A Validation of MODIS Snowcover Products in Romania: Challenges and Future Directions

Abstract

The MODIS snowcover product is one of many geophysical products derived from MODIS data. A cross-validation of the MODIS snowcover daily products with data obtained from the meteorological network stations was conducted for the entire territory of Romania. The validation time interval covered the period between 29 October, 2004 and 1 May, 2005. The overall accuracy for the whole set of cloud-free useful data proved to be 95%. The validation time interval included the three common snow situations: (1) late autumn months where 37.1% of the initial set of the data was used, and the overall accuracy was 98.6%; (2) the “winter” months where the clouds reduced the set of useful data – 31.75%– and the overall accuracy was 93.7%; and (3) the months of February and March which returned the highest accuracy (> 95%). Additionally, a cross-validation using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) high-resolution imagery was carried out. Furthermore, the MODIS, meteorological data and ASTER data were integrated into a Geographic Information System (GIS) environment to perform flexible and comprehensive cross-checking followed by a thematic analysis based on additional sets of data such as digital elevation models (DEMs) and land-cover datasets.