Abstract: On the basis of the MOD10A1, MOD10A2 and HJ-1/CCD data from June to August in 2010 to 2014, with the north slope of Tianshan mountains as the study area, this paper compares and analyzes the snow duration ratio method and the maximum synthesis method in the snowline elevation extraction accuracy and applicability. The results show that snow line height' s error is minimum while snow duration ratio method taking the 40% threshold extraction. Based on confusion matrix method, snow area of HJ-1/CCD is "true value" by the visual interpretation. The results demonstrate that snow duration ratio method to extract snow area's overall accuracy is higher, the accuracy is 98.59% Khat coefficient is 0.90,the accuracy of the maximum synthesis is only 85.29%, Khat coefficient is 0.70. Based on the statistical method, the paper calculated that snow duration ratio method to extract the snowline elevation has higher correlation coefficient of 0.77 with "true value". The average error, error of positive and negative, average absolute error and root mean square error is relatively lower. The maximum synthesis method extracting line height and the same area "true value" has lower correlation coefficient of only 0.54. The average error, error of positive and negative, average absolute error and root mean square error is relatively higher. Using snow duration ratio method to extract the snowline elevation results is better than that of the maximum synthesis method.

Key words: snowline, snow duration ratio method, the maximum synthesis method, the north slope of Tianshan mountains