On 5/17/11 8:46 AM, Benno Blumenthal wrote:
> I have a trajectory dataset
I think a clarification is needed here: What is a "trajectory" in this use?
I've seen it used for measured locations of various drifters, and also
for the path of particles or whatever, as predicted by a model. If the
later, then I can see why the forecast_* names may make sense.
> is pretty much on the mark: I was using the word "period" because the
> standard_name's grammar suggests using period for a time interval and
> saving "time" for temporal with reference time, though "elapsed_period"
> sounds a bit strange to my ears.
What exactly are you trying to express for "period" in this case?
> As for my using "forecast_reference_time", I am willing to accept the
> judgment that it is not what I want, but I can't say that it is all
> that clear.
frankly, it's not clear to me either, but I'd like to know what it means
-- I work with others' forecasts a fair bit.
I interpret it as the time the initial conditions, etc. were collected
-- that would often be the time the computation started -- so it would
be one time, not a sequence. (for one forecast run, anyway)
Is that at all right?
> Forecasts are integrations from initial conditions a.k.a
> the analysis, which is precisely what happens in a trajectory --
so in this case, you are referring to a modeled (or forecasted)
trajectory? In which case, yes, it seems the start time for that could
be the "forecast_reference_time".
-Chris
--
Christopher Barker, Ph.D.
Oceanographer
Emergency Response Division
NOAA/NOS/OR&R (206) 526-6959 voice
7600 Sand Point Way NE (206) 526-6329 fax
Seattle, WA 98115 (206) 526-6317 main reception
Chris.Barker at noaa.gov
Received on Tue May 17 2011 - 13:42:53 BST
