Based on the surface elevation profiles of sea ice in the Weddell Sea measured by a helicopter-borne laser altimeter during the Winter Weddell Outflow Study 2006, an optimal model is established with the relative deviations between the theoretical and measured ridge height (spacing) distributions as the performance index and the cutoff height as a control variable. An optimal cutoff height of 0.62 m is obtained and used to separate ridges from level ice surface. Analysis on the ridge distributions implies that the best fits to the observed sail height and spacing distributions are achieved by W'80 distribution and a lognormal distribution, respectively. All profiles are clustered into three regimes by the k-means algorithm based on the ridging intensity R i (R i &le 0.01, 0.01 < R i &le 0.026 and R i > 0.026). The average sail height is 0.99 m for the profiles of R i &le 0.01, 1.12 m for 0.01 < R i &le 0.026, and 1.17 m for R i > 0.026. While the average spacing are 232m, 54 m and 31 m respectively for the three different regimes. Effective thickness within the area covered by ridged ice, average thickness of ridged ice, sail cross-section, and the areal fraction of ridged ice are also calculated by the mathematical models, and the results indicate that these parameters increase with increase of the ice ridge intensity.