.

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5.1 Antenna & Feed System The Cassegranian Antenna system shall have main parabolic reflector and a hyperbolic sub reflector with Ku- Band feed. The diameter of the antenna shall be more than 9mts, Antenna system shall have minimum 38 dB/0KG/T value in Ku-Band at 200Elevation. Surface accuracy should be equal to or better than 0.3mm on the main reflector and 0.15mm on sub-reflector. Waveguides shall be used to achieve low loss in Ku-Band feed. A Low Noise Amplifier with better than 65dB/0K noise temperature shall be used to meet the specified G/T Ku-Band feed shall have the capability to receive data simultaneously in both vertical and horizontal polarizations. Feed shall have the capability to track in any one of the polarization in Ku-Band. Precision photogrammetric alignment of the reflector at the expected operating angles for superior performance is required. Monopulse Auto tracking system is required to maximize system availability in adverse weather conditions.

5.2 Down Converters Data signals shall be Down Converted from Ku-Band [10.7GHz-12.75GHz] to 1.2 GHz Frequency (IF) using single stage down conversion. The RF Signal shall be down converted for two channels, one for each polarization. All RF components in the receive chain should be suitably selected to handle the required IF frequency of 1.2 GHz, with data rate of 200 Mbps. These sub systems can be placed near to the feed to reduce the cable loss. Ku-Band Data down Converter outputs in pedestal are fed to Fiber optic link to transmit the Data IF to the QPSK Demodulator in the Control Room, Demodulator Output is fed to the Data Ingest system and then the data is driven to the Storage Area Network. Ku-Band Tracking Down-Converter shall have built in synthesizer to configure the tracking frequency. The output of the tracking down converter shall be the input to the tracking receiver, which is tunable to required tracking frequency. Inputs from down converters are fed to tracking receiver where delta errors for Ku-Bands are generated. The down converter specs are given below in Table 2.

Table 2 : Down Converter Specifications

Parameter Specification

Input Frequency 10.7 GHz -12.75 GHz.

Input dynamic range -10 to -90dBm

No.of Channels 3 channels ( Tri-redundant) L.O Signal Built-in Synthesizer L.O range 9.50- 10.23GHz Final IF 1.2 GHz Conversion Gain 25 dB +1 dB Resolution 1KHz Harmonics < -20dBc

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Spurious <-70dBc Stability 1X10-10 L.O Phase Noise -110 dBc /Hz @10KHz offset L .O. Output Power +7dBm Remote Interface TCP/IP Input /Output

Impedance 50 ohms

Input return loss better than 14 dB

Output return loss better than 18dB I/O Connectors SMA (F)

5.3 Fiber-Optic Link interface: Vendor shall supply the required high speed Fiber Optic (FO) channels from DRS Antenna to Control room for a minimum distance of 1 km or more depending upon requirement. All data signals shall be routed through FO links from DRS Antenna to control room. Trench for laying FO cable will be provided by NRSC/ISRO. The 12 core FO armored cable, Light interface units and F.O Transmitter/Receiver modules are to be installed at both ends.FO links for Data and Antenna control computer shall be through separate FO cores.The transfer of data and other utility signals from DRS system in pedestal to control room is proposed at a distance of more than 1 Km using all weather proof 12 core armored cable. At pedestal end and control room end Light Interface Units(LIU) with 24 ports to be provided. Minimum of 10 FO transmitter/Receiver pairs with Bandwidth ranging from 1MHz to 3.5GHz compatible with APC /SC/FC connectors are to be provided for FO link connectivity.

5.4 QPSK Data Demodulator:

Table 3: QPSK Data Demodulator Specifications

Parameter Specification

Input Frequency 1.2GHz / 720 MHz (selectable) for two chains

Acquisition range Programmable up to+/- 1 MHz

VSWR <=1.5 Dynamic Range -10 dBm to –50 dBm

Acquisition Time < 300 msec

Demodulation modes

BPSK/QPSK/UQPSK/8PSK Selectable

Digital Filtering : Filter Type FIR, symmetrical up to 60 taps, programmable Response Raised cosine, root raised cosine(programmable roll-off factor),Gaussian ,

User defined characteristics in ASCII file Sync. Threshold Eb/No better than 3 dB PCM Minimum Data Rate 10 Mbps for all demodulations per chain

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Maximum Data Rate as given below :

For BPSK Modulation: 200 Mbps (1X 200 Mbps) for each chain simultaneously

For QPSK Modulation: 400 Mbps (2X200 Mbps) for each chain simultaneously

For 8PSK Modulation: 600 Mbps (3X200Mbps)for at least one chain

External Inputs 720 MHz / 1.2GHz IF – 1 & IF-2 Connector : SMA(F) Input Impedance : 50 Ohms

Constellation & Spectrum Viewing

To be provided

Monitor (M) & Control (C)

1. Input Frequency(M,C)

2.Acquisition Range(M,C)

3. BPSK/QPSK/8PSK Demodulation Schemes (M,C)

4. Loop BW (M,C) 5 AGC data (M)

6. Input level (M)

7. Demodulator Lock Signal (M)

8. Eb/No (M)

9. IF Level (M)

10.IF input port selection(M,C)

Bit Synchronizer and Data decoding :

PCM Input Codes NRZ (L, M, S) Selectable

PCM bit rate

10 Mbps to 600 Mbps at Viterbi/RS/LDPC decoder input ( bit synchronizer output) fully programmable with Bit Rate step size 100 bps BPSK(1 X 200) Mbps QPSK(2 X 200) Mbps 8PSK(3 X 200) Mbps

Acquisition Range ± 0.1 % of the symbol rate or better

Differential decoder

a) As per equation given below for QPSK

b) Twenty three other possible equations

Sync. Threshold Eb/No better than 3 dB

Bit sync Coasting Shall be able to hold lock for data containing 128 bits (for NRZ type) of continuous zeros or ones.

