Primary Particle Energy Calibration of the EAS Radio Pulse Height

LOPES is the pioneering experiment for the measurement of ra dio emission from air showers with digital radio receivers. It is set up at the site of the KA SCADE-Grande air shower array and takes data in conjunction with it. This gives the unique possibili ty to combine LOPES and KASCADE-Grande data. In the first phase LOPES consisted of 10 antennas placed inside the KASCADE array. In its second phase it has been extended to 30 antennas, which increases th e detection rate of well reconstructed events. Also a new, absolute calibration of the radio antennas is now available. By correlating the measured radio pulse height with air shower parameters measured by KASCADE -Grande, we have derived a formula that describes the radio pulse height as a function of air shower g eometry and primary particle energy. Thus allowing us to estimate the cosmic ray energy from radio data .