skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: GLAST Burst Monitor Signal Processing System

Abstract

The onboard Data Processing Unit (DPU), designed and built by Southwest Research Institute, performs the high-speed data acquisition for GBM. The analog signals from each of the 14 detectors are digitized by high-speed multichannel analog data acquisition architecture. The streaming digital values resulting from a periodic (period of 104.2 ns) sampling of the analog signal by the individual ADCs are fed to a Field-Programmable Gate Array (FPGA). Real-time Digital Signal Processing (DSP) algorithms within the FPGA implement functions like filtering, thresholding, time delay and pulse height measurement. The spectral data with a 12-bit resolution are formatted according to the commandable look-up-table (LUT) and then sent to the High-Speed Science-Date Bus (HSSDB, speed=1.5 MB/s) to be telemetered to ground. The DSP offers a novel feature of a commandable and constant event deadtime. The ADC non-linearities have been calibrated so that the spectral data can be corrected during analysis. The best temporal resolution is 2 {mu}s for the pre-burst and post-trigger time-tagged events (TTE) data. The time resolution of the binned data types is commandable from 64 msec to 1.024 s for the CTIME data (8 channel spectral resolution) and 1.024 to 32.768 s for the CSPEC data (128 channel spectral resolution).more » The pulse pile-up effects have been studied by Monte Carlo simulations. For a typical GRB, the possible shift in the Epeak value at high-count rates ({approx}100 kHz) is {approx}1% while the change in the single power-law index could be up to 5%.« less

Authors:
; ; ; ;  [1]; ; ; ; ;  [2]; ; ; ;  [3];  [4];  [5]
  1. University of Alabama, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States)
  2. Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 85748, Garching (Germany)
  3. Marshall Space Flight Center, VP62, Huntsville, AL 35812 (United States)
  4. Los Alamos National Laboratory, ISR-1, MS B244, Los Alamos, NM 87545 (United States)
  5. Southwest Research Institute, Dept. of Space Systems, 6220 Culebra Road, San Antonio, TX 78238 (United States)
Publication Date:
OSTI Identifier:
21067297
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 921; Journal Issue: 1; Conference: 1. GLAST symposium, Stanford, CA (United States), 5-8 Feb 2007; Other Information: DOI: 10.1063/1.2757433; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ALGORITHMS; ANALOG-TO-DIGITAL CONVERTERS; COMPUTERIZED SIMULATION; COSMIC GAMMA BURSTS; COSMIC GAMMA SOURCES; COSMIC PHOTONS; COUNTING RATES; DATA ACQUISITION; DATA PROCESSING; GAMMA DETECTION; INDEXES; KHZ RANGE; MONTE CARLO METHOD; PHOTON EMISSION; PULSES; TELESCOPE COUNTERS; TIME DELAY; TIME RESOLUTION

Citation Formats

Bhat, P Narayana, Briggs, Michael, Connaughton, Valerie, Paciesas, William, Preece, Robert, Diehl, Roland, Greiner, Jochen, Kienlin, Andreas von, Lichti, Giselher, Steinle, Helmut, Fishman, Gerald, Kouveliotou, Chryssa, Meegan, Charles, Wilson-Hodge, Colleen, Kippen, R Marc, and Persyn, Steven. GLAST Burst Monitor Signal Processing System. United States: N. p., 2007. Web. doi:10.1063/1.2757433.
Bhat, P Narayana, Briggs, Michael, Connaughton, Valerie, Paciesas, William, Preece, Robert, Diehl, Roland, Greiner, Jochen, Kienlin, Andreas von, Lichti, Giselher, Steinle, Helmut, Fishman, Gerald, Kouveliotou, Chryssa, Meegan, Charles, Wilson-Hodge, Colleen, Kippen, R Marc, & Persyn, Steven. GLAST Burst Monitor Signal Processing System. United States. doi:10.1063/1.2757433.
Bhat, P Narayana, Briggs, Michael, Connaughton, Valerie, Paciesas, William, Preece, Robert, Diehl, Roland, Greiner, Jochen, Kienlin, Andreas von, Lichti, Giselher, Steinle, Helmut, Fishman, Gerald, Kouveliotou, Chryssa, Meegan, Charles, Wilson-Hodge, Colleen, Kippen, R Marc, and Persyn, Steven. Thu . "GLAST Burst Monitor Signal Processing System". United States. doi:10.1063/1.2757433.
@article{osti_21067297,
title = {GLAST Burst Monitor Signal Processing System},
author = {Bhat, P Narayana and Briggs, Michael and Connaughton, Valerie and Paciesas, William and Preece, Robert and Diehl, Roland and Greiner, Jochen and Kienlin, Andreas von and Lichti, Giselher and Steinle, Helmut and Fishman, Gerald and Kouveliotou, Chryssa and Meegan, Charles and Wilson-Hodge, Colleen and Kippen, R Marc and Persyn, Steven},
abstractNote = {The onboard Data Processing Unit (DPU), designed and built by Southwest Research Institute, performs the high-speed data acquisition for GBM. The analog signals from each of the 14 detectors are digitized by high-speed multichannel analog data acquisition architecture. The streaming digital values resulting from a periodic (period of 104.2 ns) sampling of the analog signal by the individual ADCs are fed to a Field-Programmable Gate Array (FPGA). Real-time Digital Signal Processing (DSP) algorithms within the FPGA implement functions like filtering, thresholding, time delay and pulse height measurement. The spectral data with a 12-bit resolution are formatted according to the commandable look-up-table (LUT) and then sent to the High-Speed Science-Date Bus (HSSDB, speed=1.5 MB/s) to be telemetered to ground. The DSP offers a novel feature of a commandable and constant event deadtime. The ADC non-linearities have been calibrated so that the spectral data can be corrected during analysis. The best temporal resolution is 2 {mu}s for the pre-burst and post-trigger time-tagged events (TTE) data. The time resolution of the binned data types is commandable from 64 msec to 1.024 s for the CTIME data (8 channel spectral resolution) and 1.024 to 32.768 s for the CSPEC data (128 channel spectral resolution). The pulse pile-up effects have been studied by Monte Carlo simulations. For a typical GRB, the possible shift in the Epeak value at high-count rates ({approx}100 kHz) is {approx}1% while the change in the single power-law index could be up to 5%.},
doi = {10.1063/1.2757433},
journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 921,
place = {United States},
year = {2007},
month = {7}
}