Thread: Question Regarding data availability

Started: 2018-09-20 19:16:52
Last activity: 2018-09-20 19:16:52
sampath
2018-09-20 19:16:52
Hi,

When I check some stations availability in IRIS DMC (any region), I saw
some stations are operated before 2000. However, I saw on the bottom of
the each station info page showing "query archive for data day
availability" are some times later. For example if station start to
operate in 2000, and station info page is shown data available after 
2010. Is this mean I can't get data between 2000-2010? Thank you.

Sampath

  • Nick Falco
    2018-09-20 17:20:56
    Hi Sampath,

    Network, station, and channel epochs don’t represent data availability, but rather whatever timespan that a network was assigned to. In other words, just because a networks metadata was entered with a epoch from 2000-2010, doesn’t necessarily mean that there is time series data for this entire period of time.

    For example, a temporary experiment that may have recorded data for only one month, could have a network epoch for an entire year since that was the time that their assigned FDSN network code was valid. It is however considered best practice for network operators to trim epochs in their metadata to closely match the times that data was actually being recorded, but you shouldn’t count on this when determining data availability.

    I suggest using the irisws-availability https://service.iris.edu/irisws/availability/1/ web service for searching for actual waveform data availability. Below is an example query that returns a list of time spans for which there is waveform data in the archive:

    http://service.iris.edu/irisws/availability/1/query?network=IU&station=ANMO&channel=BHZ&start=2000-01-01T00:00:00&end=2010-12-31T00:00:00&mergequality=false

    A web service url builder is available at https://service.iris.edu/irisws/availability/docs/1/builder/. Just enter your network/station/location/channel of interest into the form, and a URL will be produced for you at the bottom of the form.

    I should mention that there is a new MetaData Aggregator (MDA)  http://ds.iris.edu/mda program that is going to be released in the near future. Once the new program is released, it will provide links to the availability web service which will make it easier to view data availability information.

    Please let me know if you have any more questions, or want me to explain anything in greater detail.

    Thanks,

    Nick
    --
    Nick Falco
    Web & Apps Developer
    IRIS Data Management Center
    nick<at>iris.washington.edu

    On Sep 20, 2018, at 9:31 AM, sampath <srathnayakam<at>geo.umass.edu> wrote:

    Hi,

    When I check some stations availability in IRIS DMC (any region), I saw
    some stations are operated before 2000. However, I saw on the bottom of
    the each station info page showing "query archive for data day
    availability" are some times later. For example if station start to
    operate in 2000, and station info page is shown data available after
    2010. Is this mean I can't get data between 2000-2010? Thank you.

    Sampath

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