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[netCDFJava #LEC-363579]: Get data through lat lon coordinates



Greetings,

Yes, the coordinate system information is constructed based
on the X/Y variables and the projection information contained
in the _HDFEOS_CRS variable, so it's 'virtual', so to say, in
that the lat/lon does not actually live in the file, but only
in memory.

The netcdf-ikvm library was not developed by Unidata, and the
project github page is no longer available. I downloaded the
nupkg file and explored its contents, but I cannot tell which
version of netCDF-Java was used by the project. Given the date
on the project, I'm guess it was version 4.2. We are currently
on version 4.6.12, and Panoply is using a beta version of 5.0.
I was able to grab the old 4.2 code of netCDF-Java, and it is
unable to do the coordinate system construction for the modis
dataset, and cannot be read by the GridDataset class, which would
explain why you get a null when trying to access a grid. You
could possibly reach out to the developer of netcdf-ikvm to see
if he would be willing to update the netCDF-Java version used
in his project (https://github.com/gena).

Cheers,

Sean

> Hi
> Thank you for tracking.
> I developed several windows software to extract data from netcdf files for
> non-programmer users. https://agrimetsoft.com/netcdf.aspx
> All tools have been developed in c# and now I want to develop a modis data
> extractor so I used this library(https://www.nuget.org/packages/netcdf-ikvm/)
> in C#
> 
> But when I open the HDF file in C# it is different than other files(netcdf
> files). These files have not Lat/Lon or XDim/YDim but the name of the
> dimension of variables is XDim/YDim. If I have these variables my problem
> will solve. I open these files by Panoply and it show the XDim/YDim but it
> write bellow text for it:
> 
> *********************************************************************
> 
> *Showing enhanced mode description.*
> Variable appears to be 'virtual', constructed based on dataset metadata.
> 
> **********************************************************************
> 
> I will be so pleased for helping me In finding a way to read dimension
> variables.
> [image: image.png]
> 
> 


Ticket Details
===================
Ticket ID: LEC-363579
Department: Support netCDF Java
Priority: Urgent
Status: Open
===================
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