Digital Beam Position Measurement at GSI-SIS and CERN-PS

New digital BPM techniques needed in hadron machines, accelerating beams with fast varying frequencies, are to be presented. The role of analog electronics is reduced to signal amplification only. This paper explores approaches for the evaluation of acquired digital signals, suggesting systems for "free running" estimation as well as machine timing dependent methods. For the integration window estimation, two filtering methods will be introduced, me-dian and FFT filtering, both methods detecting peaks at bunch signal starting and ending points. Parallel to those a digital PLL approach is tested. This project is part of an EU-RP6 design study, collaborating members being CERN-AB, GSI-SD, I-Tech, FZ Jülich and TUD.