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Tests on V500 Sun On versus Sun Off 1)Tbmeas. –Tbmodel in the FOV X. Yin, J. Boutin Inputs from R. Balague, P. Spurgeon, A. Chuprin, M. Martin-Neira and.

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Presentation on theme: "Tests on V500 Sun On versus Sun Off 1)Tbmeas. –Tbmodel in the FOV X. Yin, J. Boutin Inputs from R. Balague, P. Spurgeon, A. Chuprin, M. Martin-Neira and."— Presentation transcript:

1 Tests on V500 Sun On versus Sun Off 1)Tbmeas. –Tbmodel in the FOV X. Yin, J. Boutin Inputs from R. Balague, P. Spurgeon, A. Chuprin, M. Martin-Neira and J. Barbosa L1 Sun On and Sun Off (V500 in July, No sun tail, no sun point flags applied) : - OTT - std(Tbmeas. –Tbmodel) - std(Tbmeas. –Tbmodel)/expected radiometric accuracy 2 cases have been studied: -when the sky alias does not appear in the FOV -when the sky alias appears in the FOV

2 When sun alias does not appear in the FOV

3 OTT X pol Ratios of measurement to expected radiometric accuracy Standard deviation of differences between measured and modelled TB Sun on Sun off On - off 10 -10 5 0 1.5 0.5 10 -10 5 0 1.5 0.5 0.2 -0.2 0.2 -0.2 0.2 -0.2 Very flat, no tails at all

4 When sun alias appears in the FOV

5 Sun on Sun off On - off OTT X pol Ratios of measurement to expected radiometric accuracy Standard deviation of differences between measured and modelled TB 10 -10 10 -10 1 5 0 5 0 1.5 0.5 1.5 0.5 0.2 -0.2 0.2 -0.2 Vertical stripes appear in differences of the two OTT, but not very clear in differences of std of TB in the FOV. Negative tails are due to no Sun correction.

6 Sun on Sun off On - off Y pol OTT Ratios of measurement to expected radiometric accuracy Standard deviation of differences between measured and modelled TB 10 -10 5 0 1.5 0.5 10 -10 5 0 1.5 0.5 1 0.2 -0.2 0.2 -0.2

7 November Sun on When reflected Sun alias appears in the FOV Look at std(Tbmeas. –Tbmodel)/expected radiometric accuracy Effect of flagging suntail

8 19 desc Pacific orbits Nov 2010, within 130W-100W/ 0S-20S Long integration Snapshots Xpol 2) Suntails as flagged at L1 not removed 1) Suntails as flagged at L1 removed 1-2

9 19 desc Pacific orbits Nov 2010, within 130W-100W/ 0S-20S 2) Suntails as flagged at L1 not removed 1) Suntails as flagged at L1 removed Long integration Snapshots Ypol 1-2

10 Conclusion If the measurememnts flagged as Suntails are discarded, the ratios between the radiometric accuracy estimated from the std(Tbsmos-Tbmodel) and the expected radiometric accuracy is slightly lower than the case if the measurememnts flagged as Suntails are used. The width of Suntails is not enough for the strong Sun in Nov 2010.

11 J. Boutin, N. Martin, X. Yin, Inputs from R. Balague, P. Spurgeon, A. Chuprin, M. Martin-Neira and J. Barbosa 2) SSS maps derived from L1 v500 and L1 reprocessing commissionning and L2 v500

12 July 2010 L1 v500 Sun Off & Sun On provided by L1 team L2 v500 reprocessed at LOCEAN (sun Off) and at Argans (sun On) Tested L2 flags CTRL_SEL_GP;CTRL_VALID;CTRL_ECMWF = 1 CTRL_NUM_MEAS_MIN;CTRL_MANY_OUTLIERS;CTRL_SUNGLINT;CTRL_MOONG LINT;CTRL_GAL_NOISE;CTRL_REACH_MAXITER;CTRL_MARQ;CTRL_CHI2_P;CTR L_CHI2;CTRL_SUSPECT_RFI = 0 |Xswath| < 300km (better RFI sorting) 3<=WS<=12m/s SSS MAPS: Data Processing

13 SSS maps computation 1°x1° SSS maps computed from averages of SMOS SSS weighted by their spatial resolution R 2 and variance of the error  2 (derived by the retrieval):

14 L1 v500 sun off L1 Commissionning Reprocessing L2 v500 Ascending swaths SSS Center swath July ISAS-ARGO SSS v500 sun off - ISAS

15 L1 v500 sun off L1 v500 Sun on or Sun off & L2 v500 Ascending swaths SSS Center swath July L1 v500 sun on In July, some differences between Sun Off and Sun On but how to discriminate which one is the best (sun impact is low after applying sun point & sun tail flags)!!

16 Ascending Descending July, 2010, v500, Sun_on July, 2010, v500, Sun_off SSS(all WS) SSS SMOS - ISAS/ARGO Center swath – July 2010 Differences between Sun On and Sun Off < ascending –descending! (large stripes on descending (OTT from asc orbits only (sun_off) or from asc+desc (sun on) applied to asc and desc

17 Comparison with ARGO L2 V317-August 2010 SMOS -CLIMATOARGO -CLIMATO SMOS-ARGO SSS anomalies seen by ARGO in tropical Pacific seen by SMOS but Pbs close to land, ice Pbs at high wind speed (see next slide), anomaly in Pacific ITCZ more negative on SMOS Boutin et al., subm, 2011

18 Comparison with ARGO L1 ~v500 – L2 V500 - July 2010 SMOS -CLIMATO ARGO -CLIMATO SMOS-ARGO SSS too high in the Southern Ocean/ close to ice, too low close to land

19 Ascending orbits (center of orbit) 3<WS<12m/s Colocations with ARGO (+/-50km; +/-10days) South Pacific:  SSS =0.09+/-0.56 N=160 ITCZ trop Pac N:  SSS =-0.18+/-0.44 N=236 South Indian:  SSS =0.11+/-0.46 N=50 Subtropical Atl N:  SSS =0.1+/-0.35 N=59 Before v500 August 2010 V500 Sun Off - OTT asc July 2010 South Pacific:  SSS =0.16+/-0.63 N=186 ITCZ trop Pac N:  SSS =-0.05+/-0.40 N=248 South Indian:  SSS =0.06+/-0.56 N=52 Subtropical Atl N:  SSS =0.02+/-0.22 N=69 V500 Sun On OTT asc+desc July 2010 South Pacific:  SSS =0.27+/-0.70 N=170 ITCZ trop Pac N:  SSS =0.01+/-0.43 N=230 South Indian:  SSS =0.21+/-0.55 N=48 Subtropical Atl N:  SSS =0.19+/-0.22 N=65 Comparison with ARGO: No clear improvement of v500 on ascending orbits when dealing with resolution of 10 days-100km during one month (except close to land).


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