Disclosed is a method of measuring a target on a substrate using a metrology tool comprising an illumination source operable to emit an illumination beam for illuminating the target and a metrology sensor for collecting the scattered radiation having been scattered by the target. The method comprises calculating a target angle based on cell dimensions of a unit cell of said target in a first direction and a second direction orthogonal to said first direction; and order numbers of a selected pair of complementary diffraction orders in said first direction and second direction. At least one pair of measurement acquisitions is performed at a first target orientation and a second target orientation with respect to the illumination beam, wherein said target angle for at least one of said at least one pair of measurement acquisitions is an oblique angle.