Clarification on description

[andreas-wuestefeld]

Reading the meta-data descriptions several points come up, and need perhaps clarification:

• Overview:

  • Start/End Date: Why is that limited to yyyy-mm-dd and not full yyyy-mm-ddTHH:MM:SS

• Cable

  • CableCoordinates: This is redundant with the "Channel XYZ" coordinates. It should be unique where such information is stored to avoid confusion. Here it also not specified how the coordinates should be sorted (XYZ, YXZ, Lat/Long,....)
  • Connector_Coordinates: Maybe Channel Number is an easier and more unique descriptor?
  • Fibre_Mode: Perhaps a boolean is better? : Is_Single_Mode
  • Refraction_Index: I am not a native speaker, but "refractive index" sounds more correct to me :-)
  • Fibre Geometry is redundant with "winding angle"
  • Winding angle: Clarify that 0 deg equals a straight cable
  • Fiber start location: It says that it should be a float, but I guess you mean a list of floats? what coordinate system?
  • Comments: I like to have this field available! Should perhaps be available for a main sections?

• Acquisition

  • SamplingRate: Should that be stored sampling rate?
  • InterrogatorRate: Maybe more specific would be InterrogationRate?
  • PRR: I wonder if there is any useful application to keep InterrogationRate and PRR
  • PulseWidth: This may be not applicable for chirp-pulse interrogators (like ASN) Perhaps worthwhile to check with them
  • GaugeLength: It says "between a pair of PULSES", but it should be "pair of CHANNELS" right?
  • ChannelSpacing: Some interrogators allow storing of spatially downsampled data. If this meta data is storing all possible information from the interrogator, then this should be stored here as well. But I feel the native units should be rather stored in the interrogator field, to avoid confusion
  • Decimation: Clarify if this is spatial or temporal (Redundant anyway with native/stored sampling Rate)
  • TimeFilter: Nice to have this as a separate field, but a more general "Applied_Pre-Processing" field may be better?

• Channel

  • Clarify if this should be a list of objects or a single object with lists (I prefer the latter)
  • Distance along fiber: Clarify if this is optical, cable, or geodetic distance (optical should perhaps be covered in the fibre/cable section? Geodetic distance is redundant if coordinates are given)
  • Elevation: perhaps be consistent and call this Z-Coordinate?
  • Depth: To avoid confusion I strongly suggest to only allow one Z-coordinate direction. Since this is for IRIS, I suggest to stick to that system with positive up!
  • Strike/Dip: This is redundant information and can be obtained programatically from the coordinates
  • Direction of Pulse: Is there any case where this is not increasing? It says it is in units of degrees, that needs more clarification

[chad-earthscope]

This issue continued at FDSN/DAS-metadata#7