GBM Simulation and Instrument Response R Marc Kippen

GBM Simulation and Instrument Response R. Marc Kippen Space and Atmospheric Sciences Group Los Alamos National Laboratory Simulations and Response / R. M. Kippen (LANL) -1 - GBM BWG Review, 31 August 2004

GBM Detector / Instrument Response GRB Photon Spectrum Instrument Response Instrument Background Observed Data GR B Simulations and Response / R. M. Kippen (LANL) -2 - GBM BWG Review, 31 August 2004

Simulation and Detector Response Software ª Definition: Multi-purpose software suite that computes the physical and instrumental response of the GBM instrument system l l Primary purpose: generate detector response functions critical to the analysis of flight science data Other uses: instrument design; interpretation of calibrations; design of flight and ground analysis algorithms & s/w ª Technique: Numerical simulation — Monte Carlo radiation transport l Verified through, and incorporating results from experimental calibration Major Components ª ª ª Simulations and Response / R. M. Kippen (LANL) -3 - Mass model (geometry + composition) Incident particle distributions Radiation transport physics Instrumental/calibration effects DRM database DRM synthesizer/generator GBM BWG Review, 31 August 2004

Key Functional Specifications GBM SIM/DRM S/W Functional Specs GBM-SPEC-1025 (reviewed at GSW PDR) GBM IODA S/W Functional Specs GBM-SPEC-1031 (reviewed at GSW PDR) ª Complete and accurate interaction physics (included in core simulation package — GEANT 4) ª Accurate mass models, environment models, and instrument models (but not overly complex) ª Later stages of development require S/C models (including LAT model) Simulations and Response / R. M. Kippen (LANL) ª Verification through comparison with experimental data ª Final DRMs must include contribution from atmospheric scattering (+direct detector and S/C scattered response) ª GLAST S/C will have rapid slew capability — different DRMs are required whenever aspect changes by > 1° ª DRM generation s/w is part of GBM IODA s/w and subject to the same requirements for standards, configuration control, etc. -4 - GBM BWG Review, 31 August 2004

Development Organization GBM Project Manager (Elrod) Ground System Manager (Paciesas) Ground Software Lead (Preece) Ground Software Review Board GSW Config. Mgr. (Connaughton) ª SIM/DRM software designed and developed at LANL in collaboration with GBM PI and GSW lead GBM Principal Investigator (Meegan) Ground Software Development Team Simulations and Response / R. M. Kippen (LANL) SIM & DRM System Lead (Kippen) Developers (Hoover) Ground Software Test Team (Diehl, lead) -5 - ª Development process falls under GSW Development Plan (GBM-PLAN-1023) ª Final products (s/w and data) delivered to GBM PI at NSSTC (also available to MPE and other interested parties) GBM BWG Review, 31 August 2004

Phased Software/Model Development Environment Models Instrumental Effects Prototype Detectors Prototype Environment Prototype Thresholds, Resolution Flight Detectors, Det. Level Config. Test Environment 1 Detector Level Env. Test Environment 1 Det. Cal. Results Flight Detectors, Sys. Level Config Test Environment 2 System Level Env. Test Environment 2 Sys. Cal. Results Calibration Phase Design Phase Mass Models Flight Detectors, SC Level Config. with Spacecraft/LAT in Test Configuration ª Software and models require cross-validation with calibration data ª Three phases of SIM/DRM sw/model development l ª l Test Environment 3 Spacecraft Test Facility and Source Holder Design Calibration ª Test Environment 3 S/C Cal. Results Simulate prototype detectors Simulate three levels of calibration/test l Operations Phase l Flight Detectors, Flight Configuration with Spacecraft/LAT in Flight Configuration Flight Environment with Atmospheric Scattering Model Flight Performance with Periodic Updates from In-flight Calibration Database l l Operation ª ª Simulations and Response / R. M. Kippen (LANL) -6 - Detector level GBM system level On-spacecraft level In-flight configuration appropriate for analysis of science data DRM generation GBM BWG Review, 31 August 2004

Implementation: GBM REsponse Simulation System GRESS gbmsim GBM instrument physical simulator calsim Instrumental/calibration effects & data packager atmosim Atmospheric scattering simulator arpack Atmospheric scattering data packager drmgen Application-specific DRM generator Simulations and Response / R. M. Kippen (LANL) ª Integrated package that will encompass all GBM instrument response software and data needs ª Configuration controlled as a single deliverable package with component software/data modules ª All packages (and their dependencies) use GNU compilers — mainly g++ ª All data files have headers with detailed version & job tracking data ª Final phase package will be a subset of the GBM IODA software, cf. GBMSPEC-1036 (GSW Arch. Design) -7 - GBM BWG Review, 31 August 2004