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PSK Demod/Bit sync BER performance

<2 dB of theoretical curve

a) Phase ambiguity resolution

Automatic

b) Differential Decoding

Enable / Disable

Single, Dual Viterbi Decoding (CCSDS-131-0-B-2 Aug 2011) (Viterbi decoding puncturing from SAC)

LDPC code, CCSDS 131.1-O-1, September 2007/ CCSDS 131.0-B-2 Aug 2011).

LDPC 1/2 Decoding (1024,2048) LDPC 1/2 Decoding (4096,8192) LDPC 7/8 Decoding (shortened (8160, 7136)

TCM (CCSDS 413.0-G-2) / CCSDS 401.0-B July 2011 Decoding

External Output

Bit Sync Outputs: Both clock and Data after Viterbi, differential decoding :

Data Format: NRZ-L

Level : ECL interface Additional LVDS interface shall be quoted as an option.

Connector : As Specified in Table-5

Impedance: ECL Standard , Additional LVDS interface shall be quoted as an option.

Clock Polarity : Normal/Inverted

Data Polarity: Normal/Inverted (I,Q)

Swap : I/Q

Data Output Interface

TCP/IP Ethernet LAN - Real-Time streaming

Data Output Format

Data formats shall be provided by the party and obtain clearance

Ethernet Ports Dual Gigabit Ethernet Ports

External Input Frame Sync Inputs: Both clock and Data (LVDS) Additional ECL interface shall be quoted as an option.

Clock Polarity : Normal/Inverted selectable

Data Polarity: Normal/Inverted (I,Q) selectable

BER on PN Sequence

Monitor (M)& Control (C)

1. Bit rates (M,C)

2. PCM input codes (M,C)

3. Bit sync Lock status(M)

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4. Loop BW (M,C)

5. Eb/No (M)

6. Data , Clock Polarity Selection(M,C)

7. Lock Status (Viterbi, RS): (M)

8. Quality byte indicating F.S errors(M)

9. BER Display for RS,LDPC,TCM,Viterbi Decoder(M)

10.Viterbi decoding include/exclude(M,C)

11. Viterbi decoding Error status(M)

12. Viterbi decoding selection(M,C)

13. LDPC decoding include/exclude(M,C)

14. LDPC Code selection(M,C)

15. DPC Decoding Error status(M)

16. TCM Decoding include/exclude(M,C)

17. TCM Code Selection (M,C)

18. IF input signal level (M)

19. Carrier lock status (M)

Table 4: Functional Specifications:

Feature

1. Provision should exist for hard and soft decision for channel decoding 2. BER Evaluation 3. BER Evaluation for external base band input 4. CCSDS compliant decoding (Viterbi, LDPC, TCM), ASM detection logic

General Specifications for QPSK Data Demodulator, Chassis and Housing Unit. Parameter Specification and Compliance Power: 230 V + /- 10%, 50 Hz +/- 2Hz, single phase Power Cord: Connector 3-Pin Plug as per current Indian standards (BS-546 Standard) Dimension: 19” Standard Rack mountable, Maximum 5U Size, Maximum Depth 710 mm Operating temperature: 10 to 40 deg C, Max. Humidity 80% Storage temperature: -20 to 60 deg c System Software And Upgrades: All the Software required for the system shall be loaded and delivered along with the system. A soft copy of the software on CD shall also be supplied along with the system. Software upgrades up to warranty period shall be given without extra cost.

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Table 5: External inputs and Outputs details: Sl. No

Input/ Output

Description Connector

1 Input IF input to HSDRS (720 MHz and 1200 MHz selectable) for Chain1

SMA-F

2 Output Bit sync output after Viterbi, differential decode—I for Chain1 ECL(+,-) Interface On SMAF LVDS (+,-) Interface On SMAF/ RJ-45/DType Connectors

3 Output Bit sync output after Viterbi, differential decode—Q for Chain1 4 Output Bit sync output after Viterbi, differential decode—I+Q or C for Chain1 5 Output Bit sync output after Viterbi, differential decode—I Clock for Chain1 6 Output Bit sync output after Viterbi, differential decode—Q Clock for Chain1 7 Output Bit sync output after Viterbi, differential decode—I+Q Clock or

C Clock for Chain1

8 Input Data for Frame/RS decoder input --- I for Chain1 ECL(+,-) Interface On SMAF LVDS (+,-) Interface On SMAF/ RJ-45/DType Connectors

9 Input Data for Frame/RS decoder input --- Q for Chain1 10 Input Data for Frame/RS decoder input --- I+Q or C for Chain1 11 Input Clock for Frame/RS decoder input --- I Clock for Chain1 12 Input Clock for Frame/RS decoder input --- Q Clock for Chain1 13 Input Clock for Frame/RS decoder input --- I+Q Clock or C Clock for Chain1

14 Input IF input to HSDRS ( 720 MHz and 1200 MHz selectable ) for Chain2 SMA-F or N-Type(F)

15 Output Bit sync output after Viterbi, differential decode—I for Chain2 ECL(+,-) Interface On SMAF LVDS (+,-) Interface On SMAF/ RJ-45/DType Connectors

16 Output Bit sync output after Viterbi, differential decode—Q for Chain2 17 Output Bit sync output after Viterbi, differential decode—I+Q or C for Chain2 18 Output Bit sync output after Viterbi, differential decode—I Clock for Chain2 19 Output Bit sync output after Viterbi, differential decode—Q Clock for Chain2 20 Output Bit sync output after Viterbi, differential decode—I+Q Clock or

C Clock for Chain2

21 Input Data for Frame/RS decoder input --- I for Chain2 ECL(+,-) Interface On SMAF LVDS (+,-) Interface On SMAF/ RJ-45/DType Connectors

22 Input Data for Frame/RS decoder input --- Q for Chain2 23 Input Data for Frame/RS decoder input --- I+Q or C for Chain2 24 Input Clock for Frame/RS decoder input --- I Clock for Chain2 25 Input Clock for Frame/RS decoder input --- Q Clock for Chain2 26 Input Clock for Frame/RS decoder input --- I+Q Clock or C Clock for Chain2

6 Antenna Control Servo System

6.1 System description The required antenna control servo system block diagram is illustrated in Fig.1. Broadly the system can be divided into the following sub systems.

