国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Preparation for Vicarious Calibration of SMOS using Takelimgan Sand Desert Weiguo ZHANG, Ji WU, Heguang LIU, Chuandong XU, Dihui LI, Hao LIU, Jingshan JIANG

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Contents 1. Revisit of AMSR-E data over the desert 2. The first Takelimgan field experiment 3. Consideration for commissioning phase campaign

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 AMSR-E data over the desert Stdev of errors: V Pol. 0.98KStdev of errors: H Pol. 1.40K Data of the 2 nd half year of 2005,10GHz The same dataset as used in optimization (AMSR-E data nicely provided by NSIDC.org by ftp)

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 AMSR-E data over the desert Comparison of observed and simulated Tb AFTER calibration of H Pol. 10GHz Bias: Stdev of Errors: K Comparison of observed and simulated Tb BEFORE calibration of H Pol. 10GHz (Stdev of errors: H Pol. 1.40K) Calibration Data of the 2 nd half year of 2005

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 AMSR-E data over the desert Data of the whole year of 2006 Something Wrong! Calibration whole year H pol. Simulation AMSRE Observation Something Wrong! More scattered Less scattered after calibration The Simulation method and calibration formula can be extended in time scale readily provided the instrument is stable.

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Quick Response to Spaceborne Radiometer Behavior Something Wrong Here!

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Can this simulation method and parameters be extended to other frequencies? 6.9GHz data simulated with the same method and parameters as for 10GHZ V. Pol. H. Pol.

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Can this simulation method and parameters be extended to other frequencies? 19GHz data simulated with the same method and parameters as for 10GHZ V. Pol. H. Pol.

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Implication to SMOS Cal/Val Activities By excluding rainy days and obviously unreasonable observations, Tb of the desert can be simulated with an accuracy within 1K both for V and H pol. Currently at 10GHz. L band is supposed to be more stable. Some unreasonable fluctuation (such as that exists in AMSR-E H pol.) can be identified and calibrated. Strange behavior of the sensor can be easily identified. The simulation, calibration method and parameters can be readily extended in time scale. An intensive commission phase activities can do very much works to monitor its whole life cycle. The simulation, calibration parameters for one frequency should not be extended to other frequencies without further investigation. But it seems the methods can be readily adopted by other frequencies. Investigation specially designed for L band is urgently needed.

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 The first Takelimgan field experiment The experiment is carried out during 20/07/ /08/2007, actual works was done during 25/07/ /08/2005, 18 days. The main purpose of the experiment is to measure soil moisture profile and distribution in an extent that can represents an average status near the center of the desert. Soil temperature profile is measured for obviously reason. Two frequencies(6.6, 10.7GHz) radiometer is used to measure Tb of the desert in order to find what would be necessary and important with an L band campaign in mind.

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Partner with tough job

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Background info about the site

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Sand Dunes

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Soil moisture profile measurement

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Soil temperature profile measurement Calibration curves

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Soil Moisture and temperature sample points

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Radiometer Setup

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Ground Truth

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Data Process ongoing

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Consideration for Commissioning phase Campaign

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Multiple angular simulation Roughness not considered

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Commissioning phase campaign 50Km The scale may not be exact. Three sets of Soil temperature profile sensors at every points. (100 sets in all, 10 for backup) Equipped before radiometer Operation. Data should be Recorded by automatic recorder. Wire based data recorder is preferred. Soil moisture profile beyond 2 m Should be investigated. Truck mounted radiometer needs to continuously observe sand dunes with different observation angle, azimuth angle and position at every points for two days. All 90 points may take 2 months to complete. Then tower observation. After that, soil temperature profile data should be collected from the data recorder once a week until commissioning phase finished. It may cost 3million RMB$.

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 L-band Radiometer Architecture Prospect System Parameter: Central Freq ： GHz 3db Bandwidth ： 19 MHz （ 1.404~1.423 GHz ） Noise Figure ： 3 dB Antenna Beamwidth: ～ 15 o ( In development ) Nicely provided by Hao LIU

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Summary We aim at provide an absolute brightness temperature tie point to be used for SMOS calibration, including long term and short term, especially at hot end. The accuracy is expected to be 1K according to AMSR-E analysis. It is possible but much works need to do. Intensive commissioning phase campaign with an stable and accurate L band radiometer is necessary for absolute brightness temperature evaluation. Drift, unreasonable fluctuation during the whole life cycle can be readily monitored after a successful campaign.

国家 863 计划微波遥感技术实验室 The National Microwave Remote Sensing Laboratory 11/15/2007 Thanks for attention!