TY - GEN AU - Santi,Emanuele AU - Paloscia,Simonetta TI - Microwave Indices from Active and Passive Sensors for Remote Sensing Applications SN - books978-3-03897-821-3 PY - 2019/// PB - MDPI - Multidisciplinary Digital Publishing Institute KW - time series analysis KW - passive microwave soil moisture KW - Sentinel-1 and Sentinel-2 KW - Snow Depth and Snow Water Equivalent KW - snow cover characteristics KW - vegetation biomass KW - roughness KW - sea ice KW - SMOS KW - microwave radiometry KW - soil moisture downscaling KW - Vegetation Biomass KW - vegetation index KW - Terra MODIS KW - Sentinel-1 KW - Microwave Indices KW - soil moisture content KW - dual-frequency ratios KW - SMAP KW - passive microwave KW - water-cloud model KW - snow KW - Sentinel-1 backscatter KW - AMSR2 KW - data fusion KW - microwaves KW - mountain region KW - SAR KW - start of season KW - crops KW - NDVI KW - scatterometer KW - Radarsat-2 KW - polarization KW - vegetation water content KW - co-pol ratio KW - active microwaves KW - microwave indices KW - harvest KW - Microwave Radiometry KW - soil moisture KW - Soil Moisture Content KW - snow correlation length KW - radiometer KW - radar KW - soil scattering KW - vegetation descriptor KW - scale gap KW - snow water equivalent N1 - Open Access N2 - Past research has comprehensively assessed the capabilities of satellite sensors operating at microwave frequencies, both active (SAR, scatterometers) and passive (radiometers), for the remote sensing of Earth's surface. Besides brightness temperature and backscattering coefficient, microwave indices, defined as a combination of data collected at different frequencies and polarizations, revealed a good sensitivity to hydrological cycle parameters such as surface soil moisture, vegetation water content, and snow depth and its water equivalent. The differences between microwave backscattering and emission at more frequencies and polarizations have been well established in relation to these parameters, enabling operational retrieval algorithms based on microwave indices to be developed. This Special Issue aims at providing an overview of microwave signal capabilities in estimating the main land parameters of the hydrological cycle, e.g., soil moisture, vegetation water content, and snow water equivalent, on both local and global scales, with a particular focus on the applications of microwave indices UR - https://mdpi.com/books/pdfview/book/1730 UR - https://directory.doabooks.org/handle/20.500.12854/53452 ER -