Polarization of proton beam in the Brookhaven Alternating Gradient Synchrotron is preserved
during acceleration by use of two helical dipole partial snake magnets. These magnets modify
the spin tune to avoid strong intrinsic resonances associated with the vertical betatron motion,
but in the process excite many weaker resonances associated with the horizontal betatron motion.
Since these resonances occur at the same frequencies as resonances from betatron coupling, they
may be corrected by introducing coupling resonances of equal and opposite amplitude. Fifteen
pulsed skew quadrupoles have been added to the AGS lattice in order to implement such a
correction scheme. We describe the correction principle, its implementation and commissioning
results.