A spectrometric measuring head for harvesting machines and other agricultural equipment comprises a housing with a window, in which a light source, a spectrometer arrangement and at least two standards for internal recalibration are provided. The body portion includes an upper portion and a base portion and defines an interior space. The second OFDM symbol is adjacent to the first OFDM symbol, and the center subcarriers are part of a system bandwidth and a part of the center subcarriers is not used for mapping the secondary synchronization sequence.