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Remote Antenna Console (RAC)

Antenna Control Unit (ACU)

Brush less DC servomotors.

Suitable servo drive amplifiers.

Encoder boxes with angle sensing transducers and limits.

Drive electronic interface including interlocks and drive related processing.

Network Elements

6.2 System operating modes The Antenna Control servo system shall have extensive operational modes to meet the antenna requirements for orbiting satellites. The system shall have two operating control environments. One is “Local mode (operator control)” from Remote Antenna console (RAC) at Control room or Antenna Control Unit (ACU) at Antenna pedestal room and another is “Remote mode” via Station Control Computer (SCC) system from Earth station control room. The system shall support all operating modes, which are described below.

(i) STANDBY MODE:

Standby mode stops the antenna, engages the brakes, and inhibits the drive amplifiers. Once in standby mode, the system needs to be commanded into another operational mode either locally or remotely. While in standby, the ACU will continue to monitor status, alarms and display them in the status display. (ii) SLEW RATE MODE:

In this mode the antenna is continuously moved at a constant rate (selectable) with position loop control in both axes independently. Slew mode allows the user to slew the antenna at variable speeds in either Azimuth or Elevation. The azimuth and elevation axes can be positioned to any angle, and at any rate from approximately 0 to 1 deg/sec, within their specified operational travel limits. (iii)MANUAL MODE:

In this mode the Antenna Control System moves the antenna by the command angle generated by a hand-wheel positioned near the ACU/RAC. Alternatively, the antenna shall be controlled up/down by arrow keys of the keyboard allowing step response around the current position. The step value (0.01, 0.1, 0.5, 1.0, deg) is programmable independently for AZ and EL axes. If the specified angles are within the limits of the azimuth and elevation axis, the pedestal immediately points the reflector to the requested angles. The antenna angle is digitally compared to the command angle to generate position error.

(iv) AUTO TRACK MODE:

This mode is one of the main operational modes of ACU. In this mode the ACU controls the antenna to point the target accurately with the error signal produced by the mono pulse tracking receiver.

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The Auto mode augments the manual or program mode by switching to auto track mode when the tracking receiver locks on the downlink signal. Auto Enable monitors the selected tracking receiver (Ku-band) AGC and ACQUIRE / LOSS status. When the received AGC is greater than the acquisition threshold, the receiver status indications become valid and Auto Track Enable is selected, then ACU switches to the Auto track mode. A good tracking signal is required to maintain Auto track mode. The ACU monitors the Ku-Band tracking receiver AGC lock status. (v) PROGRAM MODE:

In this mode, the present antenna Azimuth and Elevation angles are compared with the pre-determined satellite look angles with respect to time, and position errors are generated corresponding to the angle difference. Thus the antenna is servo controlled on the angular positions received before satellite tracking either from the Remote computer (RAC) or by the look angles generated by the ACU based on the satellite ephemeris data. (vi)DESIGNATE MODE:

The designated preset memory allows the operator to save at least 25 targets (Such as satellite, bore sight, stow lock etc.) configurations. A target configuration includes Az and El position. The ACU shall have the following databases to achieve the above function.

Pointing database that allows the user to enter an object based on its azimuth and elevation positions.

(vii)COMAND ANGLE MODE:

In this mode, the user will feed the required AZ & EL command angles through GUI interface, and the servo system must position the Antenna to the commanded AZ & EL angles at a pre-determined speed taking care of cable wrap position.

(viii) AUTO SEQUENCE MODE:

In this mode the user can stack different modes on top of each and designate thresholds and boundary conditions for transitioning from one mode to the next. The initial pointing mode and the priority of stacking the modes shall be user programmable. Various configurations of stacking of modes are possible depending upon the mission requirement. For example the operator may stack modes in the following manner. Manual modeProgram mode Auto TRACK MODE

Operationally the user can pick an initial pointing mode such as Program mode or manual mode. The ACU would position the antenna in azimuth and elevation based on the angles generated from ephemeris data or manually loaded look angles. Once AGC level exceeds the Acquisition (Ku-band) Auto receiver threshold, the system begins to Auto-track on the Ku-band signal (Acquisition Auto). If the signal drops below the threshold level the system backs down to the previous mode, at any stage of the “automatic-acquisition and tracking process”. The operator can set the signal thresholds of the tracking receiver for transitioning fromProgram Tracking to Ku-Band Auto Tracking. At any time in this process, the signal level exceeds the pre-defined threshold; the system shall begin the Auto track.

(ix)SUN/MOON/STAR TRACK:

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The ACU Mode-Display-window includes both Sun,Moon and Star Track modes. When Sun or Star Track is selected the antenna is commanded to track the sun or the star using an ephemeris program that is resident in the ACU. These modes are useful for G/T measurement, alignment and system calibration. The ACU shall have the following databases to achieve the above function.

Star Database that is predefined with the most common stars.

Sun.

Moon.

6.3 System safety interlocks The System shall have facility to manage the following interlock functions for the safety of the antenna and control the overall system operation sequentially. Following are the interlock functions to be incorporated into the system algorithms/hardware circuits. (i) CONTROLLER (ACU) ON/OFF

This ensures that all the elements of Controller such as PC, monitor, and Control Electronics are powered ON. ACU OK indicator ensures that the ACU is ON and communicates with RAC.

(ii) ANTENNA DRIVE UNIT (SERVO DRIVE) ON/OFF

This ensures that elements of Antenna Drive Unit (positioned at the antenna room) such as DC power supplies, Drive Amplifiers, Drive Electronics, and Exhaust fans in the Antenna Drive Unit are powered ON.