Implementation: GBM REsponse Simulation System GRESS/IODA Overlap Area GRESS Mass model Cmds. gbmsim Cmds. root files Cal. Params. calsim Spectrum or DRM Data Analysis Software (IOC) drmdb caldb drmgen Aux. data IODA Application Specific DRM atmosim Cmds. Mass model root files arpack armdb Source Location Software (SSC & IOC) Spectrum or ARM Note: a separate, reduced DRM/ARM database is used for BAP software (based on same simulation data) Simulations and Response / R. M. Kippen (LANL) -8 - GBM BWG Review, 31 August 2004

How – Direct Instrument Response gbmsim — Raw “physical” data Simulations and Response / R. M. Kippen (LANL) calsim — Packaged, instrument-like data -9 - GBM BWG Review, 31 August 2004

How – Atmospheric Scattered Response atmosim — Raw “physical” data arpack — Packaged data matrix collection surface NRLMSISE-2000 atmospheric model used to create concentric shell mass model Simulations and Response / R. M. Kippen (LANL) - 10 - GBM BWG Review, 31 August 2004

How — Putting it all Together drmdb — direct response db armdb – Atmos. Resp. db drmgen — burst-specific response generator Data Analysis – spectral fitting and localization Simulations and Response / R. M. Kippen (LANL) - 11 - GBM BWG Review, 31 August 2004

How — Response used for Spectral Analysis rmfit/xspec — spectral model “hypothesis testing” Model GRB Spectrum Total Det. Response Background Model Observed/Predicted Counts ª Empirical, timedependent model based on data before and after burst ª Observed and predicted counts compared via test statistic ª Chi-squared (Gaussian) or Poisson log Likelihood ª Optimize test Stat. iteratively iterate ª Parameterized spectral models ª Built-in models or “custom” models ª From drmgen ª Updated automatically when S/C pointing changes Process is extended to simultaneously include multiple GBM detectors (Incl. Na. I and BGO) or other instruments (e. g. , LAT, Swift, etc. ) Simulations and Response / R. M. Kippen (LANL) - 12 - GBM BWG Review, 31 August 2004

How — Response used for Localization Simultaneous spatial/spectral model “hypothesis testing” Trial GRB Direction Observed Det. counts Trial Spectral Parameters Internal response generator Predicted detector counts Chi-square evaluation Spatial/spectral optimization S/C attitude/ position Background model caldb Simulations and Response / R. M. Kippen (LANL) - 13 - GBM BWG Review, 31 August 2004

Development Status ª SIM/DRM development is affected by: l l l Delivery of GBM detector design data/drawings (received June 2004, three months behind original schedule) Delivery of GLAST spacecraft design data/drawings (expected July 2004, three months behind original schedule, initial delivery August 2004) Schedule of GBM calibrations ª Required to verify SIM/DRM s/w and models ª Detector level (MPE), system level (NSSTC), spacecraft level (Spectrum) — all slipped due to launch slip. ª Development status: l l Preliminary versions of GRESS software complete (several months ahead of schedule) Detector model development nearing completion (3 months behind) Spacecraft model development starting (3 months behind) Result: able to meet required delivery schedule Simulations and Response / R. M. Kippen (LANL) - 14 - GBM BWG Review, 31 August 2004

SIM/DRM Revised Delivery Schedule Stable since GBM System CDR June 2004 Milestone Date† Driver Date SIM/DRM Delivery 1 (Det. -level s/w & models) Nov. 1, 2004 ( +4 mo) Verify s/w & models with GBM detector-level calibrations Feb. 2005 – Mar. 2005 SIM/DRM Delivery 2 (Syst. -level s/w & models) Jun. 15, 2005 ( +3 mo) Verify s/w & models with GBM system-level calibrations Jul. 2005 – Sep. 2005 SIM/DRM Delivery 2. 1 (preliminary CALDB/DRM) Nov. 1, 2005 (new) Support IODA Release 2. 2 & 2. 3, and Data Challenge 3 Nov. 1, 2005; Dec. 1, 2005 SIM/DRM Delivery 3 (S/C-level s/w & models) Jan. 2, 2006 ( +3 mo) Verify s/w & models with GBM spacecraft-level source survey Feb. 2006 SIM/DRM Delivery 4 (Ops. phase s/w & models) Apr. 14, 2006 (no change) Support IODA Release 3 (launch-ready software) Sept. 1, 2005 SIM/DRM Delivery 5 (Final DRM/CALDB database) Nov. 1, 2006 (no change) Support Phase E science/Ops. Post-launch * All deliveries from LANL to NSSTC † Schedule changes from ground s/w CDR reflect changes in the GBM calibration schedule (affected by launch slip) Simulations and Response / R. M. Kippen (LANL) - 15 - GBM BWG Review, 31 August 2004

SIM/DRM Schedule Simulations and Response / R. M. Kippen (LANL) - 16 - GBM BWG Review, 31 August 2004