20000719: GINI to netCDF (cont.)

>From: David Harper <address@hidden>
>Organization: NCAR/RAP
>Keywords: 200003012325.QAA04248 McIDAS-X GINI netCDF

Dave,

- back at the comparinson -

Since I don't have a way of displaying imagery in netCDF here at
Unidata, I decided to compare a couple of LAT,LON pairs from the netCDF
file I grabbed from your machine yesterday (GINI0001.nc) with the AREA
file copy I made of the same GINI data.  I compared the upper left and
lower right points of the image by doing an ncdump on the netCDF and a
load and interrogation in McIDAS.  Here are the quicky comparisons:

point        netCDF Lat,Lon [deg]  McIDAS AREA Lat,Lon [deg]
------------+---------------------+-----------------------------
1,1          36.32418N  110.7891W  36.32222N  110.79055W
800,800      29.71597N  101.4901W  29.71333N  101.49055W

You can see that the the Lats and Lons from the upper right and lower
left hand corners of the image in AREA and netCDF forms agree to one to
two parts in one thousand.  This is significantly less than the half a
degree offsets that you are seeing.

My conclusion from this simple comparison is that the GINI to netCDF
conversion is working correctly.  The 0.5 degree offset you are seeing
must be coming from somewhere else.

Tom