Time Resolution
0.3–117.2 ms
The gamma-ray burst instrument on each satellite was roughly omnidirectional. Each consisted of a pair of 1.5 inch × 1.5 inch CsI scintillation detectors. A total average count rate during any 0.625 s interval greater than 7-sigma above background triggered the system. Data for the burst, including 0.6 s of pre-trigger data, could have the temporal information recorded in either of 2 ways: for count rates below 1092 ct/s, the total number of counts accumulated in 14.65 ms was recorded. For count rates greater than 1092 ct/s, the time interval required to record 16 counts was recorded with 0.3 ms resolution. There were 4 spectral channels: 0.2–0.3, 0.3–0.4, 0.4–0.6, and 0.6–2.0 MeV. The spectral channels were read every 8 time accumulations. Thus these spectral accumulation times ranged from 2.4 to 117.2 ms. No in-flight calibration was available: The spectral data could be used to search for variability, but not to obtain spectral shapes.
