The following lists contains active research questions in my personal research and that of my group members.

• Multiscale Data Assimilation - with Aamir Nadeem [PHD]

• Model Approximations and Model Diagnostics in Data Assimilation Cycles - with Babatunde Odunuga [PHD]

• Mathematica Analysis of Multistep Data Assimilation - with Perianez, Reich, Schraff, Rhodin

• Assimilating Satellite Cloud Product in an Ensemble Data Assimilation for NWP - with Schomburg and Schraff

• <hi>Orthogonality Sampling/ Direct Sampling and inverting the Bessel Volume Potential - RP</hi>

^{Original and reconstruction from a far field pattern of uniform sources located in the rectangle, here using 7 different frequencies (left), using four frequencies between wavenumber 1.5 and 2.5, one incident field only (right). This is work in progress.}

• GPS Slant Delay Operator - with Michael Bender et al.

• GPS Tomography Algorithms - with Michael Bender et al

• Particle Filter for Large Scale Problems in NWP - with Schraff, Rhodin, Reich

• SEVIRI infrared radiance assimilation for convective models - with Otkin, Perianez et al.

• Mathematical Analysis for Ensemble Kalman Filter Convergence Questions - with Perianez et al. [PHD]

• Data Assimilation in Neural Field and Neural Mass Models - with Ingo Bojak

• Radar data assimilation in convective models - with Theresa Bick et al.

^{Radar Data Assimilation based on an Ensemble Kalman Filter in a Convection Permitting Model with Rapid Update Cycle. We show the influence on the cycling frequency on the fractional skill score. Here, for the 4d-Version of the LETKF, lower update rates lead to better fractional skill skores after one hour of forecast.(left) Further, we compare latent heat nudging with full Volume Radar assimilation - they were of comparable quality in these experiments. The experiments have been carried out by Bick et al.}

• Kilometer Scale Ensemble Data Assimilation (KENDA) - with Schraff, Reich, Rhodin et al. [under review]

• Diagnostics for Ensemble Data Assimilation Systems - with Dora Föhring, Rhodin and Köpken-Watts

• Wind Power Assimilation OSSE - with Stefan Declair, Annika Schomburg et al.

• Ensemble Data Assimilation for the ICON Model (IEDA) - with Ana Fernandez et al.

• Inverse Problems for Delay Neural Field Equations - with Jehan Alswailhi [PHD]

• Ensemble Methods for Inverse Scattering Problems - with Quaz Muhammad Zaigham Zia

• Photovoltaic Measurement Assimilation for Energy Applications - with Annika Schomburg et al.

• <hi>Data Assimilation for Cognitive Structures</hi> - RP

^{ICON Global data assimilation model grid with NEST over Europe.}