(iii) EMERGENCY STOP

Emergency stop switches are provided at the Antenna pedestal, ACU and RAC to stop the antenna movement abruptly, in case of any emergency situation or for maintenance of the Antenna Control Servo System. The interlocks shall trip the AZ/EL axes. (iv) AZ. AXIS ON/OFF

Az. axis can be ON only when at least one motor and corresponding Drive amplifier is ready for azimuth axis movement subject to normalcy of ACU and ADU (Antenna Drive Unit) control electronics. Other pre conditions of interlocks include Emergency stop not activated and stow is in released condition.

(v) EL. AXIS ON/OFF

El axis can be ON only when at least one motor and corresponding Drive amplifier is ready for elevation axis movement subject to normalcy of ACU and ADU control electronics. Other pre conditions of interlocks include Emergency stop not activated and stow is in released condition.

(vi) AZ. STBY/EL. STBY

As explained in the modes of operation, stand-by status is a pre-condition for antenna operation in any of the tracking modes described. The stand-by interlock status ensures that

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all the alarm conditions are non-existing and system is ready to activate the drive amplifiers and motors.

(vii) AZ. AND EL. MOTOR BRAKE RELEASE

The servomotors are equipped with built in fail-safe electro-magnetic brakes. The brakes shall be released first, before applying the rate command/control enable signal to the amplifiers in all operating modes. The brakes will be applied when the system is kept in standby mode. (viii) ANTENNA TRAVEL LIMITS (Pre-limit and limits)

For the safety of the antenna and interface cables, the antenna movement is restricted to safe operating limits. Limit switches fixed on the antenna drive pedestal will operate and signals from these switches are fed back to ACU/Drive interlocks.

i) HARDWARE TRAVEL LIMITS:

a) PRE-LIMITS: As the name suggests when the pre-limit reaches, it is an advance notice to the operator that the antenna is in the limit zone and close to final limits and the antenna speed is reduced. Respective Pre-limit indication flashes on the screen and the maximum rate input will be limited to 1.0 deg/sec. b) FINAL LIMIT: The antenna will be stopped at this point and further movement is restricted when the final limits are reached. Respective Limit indication will be displayed on the screen with audio alarm. To come out of the limit condition the operator has to give reverse command depending on the actual limit direction.

ii) SOFTWARE LIMITS AND PRE-LIMITS:

In addition to the hardware switch arrangement for the travel limits, the ACU will have software limits. Nominally the antenna movement will be restricted within these limits by monitoring the angle data directly. On reaching the set limits (programmable) the antenna cannot be moved further in that direction and allows movement in the reverse direction only. The pre-limit function is same as hardware pre-limits function as explained above.

All the software limits & Pre-limits shall be field programmable.

(ix) AZIMUTH /ELEVATION DRIVE AMPLIFIER READY STATUS

The synthesized drive ready status of the drive amplifier (motor –1 and motor-2) is interlocked with the AZ/EL drive enable command so that the drive amplifier is activated only when the drive is ready and no other faults are existing. Drive Ready is a synthesized status output from the Drive amplifier. (x) AZ/EL SERVO MOTOR OVER TEMPERATURE (Motor-1 and Motor-2)

The thermal cut out switch contacts of the servomotors shall be interlocked with the respective drive amplifier enable command so that the motor is not powered when the motor rotor temperature rises beyond the specified operating limits. The drive amplifier shall be tripped when the motor thermal cut out switch is operated.

6.4 System status display

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The RAC/ACU screen shall show a detailed system status. Following are the parameters to be displayed on the RAC/ACU operating screen. All error messages and system faults, operator prompts, menus etc shall be in plain English or easy to remember abbreviations or mnemonics.

1. Azimuth and Elevation antenna position in deg (0.001 resolutions).

2. AZ and EL command position in deg (0.001 resolutions).

3. Difference between Antenna and Command position in deg (0.001 resolutions).

4. Operation mode.

5. Azimuth limits and pre-limits.

6. Elevation limits and pre-limits.

7. Azimuth and Elevation rates in degrees/sec

8. AZ and EL Drive currents in Amperes.

9. Azimuth Drive system fault status.

10. Elevation Drive system fault status.

11. Tracking system parameters like Signal strength, lock status and Tracking errors

for two auto track chains (Ku-band).

12. Graphical representation of Tracking receiver AGC and Tracking errors.

13. Universal Time (ddd: hh:mm:ss) and date.

14. Local time (hh:mm:ss).

15. Tracking aids (Bull’s eye etc)

16. ACU Active/hanged status.

17. Position loop lag errors in graphical form (Auto, Program and CDM).

18. Satellite Pass summary.

6.5 System functional requirements

The Antenna Control Servo system shall meet the following functional requirements.

Control the antenna in various defined operational modes.

Steer the antenna at the maximum specified rate and acceleration in Azimuth and

Elevation axes.

Interlock functions for sequencing operations under various operating modes and

provide safety of Antenna, drive Amplifiers and brush-less DC servo motors. A hard-

wired EMERGENCY STOP switch shall be provided on the front panel of RAC and

ACU.

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Logging of angle data and transmission to station computer as per the specified

format and rates.

LAN interface - shall support TCP/IP network configurations.

Reception of Satellite ephemeris from station computers and generation of look

angles locally.

Automatic down loading of look angles from Station Computer/Remote computer.

24 x 7 Automatic operations..

Digital compensation.

Automatic selection of Bandwidth/gains in all tracking modes (Auto, Program) based

on user defined options through configuration files.

Automatic gain adjustment of Auto loop with error slope changes (Ku-band tracking,

single or Double motor).

M&C functions, Status transmission to Monitoring and Control System in the

specified format and interval

Graphic screen based display of Antenna angles; command angles; position error and

satellite pass support details and display of all other system parameters and alarms.

