Re: update on trajectory support in idv?

Hi Nick-

Nick Bower wrote:
We currently support trajectories with a vertical dimension of
Altitude, but it looks like yours is pressure.  Do you have
an Altitude variable in your file?

Ah no. Why do I need that - I was hoping to use IDV for cyclone tracking (ie no altitude applicable). I should have mentioned a 2D trajectory perhaps? The 3+ dimensions are physical and measured parameters, not part of the location information - more part of.

Okay, thanks for the clarification.  Our data model for a
track has always been on of lat/lon/alt.  We'll look into
this use case.

You also need to select the Data Source Type in the chooser
as a Track File instead of using the default (I'm Feeling Lucky).
For .nc files, the default tries to open it as a grid.

Yes as soon as I selected "track", my .nc file disappears. Stuart W has kindly pointed out that I need to rename the file * for it to show up as a track. It then does (which doesn't seem an obvious feature to me at all - faq entry??), but I get an exception;

It shouldn't disappear.  You should end up with the same error
as below.

As for Stu's suggestion, the IDV uses file patterns to determine
the type of Data Source factory it should use when you use
the "I'm Feeling Lucky" option.  It just so happens that
is one of the patterns it uses for tracks (this pattern
comes from P3 aircraft tracks). Could not open trajectory file:C:\Documents and Settings\nick\Desktop\
at at

Looking at the code, it seems like perhaps I'm barking up the wrong tree with trajectories, as all but one assume altitude (ie 3D, eg soundings). Perhaps what I'm after is not a trajectory? I'm just after a 2D cyclone track really.

Again, this is because or our mental model of a track at
the current time, which seems flawed in this case.

Could you provide a sample file?  Send it to

Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307