Forward model and Jacobians for Tropospheric Emission Spectrometer retrievals
IEEE Transactions on Geoscience and Remote Sensing 44:5 (2006) 1308-1323
Abstract:
The Tropospheric Emission Spectrometer (TES) is a high-resolution spaceborne sensor that is capable of observing tropospheric species. In order to exploit fully TES's potential for tropospheric constituent retrievals, an accurate and fast operational forward model was developed for TES. The forward model is an important component of the TES retrieval model, the Earth Limb and Nadir Operational Retrieval (ELANOR), as it governs the accuracy and speed of the calculations for the retrievals. In order to achieve the necessary accuracy and computational efficiency, TES adopted the strategy of utilizing precalculated absorption coefficients generated by the line-by-line calculations provided by line-by-line radiation transfer modeling. The decision to perform the radiative transfer with the highest monochromatic accuracy attainable, rather than with an accelerated scheme that has the potential to add algorithmic forward model error, has proven to be very successful for TES retrievals. A detailed description of the TES forward model and Jacobians is described. A preliminary TES observation is provided as an example to demonstrate that the TES forward model calculations represent TES observations. Also presented is a validation example, which is part of the extensive forward model validation effort. © 2006 IEEE.Tropospheric Emission Spectrometer: Retrieval method and error analysis
IEEE Transactions on Geoscience and Remote Sensing 44:5 (2006) 1297-1306
Abstract:
We describe the approach for the estimation of the atmospheric state, e.g., temperature, water, ozone, from calibrated, spectral radiances measured from the Tropospheric Emission Spectrometer (TES) onboard the Aura spacecraft. The methodology is based on the maximum a posteriori estimate, which mathematically requires the minimization of the difference between observed spectral radiances and a nonlinear model of radiative transfer of the atmospheric state subject to the constraint that the estimated state must be consistent with an a priori probability distribution for that state. The minimization techniques employed here are based on the trust-region Levenberg-Marquardt algorithm. An analysis of the errors for this estimate include smoothing, random, spectroscopic, "cross-state," representation, and systematic errors. In addition, several metrics and diagnostics are introduced that assess the resolution, quality, and statistical significance of the retrievals. We illustrate this methodology for the retrieval of atmospheric and surface temperature, water vapor, and ozone over the Gulf of Mexico on November 3, 2004. © 2006 IEEE.Tropospheric emission spectrometer: Retrieval method and error analysis
IEEE Transactions on Geoscience and Remote Sensing 44 (2006) 1297-1307
TES atmospheric profile retrieval characterization: An orbit of simulated observations
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 44:5 (2006) 1324-1333
Retrieved' tropospheric and stratospheric BrO columns over Lauder, New Zealand
Journal of Geophysical Research D: Atmospheres 109:14 (2004)