Re: transform a projection into regular lat-lon

Does
    http://www.ncl.ucar.edu/Applications/rotatedltln.shtml
answer your question. Please read the text.

Good Luck

On 2/27/12 3:31 AM, Mark Chan wrote:
> Dear NCL users,
>
> I have a model output file having info as in the below. I was told it is
> "rotated projection" (I don't know exactly what it is).
> Could any one help give me a suggestion how to transform this data into
> regular lat-lon projection? The main issue is how to define its
> projection when reading it with NCL?
>
> Thanks so much in advance!
> Mark Chan
>
> ----------------------Data file info ------------------------
> dimensions:
> ncl_scalar = 1
> rlat = 92
> rlon = 108
> time = 87648 // unlimited
> height_2m = 1
> variables:
> double time ( time )
> standard_name : time
> units : seconds since 1989-01-01 00:00:00
> calendar : standard
> float rlon ( rlon )
> standard_name : grid_longitude
> units : degrees
> float rlat ( rlat )
> standard_name : grid_latitude
> units : degrees
> float lon ( rlat, rlon )
> standard_name : longitude
> units : degrees_east
> float lat ( rlat, rlon )
> standard_name : latitude
> units : degrees_north
> float height_2m ( height_2m )
> long_name : height above surface
> units : m
> character rotated_pole ( ncl_scalar )
> long_name : coordinates of the rotated North Pole
> grid_mapping_name : rotated_latitude_longitude
> grid_north_pole_latitude : 39.25
> grid_north_pole_longitude : -162
> short tas ( time, height_2m, rlat, rlon )
> standard_name : air_temperature
> long_name : 2m temperature
> units : K
> coordinates : lon lat
> scale_factor : 0.004940663
> add_offset : 161.8932
> ====================================
>
> -----------------Its grids info is
> as-----------------------------------------------------
> rlon = -10.445, -10.335, -10.225, -10.115, -10.005, -9.895, -9.785, -9.675,
> -9.565, -9.455, -9.345, -9.235, -9.125, -9.015, -8.905, -8.795, -8.685,
> -8.575, -8.465, -8.355, -8.245, -8.135, -8.025, -7.915, -7.805, -7.695,
> -7.585, -7.475, -7.365, -7.255, -7.145, -7.035, -6.925, -6.815, -6.705,
> -6.595, -6.485, -6.375, -6.265, -6.155, -6.045, -5.935, -5.825, -5.715,
> -5.605, -5.495, -5.385, -5.275, -5.165, -5.055, -4.945, -4.835, -4.725,
> -4.615, -4.505, -4.395, -4.285, -4.175, -4.065, -3.955, -3.845, -3.735,
> -3.625, -3.515, -3.405, -3.295, -3.185, -3.075, -2.965, -2.855, -2.745,
> -2.635, -2.525, -2.415, -2.305, -2.195, -2.085, -1.975, -1.865, -1.755,
> -1.645, -1.535, -1.425, -1.315, -1.205, -1.095, -0.985, -0.875, -0.765,
> -0.655, -0.545, -0.435, -0.325, -0.215, -0.105, 0.005, 0.115, 0.225,
> 0.335, 0.445, 0.555, 0.665, 0.775, 0.885, 0.995, 1.105, 1.215, 1.325 ;
>
> rlat = -8.855, -8.745, -8.635, -8.525, -8.415, -8.305, -8.195, -8.085,
> -7.975, -7.865, -7.755, -7.645, -7.535, -7.425, -7.315, -7.205, -7.095,
> -6.985, -6.875, -6.765, -6.655, -6.545, -6.435, -6.325, -6.215, -6.105,
> -5.995, -5.885, -5.775, -5.665, -5.555, -5.445, -5.335, -5.225, -5.115,
> -5.005, -4.895, -4.785, -4.675, -4.565, -4.455, -4.345, -4.235, -4.125,
> -4.015, -3.905, -3.795, -3.685, -3.575, -3.465, -3.355, -3.245, -3.135,
> -3.025, -2.915, -2.805, -2.695, -2.585, -2.475, -2.365, -2.255, -2.145,
> -2.035, -1.925, -1.815, -1.705, -1.595, -1.485, -1.375, -1.265, -1.155,
> -1.045, -0.935, -0.825, -0.715, -0.605, -0.495, -0.385, -0.275, -0.165,
> -0.055, 0.055, 0.165, 0.275, 0.385, 0.495, 0.605, 0.715, 0.825, 0.935,
> 1.045, 1.155 ;
>
>
>
>
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Received on Mon Feb 27 09:39:46 2012