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[IDV #CGA-206836]: Multiple trajectories in a single file

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  • Subject: [IDV #CGA-206836]: Multiple trajectories in a single file
  • Date: Mon, 29 Aug 2022 15:41:01 -0600
> Finally got back to this and created an example netcdf file (attached) that 
> adheres to the CF "Contiguous ragged array representation of trajectories" 
> convention 
> (https://cfconventions.org/Data/cf-conventions/cf-conventions-1.9/cf-conventions.html#_contiguous_ragged_array_representation_of_trajectories).
>   I tried opening this in version 6.1 using "netcdf/GEMPAK Point data files" 
> and "point cloud data (netcdf)" but neither appears to work (no errors but 
> nothing happens).
> 
> - Adam
> 
> 

Hi Adam,

The coordinates of your netCDF file need to be like the following:

      double time(trajectory, obs) ;
          time:standard_name = "time";
          time:long_name = "time" ;
          time:units = "days since 1970-01-01 00:00:00" ;
      float lon(trajectory, obs) ;
          lon:standard_name = "longitude";
          lon:long_name = "longitude" ;
          lon:units = "degrees_east" ;
      float lat(trajectory, obs) ;
          lat:standard_name = "latitude";
          lat:long_name = "latitude" ;
          lat:units = "degrees_north" ;

For a file with multiple trajectories, we use two dimensions: trajectory and 
obs, to define all
trajectories. Here is the document:

https://cfconventions.org/cf-conventions/cf-conventions.html#_multidimensional_array_representation_of_trajectories

Yuan

Ticket Details
===================
Ticket ID: CGA-206836
Department: Support IDV
Priority: Normal
Status: Open
===================
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