29.1.9 DasFbe

Topic Version	1	Published	12/09/2016	Topic Change History
For Standard	PRODML v2.0
Type:	Group		Stereotype:	«XSDcomplexType»

This object contains the attributes of FBE processed data. This includes the FBE data unit, location of the FBE data along the fiber optical path, information about times, (optional) filter related parameters, and UUIDs of the original raw and/or spectra files from which the files were processed. Note that the actual FBE data samples and times arrays are not present in the XML files but only in the HDF5 files because of their size. The XML files only contain references to locate the corresponding HDF files containing the actual FBE samples and times.

Table 29.1.9-1 Attributes
Name	Type	Notes
FbeData	DasFbeData	A DAS array object containing the FBE DAS data.
FbeDataTime	DasTimeArray	A DAS array object containing the sample times corresponding to a single ‘scan’ of the fiber. In a single ‘scan’, the DAS measurement system acquires raw data samples for all the loci specified by StartLocusIndex and NumberOfLoci. The ‘scan’ frequency is equal to the DAS acquisition pulse rate.
FbeDataUnit	String64	Data unit for the FBE data.
FbeDescription	String2000	Description of the FBE data.
FbeIndex	NonNegativeLong	The nth count of this Fbe instance in the Acquisition. Recommended if there is more than 1 Fbe instance in this Acquisition. This index corresponds to the Fbe array number in the H5 file.
FilterType	String64	A string describing the type of filter applied by the vendor. Important frequency type filter classes are: frequency response filters (low-pass, high-pass, band-pass, notch filters) and butterworth, chebyshev and bessel filters. The filter type and characteristics applied to the acquired or processed data is important information for end-user applications.
NumberOfLoci	NonNegativeLong	The total number of ‘loci’ (acoustic sample points) acquired by the measurement instrument in a single ‘scan’ of the fiber.
OutputDataRate	FrequencyMeasure	The rate at which the FBE data is provided for all ‘loci’ (spatial samples). This is typically equal to the interrogation rate/pulse rate of the DAS measurement system or an integer fraction thereof. Note this attribute is mandatory for FBE and spectrum data. For raw data this attribute is optional.
RawReference	UuidString	A universally unique identifier (UUID) for the HDF file containing the raw data.
SpatialSamplingInterval	LengthMeasure	The separation between two consecutive ‘spatial sample’ points on the fiber at which the signal is measured. It should not be confused with ‘spatial resolution’. If this data element is present in the DASFbe object, then it overwrites the SpatialSamplingInterval value described in DASAcquistion.
SpatialSamplingIntervalUnit	String64	Only required in Hdf5 file to record the unit of measure of the sampling interval of the Fbe.
SpectraReference	UuidString	A universally unique identifier (UUID) for the HDF file containing the spectra data.
StartLocusIndex	NonNegativeLong	The first ‘locus’ acquired by the interrogator unit, where ‘Locus Index 0’ is the acoustic sample point at the connector of the measurement instrument.
TransformSize	NonNegativeLong	The number of samples used in the TransformType.
TransformType	String64	A string describing the type of mathematical transformation applied by the vendor. Typically this is some type of discrete fast Fourier transform (often abbreviated as DFT, DFFT or FFT).
uuid	UuidString	A universally unique identifier (UUID) of an instance of FBE DAS data.
WindowFunction	String64	The window function applied to the sample window used to calculate the frequency band. Example 'HANNING', 'HAMMING', 'BESSEL' window.
WindowOverlap	NonNegativeLong	The number of sample overlaps between consecutive filter windows applied.
WindowSize	NonNegativeLong	The number of samples in the filter window applied.

Table 29.1.9-2 Associations
Association	Notes
From: DasFbe.Custom 0..1To: DasCustom Association
From: DasProcessed.Fbe 0..*To: DasFbe Association