GMB NaI Detector Measured Orientations in Spacecraft Coordinates (Table 1 from C. Meegan et al 2009 ApJ 702 791 )
Detector ID No. | Azimuth (deg) | Zenith (deg) |
0 | 45.9 | 20.6 |
1 | 45.1 | 45.3 |
2 | 58.4 | 90.2 |
3 | 314.9 | 45.2 |
4 | 303.2 | 90.3 |
5 | 3.4 | 89.8 |
6 | 224.9 | 20.4 |
7 | 224.6 | 46.2 |
8 | 236.6 | 90.0 |
9 | 135.2 | 45.6 |
10 | 123.7 | 90.4 |
11 | 183.7 | 90.3 |
The two BGO detectors are oriented at 0 (B0) and 180 (B1) degrees in azimuth, and 90 degrees zenith. B0 is always pointed in the sunward direction. They have a weak dependence on angle, as seen in the figure below.
Locations and orientations of the GBM detectors. (Figure 4 from C. Meegan et al 2009 ApJ 702 791 )
Angular dependence of NaI and BGO detector effective area. (Figures 12 and 13 from C. Meegan et al 2009 ApJ 702 791 )