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[Support #YZT-862981]: AMV NetCDF files read in with the incorrect time in McV 1.6, but it worked in 1.5. [2405]



> Hello -
> 
> We have a few AMV (Atmospheric Motion Vector) point NetCDF files that worked 
> correctly in McV 1.5 and IDV 5.0, but don't work correctly in versions more 
> recent than those.  See the Request of this inquiry for more information as 
> well as the location of the files.  We have set Tommy J as the POC at SSEC.  
> I've run this by the NetCDF/java group and they pointed me to you to see if 
> you had any ideas on what might be happening on the IDV side.
> 
> Any thoughts?
> 
> Thanks -
> Bob Carp
> 

Bob,

Quick answer is that the latest netCDF-Java library has stricter requirement of 
the dataset to be in better CF compliance comparing to the earlier version. I 
will download a sample and find out what need to be changed.


Yuan
> ----==== Inquiry ====----
> 2405
> 
> ----==== Summary ====----
> AMV NetCDF files read in with the incorrect time in McV 1.6, but it worked in 
> 1.5.
> 
> ----==== Request ====----
> 2016-09-07 - Bob Carp
> There are currently three files in ftp://ftp.ssec.wisc.edu/pub/incoming:
> 
> amv.HIMAWARI-8.2015313.0010.ch_14.nc
> amv.Meteosat-10.2015304.1200.ch_14.nc
> amv.MTSAT-2.2014251.1114.ch_14.nc
> 
> In the IDV 5.0 and McIDAS-V 1.5, these files can all be read in as a 
> 'netCDF/GEMPAK Point Data files' data type.  When the 'Point Data' field is 
> displayed with the Point Data display type, two things happen:
> 1. The data displays with the correct timestamp
> 2. All of the vectors display in the same timestep
> 
> In any IDV/McV versions more recent than the version listed above, two things 
> happen:
> 1. The data displays with the incorrect timestamp (1969-21-31 or 1970-01-01)
> 2. All of the vectors want to display in their own timestep (you can 'fix' 
> this by adjusting the time binning of the data source)
> 
> I checked with the NetCDF/java group at Unidata and here was their response:
> As far as I can tell, toolsUI 4.3 vs 4.6 does not treats these files in the 
> same way. I know the IDV team, specifically Julien, has done some work in the 
> IDV to improve the handling of Point Data. It's possible that there is a bug 
> there, or maybe even in the way the PointFeature API from netCDF-Java is 
> being used. It also might be a limitation of the PointFeeature API, which 
> treats point data as a stream. Have you contacted the IDV group to see if 
> they are able to see what is going on with these files?
> 
> Any thoughts?  The files mentioned above should remain on ftp for a week 
> (through 9/14).  If anyone needs access to them after that date let me know 
> and I can re-post them.
> 
> 2016-08-31 - Bob Carp
> The summary of this inquiry was:
> Meteosat AMV NetCDF file reads in with the incorrect time in McV 1.6, works 
> in 1.5.
> 
> I'm changing it to:
> AMV NetCDF files read in with the incorrect time in McV 1.6, but it worked in 
> 1.5.
> 
> This is because other AMV files have the same problem, such as Himawari and 
> MTSAT.  For sample data, see /home/mcuser/inquiry-data/2417/*.
> 
> 2016-08-13 - Bob Carp
> Load the amv.Meteosat-10.2015304.1200.ch_14.nc file as a NetCDF/GEMPAK Point 
> Data Source.  Through the Properties window of the data source, change the 
> time binning to 1 hour.  This prevents having individual timesteps for each 
> data point.  Note that this is a change from 1.5, where in 1.5 you didn't 
> need to change the time binning for things to display in one tilmestep.  
> However, each point really does have its own time, so this probably isn't a 
> big deal.
> 
> The main problem is that in 1.6 the timestamp (macro and in the Time 
> Animation Widget) reads as 1969-21-31 23:58 (with time binning of 1 hr).  In 
> McV 1.5 the timestamp is read as 2015-10-31 12:00:00Z which matches the time 
> in the filename.
> 
> 
> ################################################################################
> 
> http://mcidas.ssec.wisc.edu/inquiry-v/index.php?inquiry=2405
> 
> 


Ticket Details
===================
Ticket ID: YZT-862981
Department: Support IDV
Priority: Normal
Status: Open
===================
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