The automatic guide star parameters used by the 2013A PIT for conditions CC50, IQ70, and SB50 are given in Table 1. These are modified for the conditions by the values in Table 2. The UCAC3 catalog is queried using the parameters given for the instrument/mode given in the observation. The UCAC3 magnituide f.mag is compared with the R-magnitude limits from the tables. For the GMOS and FLAMINGOS-2 OIWFS wavefront sensors (WFS) and GeMS Canopus WFS a complete range of PAs is checked and the fraction of steps with valid guide stars in the WFS patrol field is returned. The GeMS algorithm searches for 2 or 3 star Canopus (CWFS) asterisms with one ODGW flexure compensation star.
Table 1. Standard guide star query parmaters.Â
| Instrument | Guider | Mode | Min Radius ['] | Max Radius ['] | Min mag | Max mag | Bandpass | Â | Â | |
| GMOS-N/S | PWFS2 | Non-sidereal | 5.3 | 6.95 | 9.0 | 14.5 | R | Â | ||
| NIRI | PWFS2 | f/6 | 5.2 | 6.95 | 9.0 | 14.5 | R | Â | ||
| NIRI | PWFS2 | f/14 | 4.8 | 6.95 | 9.0 | 14.5 | R | Â | ||
| NIRI | PWFS2 | f/32 | 4.3 | 6.95 | 9.0 | 14.5 | R | Â | ||
| NIFS | PWFS2 | Â | 4 | 6.95 | 9.0 | 14.5 | R | Â | ||
| GNIRS | PWFS2 | Â | 4.8 | 6.95 | 9.0 | 14.5 | R | Â | ||
| Michelle | PWFS2 | chopping | 4.8 | 6.95 | 7.5 | 13.0 | R | Â | ||
| T-ReCS | PWFS2 | chopping | 4.8 | 6.95 | 7.5 | 13.0 | R | Â | ||
| Â | Â | Â | Â | Â | Â | Â | ||||
| NIRI | PWFS1 | f/14 | 5.3 | 6.95 | 9.0 | 14.5 | R | Used for LGS+PWFS1 | Â | |
| NIRI | PWFS1 | f/32 | 4.8 | 6.95 | 9.0 | 14.5 | R | Used for LGS+PWFS1 | Â | |
| NIFS | PWFS1 | Â | 4.8 | 6.95 | 9.0 | 14.5 | R | Used for LGS+PWFS1 | Â | |
| GNIRS | PWFS1 | Â | 4.8 | 6.95 | 9.0 | 14.5 | R | Used for LGS+PWFS1 | Â | |
| Â | Â | Â | Â | Â | Â | Â | ||||
| FLAMINGOS-2 | F2 OIWFS | Â | 0.33 | 6.1 | 9.5 | 15.0 | R | OI geometry used, PAs checked | ||
| GMOS-N/S | GMOS OIWFS | Sidereal | 0.33 | 4.8 | 9.5 | 15.5 | R | OI geometry used, PAs checked | ||
| NICI | NICI OIWFS | Â | Â | Â | Â | Â | Assumes target is always guidestar | |||
| Altair | AOWFS | Natural Guide Star | 0 | 0.45 | -2.0 | 15.0 | R | AOWFS geometry used | ||
| Altair | AOWFS | Laser Guide Star | 0 | 0.45 | -2.0 | 18.0 | R | AOWFS geometry used | ||
| Canopus |
CWFS |
Laser Guide Star |
0 | 1.15 | 8.0 | 18.0 | R | Searches for 2 or 3 star asterisms |
||
Table 2. Conditions-dependent corrections to guide star magnitude limits.
|  Conditions | Delta mag |
Bandpass |
| Â CC50 | Â 0.0 | Â All |
| Â CC70 | Â -0.3 | Â All |
| Â CC80 | Â -1.0 | Â All |
| Â CCAny | Â -3.0 | Â All |
| Â IQ20 | Â +0.5 | Â R |
| Â IQ70 | Â 0.0 | Â R |
| Â IQ85 | Â -0.5 | Â R |
| Â IQAny | Â -1.0 | Â R |
| Â SB20 | Â 0.0 | Â R |
| Â SB50 | Â 0.0 | Â R |
| Â SB80 | Â -0.3 | Â R |
| Â SBAny | Â -0.5 | Â R |
