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.

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.HLGA2			GR.HLGA3
	GR.HLGB1			GR.HLGB2			GR.IGAD			GR.KAST
	GR.KBON			GR.KHUS			GR.KUDEN			GR.LNIZ
	GR.LUEB			GR.MILB			GR.MOX			GR.RETH
	GR.RETHO			GR.SCHI			GR.SKMB			GR.TNS
	GR.UBBA			GR.UBR			GR.WET			GR.ZARR
	HS.RIED			HS.WBA			KQ.BIRK			KQ.MRLW
	KQ.NONN			KQ.PEEM			SX.BURZL			SX.FROHN
	SX.NEUB			SX.TANN			SX.WIMM			TH.ABG1
	TH.ANNA			TH.BBWF			TH.BONN			TH.CHRS
	TH.CRUX			TH.FRAU			TH.GEIDO			TH.GERA
	TH.GLEI			TH.GRZ1			TH.HKWD			TH.HWTS
	TH.KAMM			TH.LEIB1			TH.MEHR			TH.MLFH
	TH.MODW			TH.MORAS			TH.NEUST			TH.PLN
	TH.POSS			TH.RANIS			TH.SONN			TH.SPAHL
	TH.THWA			TH.VITZ			TH.WARTH			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.GOR3			GR.GOR6
	GR.HALO			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			GR.ZURM			HS.EBSD
	HS.GODD			HS.GWBC			HS.GWBD			HS.GWBE
	HS.GWBF			HS.GWBO			HS.WBB			HS.WBBU
	HS.WBED			HS.WBFO			HS.WBG			HS.WBNH
	HS.WBRD			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.ROHR			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

Color coded deviations SP