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20050728: IDV - display of flow vectors from EPIC netcdf file

>From: "Charlene Sullivan" <address@hidden>
>Organization: USGS
>Keywords: 200507281346.j6SDklMr024081 IDV current profile.

Hi Charlene-

>Institution: USGS
>Package Version: Version 1.2b2
>Operating System: Windows XP
>Hardware Information: Dell Precision M20, Intel Pentim M processor 2.0 GHz, 2G
> B RAM
>Inquiry: Hello,

First of all, thanks for sending this in.  Your file uncovered a performance
bug in the latest release (as I mentioned in my other email) which will
be fixed in the 1.2 release.  You are inheriting Rich's knack for finding
these kinds of problems just before release time. ;-)

>I would like to plot current velocities from an ADCP as flow vectors.  The vel
> ocities are stored as the parameters u_1205 (Eastward velocity) and v_1206 (N
> orthward velocity) in a netcdf file (testIDVadcp3.nc attached) that follows E
> PIC conventions.  These parameters are dimensioned [time, depth, lat, lon].  
> Because the data is from a moored ADCP, lat and lon consist of one value, whi
> le depth (positive down) consists of 14 values.
>
>I have tried displaying the flow vectors by loading the netcdf file, and selec
> ting formulas -> make flow vectors from grid-relative u and v -> flow display
> s -> vector plan view.  When I do that I get an error (IDVconsole.txt attache
> d).  I have done my best to make this EPIC netcdf file more CF-compliant, but
>  I keep getting the same error.

This error is being generated because there is a valid_range attribute of 1000, 
1000
for the u and v variables.  All your data is outside this range, so the
grid ends up with missing data.  If I create the file without these
attributes, I can read in the data.  But displaying it is another problem.
The IDV currently does not support this single point type of data with
mutliple levels.  I'll see if I can tweak the code to handle a multilevel
point like this.

>Could someone please take a look at the netcdf file I provided and see if anyt
> hing sticks out as being incompatible with the IDV?  What I would really love
>  to do (someday!) for a display of this data is do a display similar to that 
> done for the NOAA Profiler Winds.  Are there any plans to add netCDF support 
> to that utility?

No, but that's a great suggestion and I'll add it to the list.  These datasets
will be a good test case for that.

>Thank-you in advance for your attention to this data.

Sorry I don't have more positive news.  I'll let you know if I come
up with an interim solution.  

Don Murray
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