Title
Quantifying Uncertainties in Land-Surface Microwave Emissivity Retrievals
Abstract
Uncertainties in the retrievals of microwave land-surface emissivities are quantified over two types of land surfaces: desert and tropical rainforest. Retrievals from satellite-based microwave imagers, including the Special Sensor Microwave Imager, the Tropical Rainfall Measuring Mission Microwave Imager, and the Advanced Microwave Scanning Radiometer for Earth Observing System, are studied. Our results show that there are considerable differences between the retrievals from different sensors and from different groups over these two land-surface types. In addition, the mean emissivity values show different spectral behavior across the frequencies. With the true emissivity assumed largely constant over both of the two sites throughout the study period, the differences are largely attributed to the systematic and random errors in the retrievals. Generally, these retrievals tend to agree better at lower frequencies than at higher ones, with systematic differences ranging 1%-4% (3-12 K) over desert and 1%-7% (3-20 K) over rainforest. The random errors within each retrieval dataset are in the range of 0.5%-2% (2-6 K). In particular, at 85.5/89.0 GHz, there are very large differences between the different retrieval datasets, and within each retrieval dataset itself. Further investigation reveals that these differences are most likely caused by rain/cloud contamination, which can lead to random errors up to 10-17 K under the most severe conditions.
Year
DOI
Venue
2014
10.1109/TGRS.2013.2244214
IEEE T. Geoscience and Remote Sensing
Keywords
Field
DocType
random errors,remote sensing,systematic errors,microwave radiometry,earth observing system,tropical rainfall measuring mission microwave imager,rain-cloud contamination,brightness temperature,special sensor microwave imager,measurement uncertainty,systematic error,advanced microwave scanning radiometer,random error,land-surface emissivity,satellite-based microwave imagers,atmospheric radiation,tropical rainforest,land-surface microwave emissivity retrievals,microwave,systematics,uncertainty,cloud cover,emissivity,atmosphere,rain forests
Microwave,Satellite,Brightness temperature,Remote sensing,Atmospheric sciences,Microwave imaging,Special sensor microwave/imager,Emissivity,Mathematics,Cloud cover,Radiometer
Journal
Volume
Issue
ISSN
52
2
0196-2892
Citations 
PageRank 
References 
6
0.69
9
Authors
9