Abstract. The snow cover products of optical remote sensing systems
play an important role in research into global climate change, the
hydrological cycle, and the energy balance. Moderate Resolution Imaging
Spectroradiometer (MODIS) snow cover products are the most popular datasets
used in the community. However, for MODIS, cloud cover results in spatial
and temporal discontinuity for long-term snow monitoring. In the last few
decades, a large number of cloud removal methods for MODIS snow cover
products have been proposed. In this paper, our goal is to make a
comprehensive summarization of the existing algorithms for generating
cloud-free MODIS snow cover products and to expose the development trends.
The methods of generating cloud-free MODIS snow cover products are
classified into spatial methods, temporal methods, spatio-temporal methods,
and multi-source fusion methods. The spatial methods and temporal methods
remove the cloud cover of the snow product based on the spatial patterns and
temporal changing correlation of the snowpack, respectively. The
spatio-temporal methods utilize the spatial and temporal features of snow
jointly. The multi-source fusion methods utilize the complementary
information among different sources among optical observations, microwave
observations, and station observations.