ESA Submission to Space DTF RFP1: Telemetric and Command Data Specification

1
ESA Submission to Space DTFRFP-1 Telemetric
and Command Data Specification
OMG Technical Meeting Anaheim 2002

• Mario Merri and Roger Thompson
• ESOC
• Robert Bosch Strasse 5
• 64293 Darmstadt
• Germany
• 49 6151 902292
• mario.merri_at_esa.int

2
Introduction

• ESA Submission to OMG Space DTFRFP-1 Telemetric
  and Command Data Specification
• Objectives
• Existing TM/TC Standards
• SCOS-2000
• Summary of Proposed Specification
• Overview of SCOS-2000 MIB
• RFP Compliance
• Discussion Items
• Example MIB Table XML Schema

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Objectives

• Standardised Information Model for Telemetry and
  Command Data Definitions
• Allow exchange of TM/TC Definitions
• Between Mission Phases
• Between Organisations
• Between Systems
• without need for re-implementation or
  re-validation
• Broad Scope within Space Data Systems
• All Phases of Mission Lifecycle
• All Segments of Mission Infrastructure
  (Spacecraft, Payload Ground)
• Limited to Definition and not Transfer of TM/TC
  data
• As Inclusive as Possible
• Support Legacy Missions
• Support Existing Standards
• Extensible Mission Specific and Future Standards

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TM/TC Data Exchange
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Existing TM/TC Standards

• Frame-based Legacy Systems
• CCSDS Packet TM/TC
• Concept of Packets
• Greater flexibility than fixed format Frames
• International Standard
• Widespread Use
• ECSS Packet Utilisation Standard, ECSS-E-70-41,
  (PUS)
• Concept of end-to-end Services
• European Standard
• Based on CCSDS Packet TM/TC
• Standardised packet usage
• Used or planned for ESA and Non-ESA
  MissionsXMM, MSG, INTEGRAL, GOMOS, ATV, Ørsted,
  PROBA, ROSETTA, MARS EXPRESS, FIRST/PLANK,
  CRYOSAT, GOCE, GALILEO
• PUS Compliance gives Greatest Inclusivity (all of
  above)
• PUS Compatibility Essential for use of TM/TC Data
  Specification by ESA

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Existing TM/TC Standards
Frames
Space
Ground
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SCOS-2000

• ESA Satellite Control System Kernel
• Mission Control and Satellite Check-out
• Supports Packet TM/TC and PUS
• Object-oriented Design
• C/UNIX (Solaris and Linux)
• External Data Access interfaces based on CORBA
• Open Source
• Established Current/Future Mission Base
• ESA MissionsHuygens MTP LEOP Proba MSG LEOP
  Integral Rosetta Mars Express SMART-1
  Cryosat GOCE
• Other AgenciesDLR, CSA and EUTELSAT
• Award Winner at OMG Object World Conference,
  Berlin 1999

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Proposed Specification

• Utilises Information Model inherent in SCOS-2000
  Mission Information Base (MIB)
• compliance with CCSDS Packet TM/TC
• compliance with ECSS PUS
• compatibility with legacy Frame-based TM/TC
• Representation based on XML Schema (W3C
  recommendation)
• XML representation of SCOS-2000 MIB (was already
  in progress)
• Straightforward mapping to Relational DB
  Structure
• Limited Enhancements for compliance with
  Mandatory Requirements
• Data Representations based on ECSS PUS
• On Adoption, ESA will develop
• SCOS-2000 Extension for Import/Export of SCOS MIB
  in specified XML Format

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SCOS-2000 MIB Monitoring Tables

• Packets
• PID Packet Identification File
• PLF Parameter Location File fixed format
  packets
• VPD Variable Packet Definition File variable
  length packets
• Parameters
• PCF Parameter Characteristics File
• CAF Calibration Curve File
• CAP Calibration Curve Definition File
• MCF Polynomial Calibration Curve Definition File
• TXF Text Strings Calibration File
• TXP Text Strings Calibration Definition File
• OCF Out-of-Limits Checks File
• OCP Out-of-Limits Definition File

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Relationships Monitoring Schemas
CAF_NUMBR
CAF_NUMBR
CAF
CAP
CAP_NUMBR
PCF_RELATED
PCF_VALID
BASED ON PCF_CATEG
PCF_NAME
TXF_NUMBR
PCF_CURTX
TXF
TXP
TXP_NUMBR
PCF
TXF_NUMBR
PCF_NAME
PCF_NAME
PCF_NAME
VPD_NAME
PLF_NAME
OCF_NAME
OCP
OCF
OCP_NAME
OCF_NAME
PLF
VPD
PLF_SPID
VPD_TPSD
PID_SPID
PID_TPSD
PID
Scope of XML Schema
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SCOS-2000 MIB Commanding Tables

