Req. 5.3.11: "GRB Response"
The LAT FSW shall respond to GRB alert messages from all sources (a Rapid Burst Alert from a source external to GLAST, a GRB alert message/interrupt from the GBM, or an internally generated GRB alert) when in Sky Survey or Pointed Observation modes.
Basis (help)
[1] (3.1.2.4, 3.3.2.4.1-2), [2] (3.2.6.5.1-2)
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1: "Mission System Spec." (NASA 433-SPEC-0001)
3.1.2.4: "Transient Event Response"
The GLAST system shall respond to gamma-ray bursts and other transient events that are detected on board.
3.1.2.4.1: "Alert Transmission"
The GLAST system shall automatically transmit an alert message of a transient event to the appropriate ground networks.
3.1.2.4.2: "Repointing"
The GLAST system shall be capable of repointing the observatory to observe qualified gamma-ray bursts.
3.3.2.4.1: "Autonomous Repointing"
The observatory shall be capable of repointing autonomously from either sky survey mode or pointed observation mode in response to GRBs detected on board.
3.3.2.4.1.1: "Go/No-Go Decision Making"
The observatory shall be capable of go/no-go decision making in response to on-board repointing commands.
3.3.2.4.1.2: "Automatic Resume"
Upon completion of a repointed observation that is performed autonomously, the observatory shall automatically resume the previously interrupted observation (sky survey or pointed observations).
3.3.2.4.2: "Targets of Opportunity"
The observatory shall accept repointing commands from the ground to acquire Targets of Opportunity.
3.2.6.5.1: "LAT-detected Transient Event Data Reporting"
3.2.6.5.1.1: "LAT generated Burst Alert Telemetry"
For each detected burst, the LAT shall send alert telemetry to the SC on the 1553 bus for immediate transmission to the ground.
3.2.6.5.1.2: "Autonomous Repoint Request Telecommand"
When a detected burst meets a LAT determined criteria, the LAT shall issue an Autonomous Repoint Request (ARR) telecommand to the SC.
3.2.6.5.1.3: "Autonomous Repoint Request Response"
The SC shall always inform the LAT as to whether or not the SC did accept and process the repointing request.
3.2.6.5.1.4: "Telecommands to the GBM"
For each detected burst, the LAT shall send telecommands to the GBM as defined in the LAT-GBM ICD.
3.2.6.5.2: "GBM-detected Transient Event Data Reporting"
For GBM detected Transient Events, the LAT receives the following information.
3.2.6.5.2.1: "Immediate Trigger Signal"
The LAT receives a single pulse from the GBM for each burst detected by the GBM as described in section 3.2.7.
3.2.6.5.2.2: "GBM Telecommands to LAT"
For each burst event detected by the GBM, the LAT shall receive, a series of telecommands across the 1553 bus as defined in the LAT-GBM ICD.
Context (help)
