Ground Station Design and Requirements for Scientific Data Acquisition of DSP Satellites July 5, 2002 Ma Zhongsong CSSAR

Contents Overview Ground Stations Interface Requirements to VILSPA2 Equipments Delivery Test Instruments Required Site requirement

Overview Background Technical Visit to ESOC & Villafranca Station (June 11, 2001) Minutes of Meeting

DSP Satellites’ Orbits Equator Polar Inclination 28.5 ° 90 ° Perigee 550 Km 700 Km Apogee 63781.4 Km 39000 Km Period 20.9hrs 11.7hrs

Scientific Data Channel Specifications RF Frequency 2287.5MHz Power 7~9W Modulation DQPSK BER ≤1×10-5 Data Rates ＜5000km 5000～15000km 15000～45000km 1024Kbps 128Kbps 16Kbps

Ground Stations CSSAR Ground Station(Beijing) European Ground Stasion(VILSPA2, Spain) Shanghai Astronomical Observatory (Upgrade Required)

CSSAR Ground Station(Beijing) Location: 40°27′37″N,116 °51 ′06 ″E, 99m Antenna: 11.28m Frequency Range: 2200~2300MHz Polarization: LHCP/RHCP/Combined Gain: 45.6dBi G/T: 24.5dB/K@EL=5 ° Pedestal: AZ/EL/Train(Overhead Pass Support) Max. Velocity: EL10°/S ，AZ22°/S Max. Acceleration: EL10°/S2 ，AZ10°/S2 Tracking Accuracy: 0.02 °rms

CSSAR Ground Station Block Diagram

CSSAR Ground Station Upgrades Variable Bit Synchronizer Additional IF Filters in Receivers for Three Bit Rates Real-time Automatic Controller of Data Channel Equipments Multiplexer &Deplexer for Microwave relay channel

European Ground Stasion(VILSPA2, Spain) Location: 40°26.42' N,3 °57.07' W, 664.45 m Antenna: 15m Frequency Range: 2200~2300MHz, 8000~8500MHz Polarization: LHCP/RHCP G/T: 28dB/K(S-Band), 36dB/K(X-Band) Pedestal: AZ/EL Max. Velocity: 15°/S

VILSPA2 Block Diagram

Shanghai Astronomical Observatory Location: 311°05′57″N,121 °11 ′59 ″E, 5m Antenna: 25m Cassegrain Pedestal: AZ/EL(Railway) Max. Velocity: EL0.28°/S ，AZ0.55°/S Pointing Accuracy: 20 ″ rms

Shanghai Astronomical Observatory Upgrades S-Band Feed (Tracking Channel) Servo System (Auto Tracking) Data Channel Equipments Supported by CSSAR S-Band Receiver QPSK Demodulater Data Recorder Test Equipments

Interface Requirements to VILSPA2

Equipments Interface to VILSPA2 70MHz Switch PCM Switch IF 70MHz IF 70MHz Data/ Clock L-Band Down Converter IFMS CDS TMP IF 70MHz Data/ Clock Terminal Test Device IF 70MHz Data Distribution Unit RF 2287.5MHz Data/ Clock Simulator BER Tester PC Data Recorder Data/ Clock Demodulater PC Data Recorder VILSPA2 Instruments CSSAR Instruments

Interface Specifications Base Band (Data/Clock) Code: NRZ-L Level: TTL Bit Rate: 1024/128/16Kbps Impedance: 50Ω Connector: BNC Clock Phase: 180°

Interface Specifications (Continued) Intermediate Frequency (IF) Frequency: 70MHz Level: 0±1.5dBm Impedance: 50Ω Connector: N type

Data Distribution Unit Equipments Delivery Items Quantity 1 Data Distribution Unit 2 Data Recorder 3 RF Simulator 4 Demodulator 5 Terminal Test Device

Test Instruments Required Digital Transmission Analyzer/BER Tester (16K~1.024Mbps Binary Code Support) Spectrum Analyzer (0.1M~3GHz) Oscilloscope (100MHz) Function Generator(0~10MHz)

Site Requirement One 19 Inch Rack for Five 2U Chassis Desk for Two Recorders(PCs) Power Supply(AC220V50Hz/500W) UTC Source (TBC)

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