Configuration control for important software controls like encoder bias, time offset,

adaptive bandwidth selection i.e. wide/narrow, loop gain, angle offset, data rates,

Single / Double motor drive etc.

Counter torque drive configuration with torque bias (typically 20%) and fade out

adjustment (field configurable as per requirement).

Hardware and software antenna coverage limits.

Interlocks for all alarm features, Motor brakes, Stow lock, Emergency stop, cable

wrap indication etc.

Built in Test and evaluation and system diagnostic functions.

Auto Acquisition and tracking methodology, using sequencing/stacking of operational

modes. The priority of modes shall be user programmable.

Tracking-aid display (Bull’s eye)

Servo Compensation and Evaluation Tools.

6.6 System Specifications

Table 6: ACSS Specifications SL NO Parameter Description

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1. Position Display Resolution 0.001 deg or Better

2. Programmable Control

Parameters

PID/LQG Control Gains and Torque Bias for Single/

Dual Drive Configurations.

3. Position Loop Bandwidth 0.1 to 1.0 Hz typically Field Programmable for BW for

single/ dual drive configurations.

4. Rate Loop Bandwidth 5.0 to 10.0 Hz Field programmable for single/ dual

drive configurations.

5. Operating Modes Standby, Ready, Slew, Manual, Program, Designate,

Adapt Track, Ku-Auto, Step, Slave modes.

6. Type of Control System Type I/Type II Closed Loop Position Control

7. Tracking Modes Ku-Band Auto track and Program Track

8. Acquisition Modes Auto sequence mode

9. Other modes/Features Sun/Moon/Star track, Event Log, Tunable S/W servo

compensators, Built in GPS Receiver with better than

1ms accuracy, IRIG A/NTP server time plug in

10. Drive Configuration

Two Motor Counter-Torque (Torque Bias)

11. Type of Motor Brushless AC Servo Motor with Resolver Feedback

and Built in Brake.

12. Type of Drive Space Vector PWM Drive compatible to above Motor

13. Axis Supported Azimuth and Elevation

14. Digital Controller

PID ,LQGor any other advanced Control Schemes

15. Offsets Adjustments Azimuth, Elevation and Time

6.7 Antenna Control Unit

Servo Controller must be a software configurable digital controller for implementing precision closed loop servo control system for two axes. It must implement the functions of Position loop through position feedback and torque bias function.

Table 7: ACU Specifications

SL No Parameter Value

1. Tracking modes Ku-Band Auto Track and Program Track

2. Manual Modes Standby, Manual, Step, Slew, Adapt, Designate & Command

Angle

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3. Axes supported Azimuth and Elevation.

4. Digital I/O channel 48 OPTO Isolated.

5. Analog – Digital

Channels

12 Channels with ± 10 Volts Differential Input and 16 Bit

Output

6. Digital – Analog

Channel

10 Channels with 16 Bit Input and ± 10 Volts Output

7. ACU/RAC PC Intel Core i7 Processor at 2.8 GHz or above

8 GB RAM and 4MB Cache, 1TB HDD or Above

1x4GB Solid state DD, 1 x 52x DVD drive or

above Shall support external CRT monitor

simultaneously. Wireless keyboard and Mouse

for local operation. Minimum one or two user

slots shall be free after system requirement. I/O

ports 2 serial, 4 USB (2.0 & 3.0),

1 Centronics compatible parallel LAN ports

2numbers of RJ 45,with 100/1000 Base –T

8. Display Monitors

(2 nos)

21” TFT LED Display with a resolution of 1024 x

768 or better

9. Operating System Windows 2003 server operating system or better

Windows server OS

10. Position Display

Resolution

0.001 deg or Better

11. Programmable

Control Parameters

PID/LQG Control Gains and Torque Bias for Single/

Dual Drive Configurations.

12. Position Loop

Bandwidth

0.1 to 1.0 Hz typically Field Programmable for BW for

single/ dual drive configurations.

13. Rate Loop

Bandwidth

5.0 to 10.0 Hz Field programmable for single/ dual

drive configurations.

14. Operating Modes Standby, Ready, Slew, Manual, Program, Designate,

Adapt Track, Ku-Auto, Step, Slave modes.

15. Type of Control

System

Type I/Type II Closed Loop Position Control

16. Tracking Modes Ku-Band Auto track and Program Track

17. Acquisition Modes Auto sequence mode

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18. Other modes

/Features

Sun/Moon/Star track, Event Log, Tunable S/W servo

compensators, Built in GPS Receiver with better than

1ms accuracy, IRIG A time plug in

19 Safety and EMI Shall meet the standards UL/CSA/TUV and FCC/VDE

Class A

6.8 Required Features & Functions of ACU

Software Configurable servo loops

Real time data logging, fault indication and event logging

Provision to give offsets to Azimuth, elevation and time during Real time

Polarization control

Time Synchronization to be better than 500 micro seconds

Programmable Software and Hardware limits

Self-Test Diagnostic Tools for all Sub Systems

Antenna Brake Protection circuit.

Safety Limits and Interlocks

The antenna control software should have the capability to track the satellite in real-time in Auto track / step track / Adapt track/program track mode. The required functions of the Antenna Control software are:

GUI to display the station configuration

Positioning the antenna to satellite lookup angles

Automatic configuration of the sub systems

Control system software tools for modeling, estimation & compensation of

systematic errors of Antenna mount, Antenna droop etc.,

Dynamic friction compensation

Real time monitoring and data logging.

Implementing different tracking modes

Implementing different acquisition modes

Utilities to carryout different servo tests like velocity and acceleration tests,

Gradient measurements, S curve, step response etc.

Data logger to monitor and log different engineering parameters of ACSS system.

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Display of safety limits and Interlocks.

Utilities to track Sun/Star/Moon.

