Correlation Map have been published Nature Methods by D. Franke et al. (doi: 10.1038/nmeth.3358). They allow to assess if two saxs curves are the same or not, without needing proper statistical error.
The idea is to measure the longest region where one curve is above the other and to compare it with the total length of the curve.
The statistical probability is derived from: Mark F. Schilling, The College Mathematics Journal, Vol. 21, No. 3, (1990), pp. 196-207 See: http://www.maa.org/sites/default/files/pdf/upload_library/22/Polya/07468342.di020742.02p0021g.pdf