SMOS Uni Bonn contributions to SMOS Validation Ralf

SMOS Uni Bonn contributions to SMOS Validation Ralf Lindau Bonn University SMOS Workshop – Hamburg, 9. -10. November 2006

SMOS Bonn contributions § Detection of Radio Frequency Interference - Found in SMMR, AMSR etc. - Expected also in SMOS § Comparison of SMOS soil moisture with existing data - Direct measurements from GSMDB - AMSR-derived SM § Pixel-intern variance - Necessary to interprete the intended validations with point measurements properly. - build and operate a transportable polarized L-Band radiometer § Investigate signal noise due to rain and vegetation SMOS Workshop – Hamburg, 9. -10. November 2006

SMOS Radio Frequency Interference q Time series of 6 GHz brightness temperature from SMMR in France q Until 1981 the normal annual cycle is found. q After 1981 the 6 Ghz signal is completely unusable due to noise. SMOS Workshop – Hamburg, 9. -10. November 2006

SMOS SMMR RFI in 6 GHz The scatter is low in Sibiria, increases westward and reaches maximum values near St. Petersburg SMOS Workshop – Hamburg, 9. -10. November 2006

SMOS ASMR RFI In Europe the 10 GHz channel is completely noisy in England Italy. In the USA the 6 GHz measurements are corrupted over New York, Boulder etc. SMOS Workshop – Hamburg, 9. -10. November 2006

SMOS AMSR 10 GHz RFI 250 K 300 K • RFI is detectable by • high monthly averages • high monthly stddev. SMOS Workshop – Hamburg, 9. -10. November 2006

SMOS Simple RFI Scheme • TB > 260 K • Stddev > • 5 K DTB > 20 K compared to a 10° x 30° surrounding SMOS Workshop – Hamburg, 9. -10. November 2006

SMOS Soil Moisture from AMSR Longtime mean + 10 -day anomalies SMOS Workshop – Hamburg, 9. -10. November 2006

SMOS 2 -Step Retrieval SMOS Workshop – Hamburg, 9. -10. November 2006

SMOS Pixel-intern Variance Belarussian soil moisture data 21 stations, 10 daily during about 10 years Average spatially and compare the reduced variance to the total variance 40% are left for 400 -km-Pixels 59% are left for SMMR-Pixels The left external variance is equal to the maximum correlation between point measurements and area averages SMOS Workshop – Hamburg, 9. -10. November 2006