Table 1. Parameters and Results of the Virtual Validation using Gaussian Dry Spots (Xerops).

#	C		V(obj)	V(psf)	V(obj) + V(psf)	V(image)	Error
1	1	0.00	32.86	36.57	69.43	73.11	3.68
2	1	33.23	32.86	50.12	82.98	86.66	3.68
3	−1	39.88	32.86	54.60	87.46	91.13	3.67
4	2	56.97	32.86	73.77	106.63	110.30	3.67

          The coefficient C and sigma are in microns. All PSF variances are in arcmin². Xerops are sampled at 85x85 points per each lenslet of size 399 micron². The resolution of the SHWFS is 0.11 arcmin. The wavelength is 633nm. The xerop formed at location 4 is assumed to have a negative coefficient, –1, but the radial variance is still positive. error = V(image)-V(obj)-V(psf). When sigma = 0, we use a planar wavefront.