(a) 
(b) 


(c)

 Fig 10. Topography of the North (a) and South (b) sector panels before and after correction. RMS surface error is 1.2 mm and 0.18mm correspondingly. Repeatability of  successively measured maps is 0.06  mm.(V.Khaikin,S.Golosova, F.Danilevich et al. XX ESTEC Antenna Workshop, June 1997). (c) Histogram of surface errors of RATAN-600 South sector panels after surface reconstruction.