• Packets
• TCP TC Packet Header File
• PCDF Packet Headers Definition File
• Commands
• CCF Command Characteristics File
• CDF Command Details File
• PTV Command Pre-Transmission Validation File
• CVP Command Verification Profiles File
• CVS Command Verification Stages File
• CVE Command Verification Expression File
• Parameters (Command Arguments/Fields)
• CPC Command Parameter Characteristics File
• CCA Parameter Calibration Curve File
• CCS Calibration Curve Set File
• PAF Parameter Alias File (Text De-Calibration)
• PAS Parameter Alias Set File
• PRF Parameter Range File
• PRV Parameter Range Value File
• PCPC Packet Header Parameter Characteristics File

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Relationships Command Schemas
PCDF_TCNAME
PCPC_PNAME
TCP_ID
PCPC
TCP
PCDF
TCP_ID
PCDF_PNAME
CCF_PKTID
CPC_PNAME
CDF_CNAME
PTV
PTV_CNAME
CDF
CCF
CPC
CCF_CNAME
CCF_CNAME
CDF_PNAME
CCF_CNAME
CVS_ID
CVE_CVSID
CVS
CVP
CVE
CVS_ID
CVP_CVSID
CVP_TASK
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Relationships Command Param Schemas
CDF
CDF_CNAME
CPC_CNAME
CCA
CPC
CCA_NUMBR
CCA_NUMBR
CCS
CPC_CCAREF
CCS_NUMBR
PAF
PAF_NUMBR
PAF_NUMBR
PAS
PAS_NUMBR
CPC_PAFREF
PRF
PRF_NUMBR
PRV
PRF_NUMBR
CPC_PRFREF
PRV_NUMBR
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SCOS Operations Language

• Commanding Tables reference TM Parameter Values
• SCOS OL Provides a means to define Synthetic
  Parameters
• Used for Derived Parameters
• Used to Define Conditions for
• Parameter Validity
• OOL Check Validity
• Command Pre-Transmission Validation
• Command Verification Stages
• SCOS OL Defined Externally to SCOS MIB
• For TM/TC Data Specification, may be considered
  an additional Field or sub-table of the PCF
  included in revised proposal
• Algorithm Type (e.g. SCOS OL)
• Algorithm Input List (referenced Parameters -
  allows consistency checking)
• Algorithm Defined Externally (referenced by Param
  Name)

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SCOS Command Sequences

• SCOS MIB also supports concept of Command
  Sequences
• Have ID and Parameter like Commands
• Expand into Sequence of Commands
• Not included in TM/TC Data Specification could
  be added

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Proposed Data Representations

• Supported Data Representations
• PUS Recommendation
• Use Parameter Type Code (PTC) and Parameter
  Format Code (PFC)
• Extensible
• Includes
• Boolean
• Enumerated
• Unsigned and Signed Integers
• Simple and Double Precision Reals
• Bit, Byte and ASCII Strings
• Absolute and Relative Times
• Common Schema
• Common, TM and TC Field Types
• Extensible
• Included in Table Schema

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RFP Mandatory Requirements

• High degree of Compliance
• Partial or Non-compliances noted
• Data Categorisation not fully supported
• Authorisation limited to identification of
  Hazardous Commands
• Object References supported indirectly
• Does not address TM Framing
• Does not address Stream Definition
• Does not address Encryption, Block Encoding or
  Randomisation
• Several non-compliances relate to Packaging
  InformationWhile important it is noted that
  these are usually either
• Static (do not change within context of a given
  mission)
• Dynamic (selected by operators/automation tools
  at run-time)

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RFP Optional Requirements

• Security and Access Policies
• not covered
• Data and Command Definition for Ground System
  and/or On-board Instrument Data Definition
• where these are compatible with PUS, then this
  can be accommodated within the proposed standard

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RFP Discussion Issues

• applicability of the proposed approach to
  real-time design, testing and operation of a
  satellite
• Proven applicability to Spacecraft Operations
• Proven applicability to Satellite Check-out
• The specifications could be used in the following
  contexts
• During design of Mission Specific PUS
  Implementation
• Coordination of TM/TC Definitions between
  Subsystems
• Transfer between test/checkout and operational
  systems
• Transfer between primary and backup control
  systems
• Transfer between nominal and special (e.g. LEOP)
  control systems
• Supplied with TM/TC History, for support by
  analysis tools
• Support to external systems using Live TM/TC Data
  Access

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Example Table (PLF)
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Example Schema (PLF) 1
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Example Schema (PLF) 2
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Schema Revisions in Issue 1.1

• SCOS Tables combined to reduce number of Schema
• Monitoring Schemas
• Parameters
• Calibration Data
• Parameter Checks
• Packets
• Commanding Schemas
• Packets
• Packet Parameters
• Commands
• Command Checks
• Calibration Data
• Algorithm Definitions SCOS OL Added to
  Parameter Schema

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Further Potential Enhancements

• Overlay System Hierarchy Device/Domain
• Mission
• Domain
• Sub-Domain / Device APID?
• Separate PUS Data as Distinct Schema/Table
• Incorporate Command Sequences

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PUS Schema as part of Packet Schema