6.9 Remote antenna console (RAC)

The RAC shall be a 19” Rack mount Industrial PC with 24” TFT LED display monitors 2nos (HP or Dell), wireless keyboard and mouse. The RAC shall be configured with the M&C Windows-based operator interface providing local GUI operation as well as the Servo Test & Evaluation Toolkit allowing for comprehensive diagnostic and performance monitoring. The RAC provides the interface to remote operations via the local area network (LAN). Refer block Diagram.

The PC Hardware/Software specifications will be identical to ACU PC.

6.10 System control software and software tools The software shall broadly have the following packages. The software shall be based on latest Windows/LINUX server Platform and provide a suite of system monitor, control and diagnostic tools.

1. ACU M&C windows application software

2. RAC M&C windows application software

3. Instrumentation Software: Consists of Test and Evaluation software

The antenna control software should consist of TCP/IP interface to facilitate remote

monitoring and control of servo system.

6.11 ACU M&C windows/LINUX application software:

This shall be the real time servo software that resides in the ACU. This software shall provide servo loop compensation, status & control processing, interfaces to the ADU, remote interface to RAC and front panel software interface. All inputs and outputs are configurable via a setup file local to the controller or down loaded via the remote interface.

Application Software shall run under Latest Windows/LINUX or higher server Operating

system and shall have the following features.

User friendly and intuitive graphic user interface, remotely operatable.

Extensive use of digital signal processing.

Upgradeability and flexibility.

Dual-Axis Torque bias control (Azimuth & Elevation).

Digital servo compensation.

Data logging.

Generation of look angles based on satellite ephemeris.

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Remote down loading of Time tagged Satellite look angles.

Built in test functions.

Self Test

On-line help system.

Customization facility for control parameters through configuration files.

6.12 RAC M&C windows/LINUX application software:

RAC M&C software shall be the primary interface for operators, supervisors and administrators to control and configure the antenna.

RAC M&C software shall provide the latest Windows/LINUX or higher server based operator interface for the control and monitoring of antenna system, down converters, tracking system and data demodulators. The software provides local control of the antenna at the given site. The remote M&C interface allows for remote control from a central site via M&C system. The software features shall include:

Intuitive, graphical monitor & control.

Satellite database with ephemeris.

Look angle generation

Monitoring and controlling functions.

Configurable alarms and status via initialization files.

Multiple window interface for system configuration, monitor and control.

Flexible system configuration.

Tracking Aid Display (Bull’s eye etc)

6.13 Instrumentation software/diagnostic tools The instrumentation software shall establish the initial antenna performance baseline. During the Periodical performance evaluation and Test & Evaluation activities, the tests can be repeated again and compared against the baseline. Following test capabilities shall be incorporated in this software tool. The resulting test data is plotted on software based strip chart recorder (Data Logger) and saved. Provision for printer/plotter interface shall be made available.

1. ERROR SENSITIVITY (S-Curve) TEST: To plot position error generated in Ku-

Band auto track mode

2. STEP RESPONSE TEST: The step response test executes tests to evaluate the

responsiveness and stability of the antenna servo system by recording the position/rate

of the antenna verses time in various operational modes. Step response of Auto track

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can be performed by pointing the antenna to the bore site source. Rise time, Settling

time, % of overshoot and bandwidth shall be computed, logged and displayed.

3. VELOCITY/ACCELERATION: The velocity and acceleration test is designed to

measure the maximum velocity and acceleration of the antenna servo system.

Velocity and acceleration measurements can be made for both dual and single motor

cases.

4. SATELLITE TRACKING PLOTS: To record, display and store Antenna Azimuth/Elevation position/velocity/Acceleration vs time during the satellite pass.

6.14 Antenna Motor & DriveSystem Digital Drive Amplifiers must be high efficient 3 phase Space Vector PWM IGBT based power amplifier to drive the brushless AC servo motor. There are total four power amplifiers each axis will have two power amplifiers. Servo Controller with built in power supply and Ethernet interface for configuration, control & monitoring of current, velocity, fault & status indication. Suitable drive amplifier with the following features is required.

Integrated Power Supply and controller with all the protection circuits.

Dynamic brake facility.

Configurable for Velocity / Torque modes.

Programmable control parameters.

Potential free contacts for interlocking the drive amplifier.

Resolver/encoder interface

Ethernet interface for remote monitoring & control

Provision for monitoring current, faults, status etc.,

Protection features

Table 8: Brush less ac servo motor specifications

Make Leading Manufactures like ABB/Parker/any other Proven international Brand

Stall Torque

Suitable to the Antenna load as per system specifications for tracking Geo-Satellite

Peak Torque Rated Speed

Rotor inertia

Insulation Class H Protection Thermal sensing switch on stator winding. Cut off @ 150°C Attachment Resolver Built in brake Suitable to the Motor

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Cooling Natural air cooling. (No Blower) Connection Flange mounting, standard type Drive shaft Standard type with key Protection IP 65 class with oil seal Interface Through MS Circular/Mil Connectors.

6.15 Drive Amplifier Specifications Compatible with the above Brushless servo motor. All digital drive designs are PWM controlled converter with 3-Ø-power configuration using IGBT or any advanced design.

Integrated Power Supply and controller with all the protection circuits with Dynamic braking facility.

Table 9: Drive amplifier specifications

Make ABB/Parker/ Any other proven international brand Drive Input voltage 415V, + 10%, 3-Ø, 50Hz or Standard Indian Power

Supply. Continuous current

Suitable to the Motor selected Peak current Power Loss at Continuous Current Efficiency 95% Configuration Modes Velocity / Torque Drive Amplifier to Motor connection

As per the requirement at site.

6.16 Antenna Drive Unit The ADU houses the BLAC servo drive unit that includes 4 Pulse Width Modulated (PWM)

servo amplifiers to drive the azimuth and elevation AC Brush-less servo- motors. The drive unit operates as a velocity loop with torque bias set by the ACU to minimize

backlash and maximize pointing and tracking accuracy. The torque bias parameters are configurable in the ACU to optimize performance.

