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FSW Requirement 5.3.11.6 (prev, next)

Req. 5.3.11.6: "GRB Alert Message Latency"

For a GRB meeting the conditions defined in 5.3.10.2.1, the SIU FSW shall send a GRB alert message to the SC within 5 seconds of detection, for immediate relay to the ground. The goal is to provide the notification within 2 seconds.

Basis (help)

[1] (3.1.2.4.1), [3] (5.2.15), [4] (5.4.7)

    1: "Mission System Spec." (NASA 433-SPEC-0001)

      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: "LAT Performance Spec. - Level II(b) Spec." (LAT-SS-00010)

      5.2.15: "GRB Notification Time to Spacecraft {SRD Table 2}"

      The GRB notification time to spacecraft shall be less than 5 seconds after the detection of a GRB, for bursts with the characteristics given in 5.2.14. The goal is to achieve GRB notification time of less than 2 seconds after the detection of a GRB, for bursts with characteristics given in 5.2.14.

    4: "LAT T&DF Subsystem Spec. - Level III Spec." (LAT-SS-00019)

      5.4.7: "Filter Identified Transients"

      The event filtering shall provide near real-time detection of transients.

Context (help)

Test(s)

    012b: Additional Science Processing - Repointing Logic

    This test verifies the LAT's internal logic for requesting repointing for LAT-detected GRBs. Verification shall include a variety of scenarios, including repointing enable, different operational modes, and conflicting requests. The test shall verify that the SIU FSW responds to these events properly, forwarding repointing requests to the SC, sending a command indicating the time of GRB detection, and (for a LAT-detected burst alert) issuing a LAT closeout message to the GBM.