The figure below shows monthly noise spectra for different channels recorded at an IDA station. Each noise spectrum is calculated from all the data available for a particular month. The background noise level is defined as the signal level not exceeded 10% of the time.
Channel names follow the SEED convention. The location code "-XX" indicates that the data have not been repaired to correct the flaw in the Digital Signal Processing (DSP) Unit of the IDA Mark 7 data logger. The location code "-00" indicates that the data have been repaired. No location code indicates data that have not been repaired. The spectra and the station/channels are color-coded.