Blacknest BDS Notes
Note that this is a "work in progress" document and is being continually updated.
Introduction
This document provides a list of notes, with possible answers. There is
up-to-date information on the BEAM BDS support website at: https://portal.beam.ltd.uk/support/blacknest/info
System Notes
- How to select when there is data overlap ? If TapeDigitiser
it would be best to select the later data file. Curently the
system returns a set of data segments within the time frame requested.
It is up to the user to decide which data segment is required.
- If a set of channels is required in synchronously sampled
form for BKNA or other such sample multiplexed formats, then the system
requires the channels to be stored within a single data file and marked
as synchronous. We could
add the ability to re-sample to the highest sample rate if required,
with appropriate
warning so that any set of data channels could be returned in sample
multiplexed formats.
- If there are data holes within a segment of data then these
will be passed to the user. If they have requested the data in a
particular format then an error message will be returned. We could add
the ability to breakup the data segments based on the data holes. Data
formats, such as IMS, would then return ethe multiple segments of data.
- What happens when MetaData changes with the time period ? At the moment we use the MetaData from the start time requested.
- Station locations have array offsets in them. Should we move these to the ArrayChannels table ?
- Need to add support for leap seconds. Probably best to have a
flag in each data block which is set if a leap second change occurred
within the block. The number of samples would not match the time stamp
period by 1.
- We could perform an Import check for Metadata for the entire time range on import.
General Notes
- All Station Codes in the world should be unique and registered
with the ISC in the United Kingdom/the National Earthquake Information
Center (NEIC) in the United States ?
- Channel code standards are defined in the IMS "Formats and
Protocols for Messages" document. Also in the SEED manual. Are all
codes to these rules ?
- There are some Instrument type codes defined in the SEED manual (Appendix A). Are all codes to these rules ?