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 DirectionMaximum Distance (arcseconds)Total Distance (arcseconds)
N70 N70
NE50 E, 50 N70
E65 E65
SE45 E, 45 S63
S55 S55
SW45 W, 45 S63
W60 W60
NW45 W, 45 N63
Here is a more graphic presentation of these data:
 NE    70   NW
(50,50) |  (45,45)
 SE     |   SW
(45,45) 55  (45,45) 

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