• A. Kosicek, T. Karčnik, V. Poucki
  I-Tech, Solkan
• K.B. Scheidt
  ESRF, Grenoble

Libera, the beam position processor, features the so-called Turn-by-Turn (TbT) data output, the data rate being exactly the revolution frequency of the accelerator. This data is essential for commissioning of the accelerator as well as for various machine physics studies. However, due to the "natural" properties of correctly structured filters (respecting the Nyquist theorem), the smearing between adjacent TbT samples is not negligible. The purpose of the modified DDC filter is to remove smearing between adjacent TbT samples, especially with partial fill patterns. The usage of Modified DDC filters gives the best results for the studies using the Turn-by-Turn measurements, with the benefit of "true & pure" Turn-by-Turn results (no smearing). The method, its implementation and first results are discussed in this paper.