The ADU also provides power and interface points for the discrete I/O antenna points. The ADU includes all the required power supplies for Drive amplifiers, drive electronics,

switches, stow pins, alarms and motor brakes. These status points are controlled and monitored by the ACU.

The ADU shall be built with RFI shielded enclosure. The ADU is equipped with

the following sub systems

Power switching and control

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EMI/EMC Filtering Chokes

DC power supplies, control circuits

Current limiting fuses, Circuit Breakers.

Pulse Width Modulated (PWM) servo amplifiers.

Transformers, dynamic braking resistors

Line reactors

Emergency stop etc.

In Addition to above, additional subsystems/components may be added to meet the

requirements.

6.17 ADU Functional Specifications:

Controlled power up/ down sequencing

ON / OFF control for Each motor drive

Single motor drive operation in the event of motor / drive failure.

Interlock device on the door.

Emergency stop switch on the front door of the drive unit.

Built in power line conditioner with over load protection for RFI/EMI suppression, at

the power input point. Additional heat sink for dynamic braking resistors.

Easy access to remove drives when faults are detected.

Interlock device on the door.

All contactors and brake coils shall have transient suppression devices.

All relays shall be protected with flywheel diodes and LED indicators

Local operational panel (Plug in control module) with limited control options as given

below.

Azimuth axis ON/OFF.

Elevation axis ON/OFF.

Azimuth Mode ON/OFF.

Elevation Mode ON/OFF.

Emergency ON/OFF

6.18 Mechanical Aspects:

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Proper cooling arrangement with built in air filters and exhaust fans.

Physical dimensions and layout addressing all the aesthetic and human engineering

aspects, for elegance and operator comfort.

All the rack mounted sub systems (if any) shall have sliding arrangements providing

easy access for maintenance.

Cable Entry Duct & Connector I/F Panel

Standard cable entry ducts and power distribution systems.

Proper grounding and grouting arrangements shall be made.

6.19 Encoder Box

The Encoder box shall house absolute rotary shaft encoder for antenna position sensing,

internally connected with anti-backlash gear train. The input to the encoder box shall be

derived from the antenna Azimuth/ Elevation slew ring bearing having internal gear teeth.

Table 10: Absolute rotary shaft encoder specifications

No .of turns single turn

Absolute position Values 4194304/revolution (22 bits)

Flange Synchro Flange

Data Interface Serial Synchronous Power Supply 5–30 Volts DC 10%

Absolute Signals Pulse, Serial with error detection

Type of Code Grey or Pure Binary, synchronous

Cable Length to ACU 50 mts

Protection IP 67 for housing, IP 66 at shaft inlet

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7 Mechanical Systems:

7.1 Description of the Antenna mechanical system The Antenna mechanical system can be broadly divided into three categories, namely

1. Tracking pedestal (AZ and EL mount)

2. Reflector and Sub reflector assembly

3. Feed system sub assembly

In the proposed Antenna & mechanical system, Reflector dish is mounted on a 2 axis

mount (Tracking Pedestal) which can scan the entire sky. The mechanical system consists

of Aluminum or Carbon reinforced Reflector supporting the Feed and Hyperbolic Sub-

Reflector through a Quadruped/tripod, an Antenna mounting frame attaching the

Reflector to a pair of Yoke arms with Counter weight arms, an Elevation housing

containing the necessary drive system for movement about an Elevation axis between the

horizon to zenith and Azimuth housing containing the drives to achieve required rotation

0 to 180 Deg in Azimuth in Continuous mode to enable pointing the antenna to any GEO

satellite. The Rigidity of the mount, reflector & foundation should be able to provide the

required pointing & Tracking accuracies.

7.2 Mechanical considerations for Antenna Design

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Design aspects: 1. Accessibility, Reliability, Maintenance and fail safe operations.

2. Reduce the weight of the reflector and increased stiffness

3. Antenna deflections are within the limits of pointing error and reflector RMS value at

specified wind loads and operational temperatures.

4. Compact and rigid design of AZ/ELaxis housings.

5. Overall Surface accuracy of the main and sub reflectors.

6. Axis Alignment i.e. Orthogonality between Azimuth and elevation.

7. Structural deformation due to wind, Temperature and gravity. The reflector back up

structure needs to be strengthened. The required Structural stiffness of the reflector has

to be estimated.

8. The individual panel fabrication error to be accounted considering the manufacturing

tolerances in stretch forming process. The field setting errors using photogrammetric

technique should be accounted.

9. Minimum Gear backlash, less thermal deformation of reflector and encoder alignment

directly to the axis shaft to achieve the overall pointing accuracy.

10. The pedestal errors have to be made barest minimum with optimum design and high

precision machining and quality control.

11. Due to high pointing accuracy requirement, high precision fabrication of mechanical

components and sub-assemblies are to be carried. Stringent tolerance specifications are

to be made, measured and accounted properly.

7.3 Structural analysis, design and fabrication details 1. Reflector panels, backup structure (stiffeners) of Antenna system considering operational

wind speed of 70kmph, survival wind speed of 200 kmph and inertial effects of

movements in Azimuth & Elevation directions.

2. Feed cone & wave guides structure.

3. Design check of structural elements for the temperature variations of 00C- 550C for

differential temperature variations of 50C.

4. Design of radial panels with glued stiffeners with durability criteria of adhesive used.

5. Provisions for lightening arrestors, aviation lamps and other functional apparatus.

6. Counter weights required to balance the antenna about elevation axis.

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7. Interface structures like yoke arm, yoke fixing structure, Antenna mounting frame

between the Antenna and Tracking pedestal.

8. Design of suitable gear boxes for AZ and Elevation axis.

9. Design of suitable couplings between gear box and motor including selection of suitable

motors.

