Re: [Fwd: IDV - NetCDF format for xyz data grid mapping to transverse Mercator]

• To: Stuart Wier <wier@xxxxxxxxxx>
• Subject: Re: [Fwd: IDV - NetCDF format for xyz data grid mapping to transverse Mercator]
• From: John Caron <caron@xxxxxxxxxxxxxxxx>
• Date: Thu, 22 Dec 2005 15:18:52 -0700

Hi Stu:

Its not correctly assigning the coordinate transform.
Add the following attributes to the TM variable:

   :_CoordinateTransformType = "Projection";
   :_CoordinateAxisTypes = "GeoX GeoY";



Stuart Wier wrote:

John,

 >
 > can you send the acctual netcdf file, or put it on ftp?
 >

It is on http://geon.unavco.org/unavco/NETCDF/Kanto_m8.nc

I also have the latitude and longitude for each grid point, 6020 unique locations, if that would help. But they do not form a regular grid with uniform spacing so I could not see how to make them into dimensions for a grid.

Thanks for your help

Stu

Hi stu:

can you send the acctual netcdf file, or put it on ftp?

Subject:
IDV - NetCDF format for xyz data grid mapping to transverse Mercator
From:
"Stuart Wier" <wier@xxxxxxxxxx>
Date:
Wed, 21 Dec 2005 11:04:44 -0700 (MST)
To:
support-idv@xxxxxxxxxxxxxxxx

To:
support-idv@xxxxxxxxxxxxxxxx


Institution: UNAVCO
Package Version: 1.2b2
Operating System: linux
Hardware Information: the usual

Inquiry: I have a GEON IDV user who has a regular xy-depth grid with 5 km spacing, and knows the mapping to a transverse Mercator projection. I made a NetCDF file whose CDL is attached. The NetCDF file appears in the IDV as a 3d grid ok, the depth levels are ok, but it seems the x and y values are taken for lon and lat. Can the cdl header information be changed so this will appear at the true grid location, a small area near 139 E, 36N?

This looks to be a pretty standard kind of upper mantle data in the solid earth sciences so I expect to see a continuing demand for use of data like this in the IDV.

Is "false_easting" required for the transverse mercator mapping? I am not clear what it is for.

Stuart

Most of the parameter data values are cut from the file to save space.