on-orbit performance of the glast burst...

BackgroundProjectsResults

On-Orbit Performance of theGLAST Burst Monitor

Curran D. Muhlberger (RA) Charles A. Meegan (PI)

Cornell University

University of Maryland

August 8, 2008

Curran D. Muhlberger, Charles A. Meegan On-Orbit Performance of the GLAST Burst Monitor


What is GLAST?What is GBM?What is it Good for?

Outline

1 BackgroundWhat is GLAST?What is GBM?What is it Good for?

2 Projects

3 Results




What is GLAST?

Gamma-Ray Large Area SpaceTelescopeSuccessor to Compton GammaRay ObservatoryLaunched Wednesday, June 11,2008Two instruments:

Large Area Telescope (LAT)GLAST Burst Monitor (GBM)




What is GBM?

The GLAST Burst Monitor supportsthe LAT by detecting and localizinggamma-ray bursts.

Digital successor to BATSE12 NaI detectors2 BGO detectors (overlap LATenergy range)Extremely large field-of-viewRapid burst notification for robotictelescopes




What is it Good for?

Gamma-ray burstsare the mostpowerful events inthe UniverseMost gamma-raysources are stillunidentifiedHigh energyastronomy canprobe fundamentalphysics



Collaboration SupportPerformance EvaluationOperations Support

Outline

1 Background

2 ProjectsCollaboration SupportPerformance EvaluationOperations Support

3 Results




GIOC Display Panel

Real-time display wall powered by STK




InterPlanetary Network

Software Features

Generate high-reslightcurve from TTE dataChoose detectors tomaximize signal-to-noiseCorrectly adjust for leapseconds and deadtimeFormat output for use byexisting software

Cou

nt R

ate

[cps

]

Comparison of GRB Lightcurves

IPN

1000 1500 2000 2500 3000

Cou

nt R

ate

[cps

] CTIME

1000 1500 2000 2500 3000

Cou

nt R

ate

[cps

]

Time from Trigger [s]

CSPEC

1000 1500 2000 2500 3000

-4 -2 0 2 4 6 8 10 12

The InterPlanetary Networkuses observations from multiplespacecraft to pinpoint a burst’slocation.




Performance Evaluation Software

Software Products

Portable C library forprocessing Level 1 dataConsistency check forCSPEC, CTIME, and TTEBurst hardness calculator

Parser for Automatic GainControl diagnostic packetsCoincidence rate calculatorBug discovery anddiagnosis

Energy [keV] Timescale [ms] zmax Rate [yr−1]

50-300 64 4.5 23.550-300 128 4.5 11.810-50 64 5.5 0.310-50 128 5.5 0.0≥ 100 64 5.5 0.3≥ 100 128 5.5 0.1




Operations Support

Operations Support Software

IOTL parser and report generatorIOTL/ATS comparison parserOnline database viewers

Level 0 files by dateLevel 1 continuous filesLevel 1 trigger files




Web Applications



Current StatusThe End

Outline

1 Background

2 Projects

3 ResultsCurrent StatusThe End




Results

GIOC features functional andstylish real-time display

CSPEC, CTIME, and TTE dataappear to be self-consistent

Timing bugs discovered anddiagnosed

Trigger algorithm thresholdsreset knowing expectedcoincidence rates

IPN to receive custom-formattedhigh-resolution lightcurves

Scientists can quickly calculateburst hardness ratios

GBM team members have webaccess to pipeline databases

Operators can quickly checkIOTLs for correctness

Future programs can build off ofa high-level C library

Everyone learned somethingnew!




Questions?


on-orbit performance of the glast burst...

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