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Re: Inverse Map Projection Help [message #58917 is a reply to message #58825]

Mon, 25 February 2008 12:11

Paul Levine
Messages: 29
Registered: February 2008

Junior Member

On 2008-02-25 06:56:50 -0800, mankoff <mankoff@gmail.com> said:

> On Feb 24, 2:54ï¿½pm, Paul Levine <paul.lev...@ucla.edu> wrote:
>> On 2008-02-22 09:48:38 -0800, mankoff <mank...@gmail.com> said:
>>
>>
>>
>>>> > Polar Stereographic projection with 71=B0S as the latitude of true s
> cale
>>>> > and 0=B0E as the central meridian.
>>
>>> ;; this is the projection the data is distributed on
>>> stereo = map_proj_init('Polar Stereographic', /GCTP, DATUM=8, $
>>> ï¿½ ï¿½ ï¿½ ï¿½ ï¿½ ï¿½ ï¿½ ï¿½ ï¿½ ï¿½ ï¿½ ï¿½CENTER_LONGITUDE=0, CEN
> TER_LATITUDE=-90)
>>
>> You must change the CENTER_LATITUDE to -71
>>
>> Polar stereographic projections are free of aereal distortion at only
>> one latitude, with aereal distortion increasing both north and south of
>> this latitude. ï¿½In the case of your data, that latitude is 71 south. ï¿½
>
>> FWIW, the northern-hemisphere sea ice data distributed by the NSIDC is
>> centered at 70 north.
>>
>> HTH,
>> Paul
>
> It does help. Image is better aligned. But still not accurate :(.

Is the inaccuracy greater or lesser than one pixel?

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[Message index]

		Inverse Map Projection Help By: mankoff on Mon, 18 February 2008 17:47
		Re: Inverse Map Projection Help By: mankoff on Mon, 25 February 2008 06:56
		Re: Inverse Map Projection Help By: David Fanning on Tue, 26 February 2008 04:43
		Re: Inverse Map Projection Help By: mankoff on Tue, 26 February 2008 18:12
		Re: Inverse Map Projection Help By: Paul Levine on Mon, 25 February 2008 12:11
		Re: Inverse Map Projection Help By: Paul Levine on Sun, 24 February 2008 11:54
		Re: Inverse Map Projection Help By: mankoff on Wed, 27 February 2008 16:09
		Re: Inverse Map Projection Help By: David Fanning on Tue, 26 February 2008 20:56

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