Portable Satellite Simulator PSS

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The new Portable Satellite Simulator a corner
Stone of the ESA Ground Systems Tests and
Validation Infrastructure
Christian Laroque, Anite Martin Götzelmann,
Anite Carsten Grøn-Nielsen, European Space
Agency Per Jensen, European Space Agency Mauro
Pecchioli, European Space Agency Bryan Tatman,
Satellite Services B.V
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Co-Authors

• Martin Götzelmann
• PSS Project Manager
• Carsten Grøn-Nielsen
• Space Systems Consultant
• System Engineer
• Per Jensen
• Mauro Pecchioli
• Bryan Tatman
• Engineering Manager

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Portable Satellite Simulator (PSS)

• Generic PC based system
• Telemetry processing
• Generate telemetry flow
• Inject telemetry into downlink chain
• Telecommand processing
• Receive telecommand from the uplink chain
• Proces telecommands
• Customised for specific spacecrafts

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PSS Environment
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PSS Main Functions

• Real-time processing of telemetry and telecommand
• Playback of telemetry frames
• Fixed frame generation
• Baseband processing
• Digital IF and sub-carrier based modulation
  demodulation
• Uplink tracing
• Several monitoring and control interfaces

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Real-time Telemetry Generation

• CCSDS packet telemetry
• Generation of CCSDS source packets, IP packets
• Insertion of packets into frames
• Multiplexing of VC frames on the downlink
• Insertion of idle frames and packets
• Automatic generation of time reporting packets
• ESA PCM telemetry

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Real-time Telecommand Reception

• CCSDS Telecommand
• Telecommand format checking
• FARM processing
• Updating CLCW variables
• Generation of verification report packets (ECSS
  PUS)
• ESA PCM Telecommand
• 3 formats supported (ESA 96 bits, ENVISAT 96
  bits, transparent)
• Telecommand format checking

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Playback of Telemetry Frames

• Several playback configurations
• File format (header, trailer) configurable
• Start playback at frame offset
• Endless playback
• Suspend/resume playback
• External telemetry API

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TM/TC Relay
Control Centre
Ground Station
RCF SLE Service
Operational Simulator
CLTU SLE Service
RAF/RCF SLE Service
Mission Control System
CLTU SLE Service
IF Station Equipment
TM/TC Baseband Equipment
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TM/TC Relay

• Relay telemetry frames received from the
  operational simulator
• Update frame sequence counter
• Update checksum
• Generate idle frames when needed
• Store last received CLCW

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Uplink Tracing
Ground Station
IF Station Equipment
TM/TC Baseband Equipment
MCS
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Uplink Tracing

• Uplink Monitoring
• Log in real-time the uplink status during
  operations
• bit rate
• frequency
• lock status
• Telecommand Tracing
• Log in real-time the telecommands uplinked to the
  satellite
• Information stored in uplink-tracing trace file

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Bit Error Rate Measurements

• Run on any telemetry flow
• Compare output of sending chain with input
  received from downlink chain
• Calculate and log results
• Number of symbols compared
• Number of symbol errors
• Symbol error rate

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Logging

• System Log
• Provide history over several months
• Record PSS start/stop, fatal errors, system
  shutdown, start/stop of main functions
• Engineering Log
• Log activities during operations
• Log telemetry and telecommand frames and packets,
  FARM processing, verification reports
• Based on a circular buffer
• Log message include generation time, log
  originator, log type
• Filtering possible on log type, log level

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Baseband, Modulation Demodulation

• Baseband processing
• Frame completion
• Error detection/correction
• Randomisation
• Differential encoding
• Decoding of telecommand data
• Digital Intermediate Frequency (IF) modulation
  and demodulation
• Sub-carrier modulation and demodulation

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Monitoring Control

• Two man machine interfaces
• PSS dedicated MMI
• Several display windows
• Real-time display of PSS statuses, log messages
• Commanding facilities
• Generic configurable window
• Scripting facilities
• Generic MMI used for specific tests
• Support monitoring control by Ground Station
  Manager (GSM)
• Remote maintenance interface

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PSS Mark III MMI
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Generic MMI (SIMSAT)
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Remote Maintenance Interface

• Remote Monitoring Control of PSS functions
• File transfer (including software installation)
• Configuration and installation checking

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PSS Customization

• Generic PSS can be customized by
• Configuration
• Providing telemetry or telecommand files
• Implementing specific processing in the
  Spacecraft Specific Model Extension (SSME)

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Configuration
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Configuration

• Configuration stored in a database
• Complete content of the telemetry flow (frame and
  packet format and header content, VCs,
  application process, source packets, VC
  multilpexing scheme)
• Telecommand flow (frame and packet formats, VCs,
  application processes, verification reports)
• Baseband, modulation and demodulation parameters
• One database per spacecraft
• Interactive GUI based configuration tool
• Consistency and correctness checking

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Spacecraft Specific Model Extension

• Extensibility API
• Provide access to PSS commands and data
• Provide means to pass telemetry frames and
  packets or telecommands to the SSME for further
  processing
• SSME
• Interface to the PSS via the extensibility API
• Implements specific spacecraft processing
• Specific telecommand processing
• Management of telemetry parameters
• Special PCM telecommand decoding
• SSME Framework

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Architecture

• Highly modular system
• One hardware module (IMBU)
• Several configurable software modules
• TM/TC Spacecraft Model (TTSCM)
• PSS Application Software
• PSS MMI
• PSS Monitoring and Control Interface
• Spacecraft Specific Model Extension (SSME)
• SIMSAT Run-time environment

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System Partitioning
PSS Workstation
PSS MMI
Engineering Log
IMBU
Script Engine
IF 70 MHz
IF 230 MHz
SIMSAT Kernel
SIMSAT MMI
Sub-carrier TM
Sub-carrier TC
SSME
MC I/F
Baseband TM
PSS Application Software
Ground Station Manager
Baseband TC
TTSCM
BER I/O
PSS DB
External Clock
System Log
CFG Tool
Signal Monitoring
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Integrated IF Modem and Baseband Unit (IMBU)
TM Module
TM Chain
TM Data Processing and Fixed Frame
Generation (including Coding, etc)
Modulation and Baseband Output Routing
LAN Interface
LAN
Bit Error Rate Functional Block
BER Control (Initialisation, Checking, Reporting)
BER Reception and Comparison
TC Module
TC Chain
LAN Interface
TC Acquisition and Error Detection/Correction
Demodulation and Baseband Input Routing
LAN
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Integrated IF Modem and Baseband Unit (IMBU)

• Highly portable and compact unit
• Digital processing
• Configurable on-the-fly
• No hard-coded restrictions
• Independant TM TC modules

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TM/TC Spacecraft Model (TTSCM)

• Core of the PSS software
• Fully configurable via the configuration
• Generate the telemetry flow from the source
  packets to the frames sent on the downlink
• Process the telecommands
• Can be used as part of the PSS or as an
  independant module
• Interface to the SSME via the extensibility API

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Ground Segment Subsystems Tests
Ground Station
IF and Sub-Carrier
Baseband TM/TC
IF Station Equipment
TM/TC Baseband Equipment
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Data Flow and Command Tests
Ground Station
Control Centre
LAN/WAN
IF and Sub-Carrier
Baseband TM/TC
Mission Control System
TM/TC Baseband Equipment
IF Station Equipment
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MCS Test and Validation
Control Centre
TTSCM SSME
Mission Control System
Ground Equipment Simulation