Re: sperical coordinate system in ncl

Dear Christof,

in NCL a rotated lat/lon is a "CylindricalEquidistant" projection. The
two code snippets below should help you to get either the native
projection or transform to another projection. In the latter case you
need the lat/lon in 2d arrays. The first method gets the grid
information (corner points and pole) from a GRIB file, but NetCDF should
provide the same information.

  ; for native grid plot

  res@mpProjection = "CylindricalEquidistant" ; projection
  res@mpLimitMode = "Corners" ; method to zoom
  res@mpLeftCornerLatF = b->g10_lat_0@corners(0)
  res@mpLeftCornerLonF = b->g10_lon_1@corners(0)
  res@mpRightCornerLatF = b->g10_lat_0@corners(2)
  res@mpRightCornerLonF = b->g10_lon_1@corners(2)
  res@mpCenterLonF = b->g10_lon_1@Longitude_of_southern_pole
  res@mpCenterLatF = b->g10_lon_1@Latitude_of_southern_pole + 90.
  res@tfDoNDCOverlay = True ; dont transform data

  res@tmXBOn = False ; tickmarks are wrong anyway
  res@tmXTOn = False
  res@tmYLOn = False
  res@tmYROn = False

 ; for regular lat/lon projection

  resLatLon@trGridType = "Curvilinear"
  resLatLon@sfXArray = lon2d
  resLatLon@sfYArray = lat2d
  resLatLon@mpLimitMode = "LatLon"
  resLatLon@tfDoNDCOverlay = False
  resLatLon@pmLabelBarOrthogonalPosF = 0.20

Hope that helps,
Axel

Am Mittwoch, den 20.01.2010, 14:52 +0100 schrieb Christof Wilhelm:
> Dear ncl-talk readers,
>
> is there a possibility in ncl to plot geographical coordinates in a
> spherical coordinate system?
>
> The background is the following, that I generally want to find a method
> to plot REMO output with ncl.
> REMO output comes on rotated geographical coordinates.
>
> I tried it with the method of native grids following the link below, but
> couldn't solve the problem, because the REMO data are not projected in
> any of the common ncl projections.
>
> http://www.ncl.ucar.edu/Support/talk_archives/2009/0052.html
>
>
> THX for any help,
> Christof
>
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Received on Wed Jan 20 09:37:01 2010