Ripple in pixel 4A seen in alfalfa (wapp) data


    Alfa pixel 4 polA has a ripple in the bandpass with a period of 174 kHz. It was discovered while debugging the galfa spectrometer back in sep04 (see pixel4aripple sep04).

    Project a2010 (alfalfa) does 600 second  drift scans dumping once a second using 100 Mhz centered at 1385 Mhz. A single drift from 21may05 was examined and shows that the ripple is still present in pixel4a. The band passes for pixel4 with and without bandpass correction were examined to see the strength of the ripple and how stable it was over time.   The plots show the band passes and the ripple for the 600 second drift (.ps) (.pdf) :


processing: x101/050521/