Extensive air shower detection with CROME in the L band

Extensive air showers are detected via particle measurements on the ground, the energy deposition in the atmosphere or via MHz radio waves produced mainly by charged particles moving in the magnetic field of the Earth. In addition, emission in the GHz-range is predicted due to molecular bremsstrahlung. The Cosmic-Ray Observation via Microwave Emission (CROME) setup at the Karlsruhe Institute of Technology consists of several antennas in the L band, the C band and the Ku band. The KASCADE-Grande detector, which triggers the CROME experiment externally, provides calibrated measurements of air showers at the same location. We present the setup of an L-band antenna, the signal chain including the data acquisition, and the first results of a possible event candidate. To determine the environmental background noise we show long-term background measurements revealing temporary monofrequency emitting interference which can be removed offline in the data-analysis process.