Meetings: 2012 Aquarius Calibration/Validation Workshop

March 26-28, 2012
Santa Rosa, CA USA
The Aquarius Calibration/Validation Workshop took place in Santa Rosa, California in late March 2012. The objectives of the two day workshop were to (1) assess radiometer calibration performance, (2) review the RFI mitigation algorithms, (3) review scatterometer calibration performance and algorithm, (4) review the geophysical correction algorithms and performance, and to make decisions on the path towards Aquarius data Version 1.4 processing.
Agenda
Documents: 26
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Meissner, T., Wentz, F. and Lagerloef, G. [26-Mar-12]. Ascending and descending biases were found to correlate with S3 and can largely be removed by adjusting x-pol coupling from S3 into Q. Residual ascending/descending biases do not appear to be persistent in time, strictly zonal, due to diurnal SST or diurnal ATM.
Yueh, S. [26-Mar-12]. An introduction to the Aquarius Calibration and Validation workshop, including workshop goals and schedule.
Meissner, T. and Wentz, F. [27-Mar-12]. A walk-through of the salinity retrieval algorithm for Version 1.3., including the differences between the current version and V1.1.
Fore, A. [27-Mar-12]. Results from Cross-Pol Calibration are presented. Faraday rotation correction seems to be improved when using the radiometer Faraday angle instead of model.
Xu, X. and Yueh, S. [28-Mar-12]. Land data, binned to the SMAP grid map, was examined to determine whether freeze and thaw conditions could be detected. Maps of freeze/thaw conditions were produced.
Brown, S. and Misra, S. [26-Mar-12]. This work uses on-earth calibration targets for stability tracking, namely Antarctica and a location in the rainforest. Antarctic and Rainforest trend estimates consistent with a gain drift in the Aquarius radiometer (e.g. noise diode). The next steps are to continue model development for both regions to increase fidelity as well as continue tracking the Aquarius performance.
Scott, J. [28-Mar-12]. Presented at the 2012 Aquarius Calibration/Validation Workshop in Santa Rosa, CA.
Jones, L. and Hejazin, Y. [28-Mar-12]. This presentation describes the approach used to derive an ocean roughness correction for Aquarius. This correction involves using the microwave radiometer's brightness temperature to infer Ka-band ocean roughness. This is translated into L-band using an ocean surface emissivity radiative transfer model.
Neumann, G., Yueh, S., Fore, A., Freedman, A., Hayashi, A., and Tang, W. [27-Mar-12]. An analyis of the stability of the Aquarius scatterometer. In this analysis, no significant long-term trend was seen in the predicted vs. measured Sigma0.
Bindish, R. [28-Mar-12]. The baseline soil moisture algorithm uses the radiative transfer equation (t-w model) and H pol observations along with ancillary data to estimate soil moisture. A difference between the Aquarius and SMAP implementation is the need to incorporate incidence angle effects.
Kao, H-Y., Lagerloef, G. and Carey, D. [26-Mar-12]. The trends of Aquarius salinity measurements for all beams were compared between Version 1.2.2 and 1.2.3.
Kim, S-B., Chan, S., Yueh, S., and Lee, J-H. [28-Mar-12]. Presented at the 2012 Aquarius Calibration/Validation Workshop in Santa Rosa, CA.
Freedman, A. [27-Mar-12]. Reviewing the results of Cold Sky Calibration (CSC), several scatterometer bumps were observed. The origin and impact of these bumps are discussed.
Dinnat, E., Le Vine, E. and Abraham, S. [27-Mar-12]. A quick look at the Cold Sky Calibration (CSC) efforts, and a comparison of the results to simulations.
Vandemark, D. and Feng, H. [28-Mar-12]. Presented at the 2012 Aquarius Calibration/Validation Workshop in Santa Rosa, CA.
de Matthaeis, P., Le Vine, D., and Piepmeier, J. [27-Mar-12]. The status of the radiometer RFI flagging algorithm performance are presented, as well as a status for what issues have already been addressed. The recently-discovered issue of short accumulations is investigated, and its potential for correction are discussed.
Bindish, R. [26-Mar-12]. Aquarius observations compare well with SMOS observations. There is some scatter, possibly due to RFI in SMOS and Aquarius, as well as the heterogeneous footprint and different azimuth angles.
Meissner, T. and Wentz, F. [27-Mar-12]. Presented at the 2012 Aquarius Calibration/Validation Workshop in Santa Rosa, CA.
Freedman, A. [27-Mar-12]. Proxy measurement datasets are presented for polar sea ice. Two measurements appear to be best for sensing sea-ice cover: Sigma-0 VV / Sigma-0 HH ratio and Noise-equivalent Sigma-0 (HH or VV). Other measurements are significantly influenced by RFI or other geophysical variables.
Freedman, A. [26-Mar-12]. A variety of remaining observations and issues are presented, including a look at inclination angles, monitoring loopback power, and drift in echo.
Tang, W., Yueh, S., and Hayashi, A. [27-Mar-12]. The ascending and descending passes of Aquarius have had an observed difference. The question posed here is whether ocean surface rain could explain some of the ascending/descending asymmetry that has been observed.
Yueh, S. [28-Mar-12]. Aquarius data collected near the galactic plane allows for the recovery of ocean wave slope. The retrieved wave slope improves sea surface salinity retrieval by about 1 psu near the galactic plane, under light wind conditions.
Ruf, C. and Chen, D. [27-Mar-12]. An assessment of the state of radio frequency interference (RFI) and its affect on the Aquarius signal.
Wentz, F.J. and Meissner, T. [27-Mar-12]. This talk concerns the reflected galactic radiation, a large scale signal that is complex and subject to modeling errors. Complete validation of galaxy reflection tables will likely require multiple years of observations to complete.
Melnichenko, O., Hacker, P., Maximenko, N., and Potemra, J. [26-Mar-12]. Are small scale features real, and to what degree are they a product of ascending/descending and inter-beam biases?
Piepmeier, J. [26-Mar-12]. The focus of this talk is whether or not signatures of observed deflection ratios can be reproduced. The current calibration model, RF model, and deflection ratios are investigated, and a potential for improvement is presented.