Thursday

A new two-stage method has been developed that greatly increases the computational efficiency of estimating DEMs from multi-channel EUV image data. The first stage can process a thousand DEMs per second on a standard desktop computer, and is simple in concept and implementation. The resulting DEMs are smooth, positive, and shown to replicate model DEMs reliably when tested on synthetic data. The second stage is a data gridding method, based on the realisation that many regions within EUV data of the low solar corona share similar measurement values, and thus give similar DEMs. Once a database of DEMs has been created, the gridding method allows millions of DEMs (i.e. a full-resolution AIA image set) to be produced in a few seconds. Whilst packaged as a two-stage method, the gridding method is in principle compatible with any other DEM-estimating routine. Given the large amount of data produced by AIA/SDO, and consideration of future observations such as EUI and SPICE onboard Solar Orbiter, this new method is timely, and will enable large-scale studies of the evolution of DEMs in different solar regions over time.