PART 1: A Brief Comparison of Time- Latitude First Stokes Bias Structure in v505 and v620 PART 1: A Brief Comparison of Time- Latitude First Stokes Bias Structure in v505 and v620 Joe Tenerelli SMOS Calibration Meeting 18 26/05/2014

PURPOSE: Compare v504 and v620 alias-free average bias structure as a function of time and latitude, focusing on May 2011 (not eclipse period with relatively small orbital drift in v504) and Nov 2012-Jan 2013 (eclipse period).

Recall Descending Pass TP-7 in Eclipse Period Variations in Tp7 strongest during this time of year:

Corresponding v505 AF-FOV Bias in (Tx+Ty)/2 Variations in first Stokes parameter also strongest during this time of year in version 504 of reconstructed Tbs:

Corresponding v620 AF-FOV Bias in (Tx+Ty)/2 Drift noticeably reduced in v620:

Change from v505 to v620 Bias Drift difference between v620 and v504:

Recall Descending Pass TP-7 in Eclipse Period Bias change pattern seems to correspond well to the Tp-7 pattern in descending passes. So is the change in the bias linked to the removal of the one-slope model?

Descending Pass Bias vs TP-7 Correlation between Tp7 and bias in first Stokes is reduced in V620 rtelative to that in v504:

We next look at ascending pass bias

v505 AF-FOV Bias in (Tx+Ty)/2 Ascending passes

Corresponding v620 AF-FOV Bias in (Tx+Ty)/2 Ascending passes

Change from v505 to v620 Bias Ascending passes

CONCLUSION FOR ASCENDING PASSES: Latitudinal variation also seems reduced for ascending passes in the eclipse period.

We next look at descending-ascending pass bias

v505 AF-FOV Bias in (Tx+Ty)/2 Descending-Ascending passes

Corresponding v620 AF-FOV Bias in (Tx+Ty)/2 Descending-Ascending passes

Change from v505 to v620 Bias Descending-Ascending passes

We next look at May 2011 where the change is mostly an overall shift in the level of the brightness temperature with little latitude- time structure.

Corresponding v505 AF-FOV Bias in (Tx+Ty)/2 May 2011 descending passes

Corresponding v620 AF-FOV Bias in (Tx+Ty)/2 May 2011 descending passes

Change from v505 to v620 Bias May 2011 descending passes

We next look at ascending pass bias for May 2011

Corresponding v505 AF-FOV Bias in (Tx+Ty)/2 May 2011 ascending passes

Corresponding v620 AF-FOV Bias in (Tx+Ty)/2 May 2011 ascending passes

Change from v505 to v620 Bias May 2011 ascending passes

CONCLUSION FOR MAY 2011 ASC/DESC PASSES: Noticeable decrease in long-term drift in v620 relative to v504 for ascending passes. Little short term drift in either version in this period.

Fourth Stokes Bias

Fourth Stokes v505 Bias

Fourth Stokes v620 Bias

Fourth Stokes v620-v505 Bias

CONCLUSION FOR FOURTH STOKES: Reduced short term drift. Less obvious correlation with Faraday rotation (should be none).