Aquarius Algorithm Meeting

1. Aquarius Algorithm Meeting To Do Lists

2. From Frank Wentz: • Implement Ruf RFI flagging • Implement other QC flags • Further test review, and finalize radiometer sensor model • Adapt geolocation to handle of orbit-maneuvers • Implement galactic radiation into simulation and L2b algorithm • Implement solar backscatter into L2b algorithm • For the next year, there will be continual updates and improvements

3. From Jeff Piepmeier To be completed –Computation and verification of impedance mismatch correction –Computation of losses from band-integrated S-parameters –Testing of Long Accumulation (LA) “feature” corrections –TND estimates using P&M from R3 test –Verification of temperature dependent calibration of P & M –Incorporate complex impedance mismatch between feed and R5? –Document!!!!!

4. From Thomas Meissner: Implement RFI filter by C. RufFORTRAN code is a simple double-mean filter. What happened with all the elaborate static and dynamic auxiliary data?What happened with the time tagging? Clarification of analytic form for temperature correction for L4 and L5 (J. Piepmeyer)? Impedance mismatch in zone 5 (J. Piepmeyer)?

5. From Frank Wentz: Subroutine count_to_ta Embedded in the routine is currently a placeholder for RFI detection. Chris Ruf recently delivered RFI detection code that we will implement in the coming weeks. Work To Be Done • Continue to Analysis 2007 Simulation Results to better Understand the Problem we are facing • Implement ancillary data routines for obtaining Solar Flux and “real-time” salinity. • Upgrade simulator to process data on a daily basis and send to ADF. • Generate TA Galaxy Reflection Tables for Rough Ocean Surfaces • Generate Land Correction Tables • Implement flags into the L2 data. • Implement moon in antenna main lobe • And, all the things I have forgotten

6. David Le Vine: Faraday Rotation Plan • Test • SMOS “full-pol” data • Remove spurious signals • Filter at land/water boundaries • Match to theoretical profile • Magnetic field + estimate of TEC • Remove bias • Match ground truth (sounder) at selected locations • Backup Plan • Use model (data assimilation) • Correct for altitude (SMOS algorithm)

7. From David Le Vine re Science Algorithm: • Things Remaining to be Added • Gain glitch filter • Roughness model for reflected galactic background • Sun correction when in daylight and when backscatter occurs from small scale roughness • Land correction (Land fraction will be flagged but no correction in the October code)

8. From John Gunn: AVDS – to do Year-long simulation matchups ADPS interface setup (update ICD) R/T model matchups S/W configuration control CPA, weighted average processing

9. From Shannon Brown: We will perform studies to assess the calibration of the Aquarius and MWR radiometers and validate the retrievals Develop an empirical L-band rough surface emission model and use it to develop roughness correction algorithms

10. From Linwood Jones: Future Pre-launch Activities • MWR radiometric calibration • Deliver to CONAE independent analysis of TV radiometric calibration • Deliver to CONAE post-launch radiometric calibration algorithms • MWR L1/L2 simulation • Deliver forward radiation transfer model • Deliver V-0 wind speed retrieval ATBD • Deliver V-0 rain rate retrieval ATBD • Develop preliminary AQ roughness correction algorithm

11. From Gary Lagerloef: Insert arbitrary biases in all 12 channels Simulate arbitrary drifts in all 12 channels Orbit harmonics calibration drifts (1-4 harmonics, e.g.) Simulate a complete cold sky maneuver Solar flare RFI Attitude offsets

12. From Gary, continued • Channel failure • H or V channel • P or M channel • Other suggestions … lunar, bi-static solar reflection, diffuse galaxy refl.

13. From Simon Yueh et al. (L2 scatterometer processing) • Antenna patterns: • The cross-talk from the theory and scale-model antenna patterns seems to be significantly different. • Will the cross-talk in the as-flown configuration differ from both the theory and scale-model patterns? • The error estimate for Faraday rotation correction needs to be analyzed for nominal ionospheric TEC, not worst case. • We need to develop a strategy to determine antenna patterns post-launch

14. From Simon Yueh et al. (L2 scatterometer wind) • Derivation of model function from the data. • Re-perform the analysis using averaged wind over 3-dB footprint as the truth for training • Comparison of predicted σwind to observed RMSE of retrieved wind as compared to beam center wind. • Use individual polarizations to retrieve winds after calibration of individual channels.

15. From Simon Yueh et al. (L2 scatterometer delta TB) • The wind speed - ΔTB coefficients will be updated with Aquarius data after launch.

16. From Simon Yueh et al. (scatterometer model function) • This work is still in progress; we need to do much more: • From simulated data we will determine how much data we need to generate the model function. (we have the whole year of scat data processed to L2). • Tune the temporal offset to match expected RMS wind speed and direction errors of NCEP. (6h offsets may be too much – I computed ~ 30deg of rmse in direction).

17. From Simon Yueh et al. (scatterometer L1A to L2 algorithm) • Synchronizing radiometer and scatterometer data using? • Block ID • Time tag • Location beam center • Transfer of Faraday Rotation information between rad and scat • Development and testing of off-nominal processing capabilities • Part of pre-launch testing • Errors in position, pointing, cold-sky operation • Who generates simulated data sets? When? • Model improvements • Before launch: Using simulated data • After launch: procedures and timelines, using actual data • L2 data flagging • How should flagged data be processed or represented? • Rain flag source? • Radiometer/Scatterometer consistency in L2 products?

18. From Simon Yueh et al. • Scat vs Rad L1A Comparison Who will do these comparisons and checks? When? L1B, L2?

19. From Simon Yueh et al. Open Issues • Antenna Pattern cross-pol leakage for accurate recovery of cross-pol terms • Does not affect primary algorithm using total power products • Science analysis tools • Time series analysis for ground calibration locations • Crossover analysis • Land/ocean crossing & pointing verification • Geographic plotting and ancillary data-set overlays

20. Fred Patt: What We Need • Approval of the current Level-1A to 2 software implementation to support the year-long and mission simulations. • Agreement on the time frame to start the mission simulation. • Agreement on the ancillary data sets and sources. • Agreement on the Level-2 parameters for the simulations. • Schedule and responsibility for algorithm and software updates between now and launch.