AO Field Steering Limits

Lick Adaptive Optics

Field Steering Limits

The limits for field steering to acquire off-axis guide stars varies slightly with direction (and alignment).

APD Off-Axis Field Steering Limits

Measured Fall 2002:
all measurements in arcseconds
Note that 55" is the official field steering limit, though in some directions you can field steer futher off axis.

Field Steer Direction	Maximum Distance (arcseconds)	Total Distance (arcseconds)
N	70 N	70
NE	50 E, 50 N	70
E	65 E	65
SE	45 E, 45 S	63
S	55 S	55
SW	45 W, 45 S	63
W	60 W	60
NW	45 W, 45 N	63

Here is a more graphic presentation of these data:

        N                   
 NE    70   NW
(50,50) |  (45,45)
        | 
E65-----|-----60W
        |
 SE     |   SW
(45,45) 55  (45,45) 
        S

Elinor Gates

Last modified: Wed Jan 15 17:14:31 PST 2003