Re: FDSNWS starttime/endtime
Philip Crotwell
in internally is:
"""
starttime: Required
Limit to metadata epochs ending
after the specified start time.
"""
Philip
On Tue, Jul 28, 2015 at 6:02 AM, Tobias Megies <
meg...@geophysik.uni-muenchen.de> wrote:
> Hi all,
>
> during implementing fdsnws-station in a local database system, we
> stumbled over some inconsistencies in the specifications of the behavior
> for parameters "starttime" and "endtime".
>
> The official specs state:
>
> Table 4. Parameter descriptions for the fdsnws-station service.
>
> """
> starttime Required
> Limit to metadata epochs starting on or
> after the specified start time.
> """
>
> So, basically that would mean that a channel epoch starting before the
> set "starttime", but recording data all the way through "starttime" and
> later is supposed to not be included, because the epoch does not start
> "on or after the specified time" but rather before it.
>
> I think this is in collision with the intuitive interpretation of
> "starttime" restriction in the search and it is also in collision with
> the more general specification of time parameters on page 6:
>
> """
> Time parameter interpretation
>
> The starttime parameter should be interpreted as selecting any data or
> information (time series samples, earthquake origins, metadata epochs)
> at times on or later than the value specified.
> Similarly, the endtime selects any data or information at times on or
> prior to the value specified.
> The selection shall include any metadata epochs
> intersecting with the specified time range.
> """
>
> Looking at real world implementations, e.g. at IRIS, the "starttime"
> parameter is defined as one would expect intuitively and by reading the
> general "time parameter interpretation":
>
> """
> start[time]
> Limit to metadata describing channels operating on or
> after the specified start time.
> """
>
>
> I suggest that the wording in the official FDSNWS specs should be
> changed, probably to something like (endtime accordingly):
>
> """
> starttime: Required
> Limit to metadata epochs active on or
> after the specified start time.
> """
>
>
> best,
> Tobias
>
>
>
>
> --
> Dipl.-Geophys. Tobias Megies
>
> Geophysikalisches Observatorium
> Ludwigshöhe 8
> 82256 Fürstenfeldbruck
>
> Ludwig-Maximilians-Universität
> Department für Geo- und Umweltwissenschaften
> Sektion Geophysik
> Theresienstrasse 41/IV
> 80333 München
>
> Tel: +49 (0) 89 2180-73981
> +49 (0) 89 2180-4326
> Mail: tobias...@geophysik.uni-muenchen.de
>
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