10. Design of suitable slewing ring bearings for AZ and EL considering operational and

survival wind load factors of antenna and pedestal structure.

Surface Coatings: All the structural components are to be coated with suitable anti corrosion type of paints and

the technical specifications of the paint used are to be provided.

7.4 Civil works for Antenna Pedestal

1. Basically the civil works activity starts after completion and approval of the Antenna

structural and Mechanical design. 2. Anchor bolts and civil foundation design has to be provided by the vendor. 3. The Antenna structure building design (civil) will be carried by NRSC taking into

consideration of civil structural inputs provided by vendor (Operational & survival environmental conditions like wind, earthquake resistance etc.).

8 List of Ku-Band Data Reception System Deliverables

1. Parabolic Antenna and Ku-Band feed electronics

2. Servo Systems for Antenna control 3. Ku-Band Data and Tracking Down converters

4. Tracking receiver 5. High speed FO link between DRS Antenna and Centralized Control Room (FO cable

minimum of 1km length depending upon site location) with all suitable interfaces. 6. QPSK Data Demodulator.

7. Station Control Computer

9. Reliability & QA requirements

The operational life of the complete DRS Antenna System (including drive, bearings and

other moving parts of the antenna, RFsystems, Servo Sub-systems and control systems) is

expected to be at least 15 years. The DRS Antenna System will be operational24x7 in

automatic mode/remote control mode. Vendor has to suggest the list of spares required for

the proposed system. The redundancy required in all the subsystems shall be provided by the

vendor. Electrical and Mechanical characteristics of proposed Reception system shall comply

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with the (EIA standard) EIA-411-A document. All Sub-Systems should comply with CE

standards. The station will be operating under controlled environment. However the

equipment used shall have the capability to withstand the following environmental condition

complying to IP 65 environmental protection.

Table 11: Indoor Unit Environmental Specifications

SL NO

Parameter Value

1. Operating temperature 10 to +350 C 2. Storage temperature -10 to+650 C 3. Humidity 80% RH non condensing

Table 12: Outdoor Unit Environmental Specifications

SL NO

Parameter Value

1. Operating temperature 0 - 600 C 2. Storage temperature -10 - 650 C

3. Humidity 95% RH @ 400 C with condensation 4. Rain >= 200 mm/Hr

5. Wind Speed Operational Occasional gusting Drive to Stow Survival to Stow

70 KMPH 90 KMPH 100 KMPH 200 KMPH

10. System Installation & Integration

The vendor shall be responsible for installation and commissioning of the Ku-band Reception

System at NRSC locations. Vendor should demonstrate its functionality in its full

configuration at user site for final acceptance. Final acceptance of the system will be done

only after installation at user site in its full configuration.

The vendor is supposed to deliver, install and commission the system within 12 months

from the date of issue of Purchase Order.

11. Programme Clauses

11.1 DELIVERY / SCHEDULE: The two systems will be supplied and installed at

NRSC, Shadnagar, Mahbubnagar District, Telangana in 12 (twelve) Months time from the

date of the Purchase Order.

11.2 WARRANTY: 24 Months from the date of Acceptance at the site.

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The warranty shall cover any material defect, workmanship including SOFTWARE BUGS

are to be fixed if any. For spares supplied, warranty shall be from the date of receipt of these

equipment/stores at NRSC.

11.3 FACTORY ACCEPTANCE TEST: All systems shall go through a mandatory

factory acceptance test either Integrated or Sub-system Level.

11.4 SITE ACCEPTANCE AND TRAINING: ATP will be conducted with NRSC

Engineers. Demonstration of real time satellite tracking in Ku-Band is the responsibility of

vendor. Subsequently On-site/Off-site training will be conducted by the vendor.

11.5 SYSTEM SOFTWARE AND UPGRADES: All the Software required for the

system shall be loaded and delivered along with the system. The soft copy of the software on

CD shall also be supplied along with the system. Software upgrades up to warranty period

shall be given without extra cost.

11.6 SPARES SUPPORT: Shall support spares for this program for a period of 10 years.

11.7 The vendor must have experience of installation and commissioning of Ku-Band

antennas, and also the KU-Band stations (with Monopulse Tracking) installed by the

vendor should have been operational supporting KU- Band data reception for at least one

year.

12. Acceptance Test plan/testing methodology

The system will undergo the acceptance tests as per the mutually agreed test plan at the

vendor’s site (factory acceptance test FAT) as well as at installation site (site acceptance test

SAT) and user validation. The vendor will be responsible to arrange the tests in the presence

of NRSC/ISRO engineers. The tests may be as per the sequence given below with a detailed

test plan and will be finalized latter.

Subsystem level tests at Vendor’s/Manufacturer’s premises

Sub system level test at user site after receipt of the systems

Testing of antenna control and tracking system.

Testing with complete antenna systems

Simulation checks

Testing of the Ground Station with Geo-Imaging Satellite(GISAT) in orbit.

Final acceptance test plan as per NRSC laid down procedures

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Table 12: Acceptance Test plan/testing methodology

S.No

System under test

FAT

SAT Method T-test

D-demonstrate

SPECS

Test procedure

Comments

1 ANTENNA SUB-SYSTEM

a) receive side lobe patterns

b)cross polarization isolation

c)Antenna receive gain

d)system noise temp profile

e) system G/T f) Mechanical

alignment

2 FEED/LNA a) Feed VSWR b) Feed port-port

isolation

c) Feed Cross pol Isolation

d)Feed pressure check

e) Diplexer insertion loss

f) LNA noise temp and gain

3 DOWN CONVERTER

a) Frequency response

4 ANTENNA CONTROLS

a)ACU in process tests

b)Limit switch operation and calibration

c)Emergency stop functionality

d)Pointing and tracking accuracy

e)Resolver alignment

f)Axes Velocity g)Tracking Rx gain

response

h)Polarisation control and functionality