GLAST LAT Project
Gamma-ray Large
Area Space
Telescope
ISOC Peer Review - March 2, 2004
GLAST Large Area Telescope
ISOC Peer Review
2.1 Requirements
Lori Bator
ISOC Chief Engineer
Document: LAT-PR-03213-01
Section 2.1 Requirements
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
State of ISOC Requirements
• ISOC requirements given here are detailed in LAT-SS-00015,
“LAT ISOC Performance Specification - Level II (B)
Specification”
– Currently being updated from 8/31/00 released version but
changes are more a reorganization of the material and
reassignment of more detailed requirements to the Level III
specification documents
– Requirements map to Ground System Requirements
Documents (GSRD)
– Requirements also address, on a high level, elements in the
Operations Data Products ICD and Science Data Products
ICD
Document: LAT-PR-03213-01
Section 2.1 Requirements
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
State of ISOC Requirements, cont’d
• Requirements are divided into major categories
– Science Operations → SOG
– Instrument Operations → LOF
– Science Analysis and Data Processing → SOG/SAS
– Interfaces → SOG/LOF
– General → all
• Due to the recent formulation of the SOG concept, science
operations Level II requirements are fairly general at this point
– Level III SOG requirements are currently in draft
• Level II LOF requirements are fairly robust due to interactions
with the ground systems team through GOWGs and TIMs
Document: LAT-PR-03213-01
Section 2.1 Requirements
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
Documentation Flow
Mission System
Specification
433-SPEC-0001
Operations Data
Products (ICD)
Interface
Rqmts
Science
Rqmts
LAT-SC Interface
Requirements
Document
433-IRD-0001
Mission
Rqmts
Science Data
Products (ICD)
Ground System
Requirement
Documents
433-RQMT-0006
Mission
Science
Requirements
Document
433-SRD-0001
TCS Performance
Specification
LAT-SS-00715
LAT ISOC
Performance
Specification
LAT-SS-00015
LAT-SC Interface
Control
Documents
Trigger & Dataflow
Subsystem
Specification
LAT-SS-00019
TKR Subsystem
Specification
LAT-SS-00017
ACD Subsystem
Specification
LAT-SS-00016
Radiator Design
Specification
LAT-SS-00394
X-LAT Plate
Design
Specification
LAT-SS-01240
Grid Box Design
Specification
LAT-SS-00775
Document: LAT-PR-03213-01
Power
Subsystem
Specification
LAT-SS-00136
SAS
Subsystem
Specification
LAT-SS-00020
CAL Subsystem
Specification
LAT-SS-00018
LAT Flight SW
Specification
LAT-SS-00399
ACD Design
Specification
LAT-SS-00352
LAT TKR Design
Specification
LAT-SS-00134
LAT Trigger
Specification
LAT-SS-00284
LAT Dataflow
Specification
LAT-SS-00285
LAT Readout
Electronic
Specification
LAT-SS-00152
Tower Power
Supplies
Specification
LAT-SS-01537
LOF
Subsystem
Specification
LAT-SS-00021
SOG Subsystem
Specification
LAT-SS-XXXX
SAS Design
Specification
LAT-SS-00505
LAT Operations
Facility
Specification
LAT-SS-01783
CAL Design
Specification
LAT-SS-00210
Section 2.1 Requirements
LAT Subsystem
Mechanical
Subsystem
Specification
LAT-SS-00115
LAT
Environmental
Specification
LAT-SS-00778
Design Specification
LAT Performance
Specification
LAT-SS-00010
LAT
Interface
Rqmts
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
Level III Requirements Documents
Document
Number
Title
Release
Date
Comments
LAT-SS-00020
Science Analysis Software Level III Specification
1/7/2002
Will update if
necessary
LAT-SS-00021
LAT Operations Facility
Subsystem Specification Level III Specification
1/7/2002
Update is in
review
LAT-SS-000XX
Science Operations Group Level III Specification
Document: LAT-PR-03213-01
Not released
In draft
Section 2.1 Requirements
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
Science Operations Requirements
Requirement
GSRD Reference
Produce, monitor and update calibration constants for the instrument and
generate Instrument Response Functions (IRFs) needed for science analysis
LIOC2030
Assess the LAT instrument performance and compare actual performance
against predicted performance
LIOC6100
Optimize the performance of the LAT instrument
Archive data on the performance of the LAT instrument
Document: LAT-PR-03213-01
LIOC6130
Section 2.1 Requirements
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
Instrument Operations Requirements
Requirement
GSRD Reference
Monitor the health and safety of the instrument
LIOC5000
LIOC6100
Process and analyze LAT housekeeping data
LIOC2090
LIOC6120
Define the operating limits for the LAT instrument and shall monitor for and
respond to anomalous configurations or states
LIOC2090
LIOC5020
Maintain records of the operation and health of the LAT instrument
LIOC4010
LIOC6110
LIOC6130
Maintain the status of on-board operating parameters and control the
configuration of the LAT instrument
LIOC4230
LIOC6150
Generate LAT instrument commands and identify procedures to direct the
safe upload of the commands
LIOC4100
Develop and maintain validated command and telemetry databases used for
generating LAT instrument commands and analyzing the health, performance,
and operation of the LAT instrument
LIOC2100
Document: LAT-PR-03213-01
Section 2.1 Requirements
