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    <p>Hi Rich,</p>
    <p>This sounds like just the right solution.  It's onsistent with
      the use of <tt>precise_lon </tt>and <tt>precise_lat </tt>in <tt>Example
        H.5. (A single timeseries with time-varying deviations from a
        nominal point spatial location)</tt></p>
    <p>It's a pretty complicated encoding, though.  To make sure that
      you get interoperability out of using it, it's important that
      other folks generating/analyzing similar data do things the same
      way.  (NOAA/PMEL scientists are generating quite a lot of
      wire-crawler data, for example.)  So it seems like a good idea to
      write this up as a special encoding example that, like H.5., gets
      explicitly documented in the next CF version.<br>
    </p>
        - Steve<br>
    <br>
    ==================================================<br>
    <br>
    <div class="moz-cite-prefix">On 2/28/2017 11:18 AM, Signell, Richard
      wrote:<br>
    </div>
    <blockquote
cite="mid:CAFhraUzpHxYWN=BNpOUskeNwvpiB7yJ469niScPRe0rZ+wkMww@mail.gmail.com"
      type="cite">
      <div dir="ltr">CF Folks,
        <div><br>
          <div>Okay, with help from the ERDDAP community</div>
          <div><a moz-do-not-send="true"
              href="https://groups.google.com/forum/#%21topic/erddap/xfAufA8Qyhg">https://groups.google.com/forum/#!topic/erddap/xfAufA8Qyhg</a></div>
          <div>I think I figured this out:</div>
          <div><br>
          </div>
          <div>The solution would be to use nominal "time(profiles)" and
            "precise_time(obs)".   So we would write something like<br>
            <br>
            <a moz-do-not-send="true"
href="https://data.ioos.us/gliders//thredds/dodsC/deployments/rutgers/unit_191-20150105T1443/unit_191-20150105T1443.nc3.nc.html"
              target="_blank">https://data.ioos.us/gliders//<wbr>thredds/dodsC/deployments/<wbr>rutgers/unit_191-<wbr>20150105T1443/unit_191-<wbr>20150105T1443.nc3.nc.html</a><br>
            <br>
            with both "time" and "precise_time", but instead of using
            the multidimensional representation, use the ragged
            representation, like this<br>
            <br>
            <a moz-do-not-send="true"
href="http://cfconventions.org/cf-conventions/cf-conventions.html#_ragged_array_representation_of_time_series_profiles"
              target="_blank">http://cfconventions.org/cf-<wbr>conventions/cf-conventions.<wbr>html#_ragged_array_<wbr>representation_of_time_series_<wbr>profiles</a><br>
            <div class="gmail_extra"><br>
            </div>
            <div class="gmail_extra">So in addition to
              "precise_time(obs)" we would also have data variables like
              "temperature(obs)". </div>
            <div class="gmail_extra"><br>
            </div>
            <div class="gmail_extra">Thanks,</div>
            <div class="gmail_extra">Rich</div>
            <div class="gmail_extra"><br>
            </div>
            <div class="gmail_extra">
              <div class="gmail_quote">On Tue, Feb 28, 2017 at 7:27 AM,
                Signell, Richard <span dir="ltr"><<a
                    moz-do-not-send="true"
                    href="mailto:rsignell@usgs.gov" target="_blank">rsignell@usgs.gov</a>></span>
                wrote:<br>
                <blockquote class="gmail_quote" style="margin:0px 0px
                  0px 0.8ex;border-left:1px solid
                  rgb(204,204,204);padding-left:1ex">CF Folks,<br>
                  <br>
                  What would be the best DSG featureType to represent a
                  wire-crawling<br>
                  sensor that has a fixed lon,lat location, but
                  non-uniform depth<br>
                  interval as it goes up and down, and takes enough time
                  that the<br>
                  profile might not be accurately represented with a
                  single time value?<br>
                  <br>
                  On this ERDDAP site the featureType is "trajectory":<br>
                  <a moz-do-not-send="true"
href="http://ooi-data.marine.rutgers.edu/erddap/info/CP04OSPM-WFP01-04-FLORTK000-flort_kn_stc_imodem_instrument-telemetered-d0005/index.html"
                    rel="noreferrer" target="_blank">http://ooi-data.marine.<wbr>rutgers.edu/erddap/info/<wbr>CP04OSPM-WFP01-04-FLORTK000-<wbr>flort_kn_stc_imodem_<wbr>instrument-telemetered-d0005/<wbr>index.html</a><br>
                  <br>
                  and I'm wondering if that's the best, or whether
                  "timeSeriesProfile"<br>
                  would be better, written as as ragged array with
                  profile_index?<br>
                  <br>
                  Certainly if we assigned a "nominal time" for each
                  cast, then it would<br>
                  clearly be representable as timeSeriesProfile, but
                  it's not clear to<br>
                  me that it meets the CF conventions if time varies
                  within the cast.<br>
                  <br>
                  There would be value in allowing the time-varying
                  values within the<br>
                  profile, but also labeling/indexing the profiles,  so
                  that people<br>
                  could easily extract, say, all the "down" profiles,
                  excluding the "up"<br>
                  (or vice versa).<br>
                  <br>
                  Thanks,<br>
                  Rich<br>
                  <span class="gmail-HOEnZb"><font color="#888888"><br>
                      --<br>
                      Dr. Richard P. Signell   (508) 457-2229<br>
                      USGS, 384 Woods Hole Rd.<br>
                      Woods Hole, MA 02543-1598<br>
                    </font></span></blockquote>
              </div>
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              <br clear="all">
              <div><br>
              </div>
              -- <br>
              <div class="gmail_signature">Dr. Richard P. Signell  
                (508) 457-2229<br>
                USGS, 384 Woods Hole Rd.  <br>
                Woods Hole, MA 02543-1598</div>
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