Amplitude Check

Investigate daily average (noise) amplitudes at a given frequency for every data channel. The daily average is corrected (levelled) by the median of average values of all stations. These levelled daily average values stay normally within a certain range. Unusual deviations of this value detected in a long term statistics indicate problems with data or metadata. The following table shows automatically detected deviations for three channels (ZNE or Z12), if existing, in color codes: green - OK, yellow - the last day shows unusual deviation, orange - the last week shows unusual deviation, red - the last month shows unusual deviation, gray or white - no (recent) data. The station set is separated in broadband stations (VBB) and short period (SP) stations, investigated at different frequencies. VBB stations show low scatter in the noise data at 0.15 Hz since the signal is dominated by the ocean microseism. For SP stations this frequency is out of scale. Therefore a higher frequency is chosen where the scatter is much larger and the resolution for detecting errors is reduced.

The figures below the table show the individual measurements on the channels. Description see there.

This page is daily updated.

last 365 days, created 15-May-2021

VBB Stations @ 0.15Hz
GR.AHRW GR.ASSE GR.BFO GR.BRG
GR.BSEG GR.BUG GR.CLL GR.CLZ
GR.FBRG GR.FUR GR.GEC2 GR.GEC7
GR.GOLD GR.GOR1 GR.GRA1 GR.GRA2
GR.GRA3 GR.GRA4 GR.GRB1 GR.GRB2
GR.GRB3 GR.GRB4 GR.GRB5 GR.GRC1
GR.GRC2 GR.GRC3 GR.GRC4 GR.GTTG
GR.HAM4 GR.HLGA1 GR.HLGA3 GR.HLGB1
GR.HLGB2 GR.IGAD GR.KAST GR.KHUS
GR.KUDEN GR.LNIZ GR.LUEB GR.MILB
GR.MOX GR.RETH GR.RETHO GR.SKMB
GR.TNS GR.UBR GR.WET GR.ZARR
SX.NEUB SX.TANN SX.WIMM TH.ABG1
TH.ANNA TH.BBWF TH.BONN TH.CHRS
TH.CRUX TH.FRAU TH.GEIDO TH.GRZ1
TH.HKWD TH.HWTS TH.LEIB1 TH.MEHR
TH.MLFH TH.MOB2 TH.MODW TH.MORAS
TH.NEUST TH.PLN TH.POSS TH.RANIS
TH.SONN TH.SPAHL TH.ZEITZ TH.ZEU

SP Stations @ 1.00Hz
GR.A807 GR.DEEL GR.FAHL GR.GEA0
GR.GEA1 GR.GEA2 GR.GEA3 GR.GEB1
GR.GEB2 GR.GEB3 GR.GEB4 GR.GEB5
GR.GEC1 GR.GEC3 GR.GEC4 GR.GEC5
GR.GEC6 GR.GED1 GR.GED2 GR.GED3
GR.GED4 GR.GED5 GR.GED6 GR.GED7
GR.GED8 GR.GED9 GR.INS1 GR.INS3
GR.INS4B GR.INS5 GR.INS6B GR.INS7
GR.INS8 GR.INSH GR.RAST GR.SEVE
GR.SYKE GR.TMO20 GR.TMO22 GR.TMO54
GR.TMO55 GR.TMO57 GR.TMO66 GR.UNDO
RN.BAVN RN.BKLB RN.BTEZ RN.BULI
RN.HMES RN.IBBE RN.IBBS RN.ZER1
RN.ZERL SX.FBE SX.GUNZ SX.MULD
SX.SCHF SX.TRIB SX.WERD SX.WERN

Colors: no data amplitude ok last day over thresh last week over thresh last month over thresh


The figures below show the levelled average of the last 365 days (x-axis: 0 = one year ago, 364 = yesterday) in color codes, scaled by the individual standard deviation of the measurement series. Bold colors in red and blue indicate large deviations from the average to high or low values, respectively. Gray or pastel shaded colors represent the normal scatter. White means no data computed. The numbers after 'm:' and 's:' in the figure titles are the relative mean and the standard deviation in log10(nm/s), respectively. Please note that the mean and standard deviation is computed after removing the upper and lower 15% of the data to remove the influence of outliers. Maximum color boldness is reached at 10 standard deviations (red for positive, blue for negative amplitudes). The color intensity for log amplitudes below 5.5 standard deviations is reduced by a square function. Similar color patterns at neighbored stations indicate natural undulations in the noise signal.

Color coded deviations VBB

relative amplitudes VBB


Color coded deviations SP

relative amplitudes SP