Visibility-Based Demodulation of Rhessi Light Curves

The Reuven Ramaty High Energy Spectroscopic Solar Imager (RHESSI) uses the rotational modulation principle to observe temporally, spatially, and spectrally resolved hard X ray and gamma ray images of solar flares. In order to track the flare evolution on time scales that are commensurate with modulation, the observed count rates must be demodulated at the expense of spatial information. The present paper describes improvements of an earlier demodulation algorithm, which decomposes the observed light curves into intrinsic source variability and instrumental modulation.