AN INTERPOLATION/EXTRAPOLATION APPROACH TO X-RAY IMAGING OF SOLAR FLARES

作者：Allavena Silvia^*; Piana Michele; Benvenuto Federico; Massone Anna Maria

来源：Inverse Problems and Imaging, 2012, 6(2): 147-162.

DOI：10.3934/ipi.2012.6.147

• X-ray solar imaging
• Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI)
• visibilities
• iterative regularization methods
• soft thresholding

We describe aninterpolation/extrapolation procedure that reconstructs X-ray maps of solar flares using as input data sparse samples of the Fourier transform of the radiation flux, named visibilities. The algorithm is based on two steps: in the first step the performance of an interpolation routine is optimized by representing the visibilities according to favorable coordinates in the frequency plane. In the second step two extrapolation schemes are introduced, respectively based on the projection and the thresholding of the Landweber iterative method. The procedure is validated against realistic synthetic visibilities and applied to experimental measurements provided by the NASA satellite Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI).

• 出版日期2012-5