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
Instrument Operations Requirements, cont’d
Requirement
GSRD Reference
Maintain, update, and validate the operation and performance of the LAT
onboard instrument flight software
LIOC4200
LIOC4230
Maintain an instrument simulator for validating and verifying changes to flight
software and command procedures, and also for use in anomaly resolution
LIOC4210
LIOC4220
Provide mission operation support for the LAT instrument
• Provide instrument command uploads to the GSSC for on-orbit instrument
operations and to the MOC during pre-launch test and early orbit periods
• Coordinate LAT commanding schedules with the GSSC
• Coordinate the resolution of LAT instrument anomalies with the MOC
• Perform initial tests and analysis of LAT instrument operation and
performance during an on-orbit checkout period of 60 days
• Support an on-orbit operational lifetime of a minimum of 5 years following
an initial period of on-orbit checkout
LIOC3000
LIOC4000
LIOC4020
LIOC4030
LIOC4040
Document: LAT-PR-03213-01
Section 2.1 Requirements
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
Science Analysis and Data Processing
Requirements
Requirement
GSRD Reference
Receive Level 0 data from the MOC and shall process the data into Level 1
event data and instrument diagnostic data within 24 hours of receipt from
the MOC
• Evaluate the quality of the Level 0 data and determine if retransmission of
the data from the MOC is required
• Process retransmitted Level 0 data within 24 hours of receipt from the
MOC
• Process Level 0 data received from the MOC that duplicates or overlaps
portions of previously received Level 0 data
LIOC1520
LIOC2000
LIOC2050
LIOC2055
LIOC2070
LIOC6020
Autonomously receive real-time housekeeping data in near real time from the
MOC and shall process the data for diagnostic use
LIOC5010
LIOC7010
Process unfiltered data generated by the instrument hardware trigger
LIOC2075
Maintain a Level 1 processing pipeline for event reconstruction and
classification
LIOC2040
Develop algorithms to interpret the subsystem response, apply calibration
constants, and to find and identify incident photons
LIOC6015
Develop and maintain software to simulate the detailed response of the LAT
to charged particles and gamma rays
Document: LAT-PR-03213-01
Section 2.1 Requirements
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
Science Analysis and Data Processing
Requirements, cont’d
Requirement
GSRD Reference
Maintain a processing pipeline for Level 2 analysis tasks that can be
automated, such as searching for transient sources, monitoring the in-flight
IRFs, and refining information about alerts for transient sources generated by
the instrument
LIOC2010
Develop and provide to the GSSC and LAT team science analysis tools to
analyze Level 1 data
LIOC2020
Provide Level 1 and Level 2 data to GSSC and the LAT team in an agreed
upon format
LIOC2010
LIOC2060
Provide data to any associated international or domestic mirror sites provided
as part of the LAT team efforts
Archive all raw data and processed data products for the duration of the
mission.
LIOC2080
LIOC6130
Archive LAT test and calibration data obtained during pre-launch testing
LIOC6140
Receive and process LAT transient alert messages from the MOC
• Use LAT science data to validate and refine the transient alert information
• Transmit refined transient alerts to the Gamma Ray Burst Coordinates
Network (GCN)
• Receive, process, and respond to LAT instrument alert messages
LIOC2085
LIOC2086
Document: LAT-PR-03213-01
Section 2.1 Requirements
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
Interface Requirements
Requirement
GSRD Reference
Interface with the GSSC, LAT team, and LAT mirror sites to provide and
receive science data products
LIOC2020
LIOC2060
Interface with the GSSC to provide and receive operational data products,
including instrument commands
LIOC1500
LIOC4020
LIOC4030
LIOC4040
LIOC4110
Interface with the MOC to provide and receive operational data products
LIOC1510
LIOC2110
LIOC2120
LIOC4050
LIOC4130
LIOC6000
LIOC6010
Document: LAT-PR-03213-01
Section 2.1 Requirements
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
General Requirements
Requirement
GSRD Reference
Adhere to mission specified data standards and formats
LIOC0010
Maintain the LAT ISOC for the entire mission lifetime with no loss in ISOC
capability or performance
LIOC0020
LIOC1000
Accept autonomous data transfers from the MOC
LIOC7000
Connect to the other operations and support centers by an intranet of wide
area networks that is closed to, or protected from, public users of the external
internet
Document: LAT-PR-03213-01
Section 2.1 Requirements
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GLAST LAT Project
ISOC Peer Review - March 2, 2004
Conclusion
• Solid Level II requirements are in place and track to GSRD
• Level III requirements for SAS and LOF are in place
• SOG Level III requirements are continuing to be identified and
developed
Document: LAT-PR-03213-01
Section 2.1 Requirements
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