[Proj] Can I convert the ellipsoids using Proj?

[Cleo Drakos]

Dear Noel

Thanks for your explanation. So it means that both ellipsoids have the same
geocentric coordinates, and I can use Jose's instruction.
I have four columns (lats, lons, elevation, and geoid) in an ASCII file. I
need to convert all these four parameters into WGS84 system.
How can I apply Jose's instruction? I mean how can I call cs2cs for
different parameters? I did not know how to input these four parameters.

Sorry for this type of question, I hope you do not mind.


cleo


On Tue, Aug 19, 2014 at 8:44 PM, Noel Zinn (cc) <ndzinn at comcast.net> wrote:

>   Cleo,
>
> FAQ #7 under Altimetry products in the link you provide seems to answer
> the question you ask.  The FTP link in that paragraph leads you to  a
> program top2wgs.pro that solves your problem.  The program assumes dX =
> dY = dZ = 0.  I’ve made the same assumption myself with TOPEX/Poseidon in
> a different context.  Then follow Jose’s cs2cs instructions.
>
> Thanks for the link.
>
> Noel
>
> Noel Zinn, Principal, Hydrometronics LLC
> +1-832-539-1472 (office), +1-281-221-0051 (cell)
> noel.zinn at hydrometronics.com (email)
> http://www.hydrometronics.com (website)
>
>  *From:* Cleo Drakos <cleo21drakos at gmail.com>
> *Sent:* Tuesday, August 19, 2014 3:39 AM
> *To:* PROJ.4 and general Projections Discussions <proj at lists.maptools.org>
> *Subject:* Re: [Proj] Can I convert the ellipsoids using Proj?
>
>  Dear Jose
>
> Thanks for your answer. Can you help me how can I make certain that both
> ellepsoids have the same geocentric coordinates.
> Only the information I am having is below under the section of How does
> the GLAS ellipsoid compare with WGS 84?
>
> http://nsidc.org/data/icesat/faq.html#3_all
>
>
>  cleo
>
>
> On Tue, Aug 19, 2014 at 6:03 AM, Jose Gonçalves <jagoncal at gmail.com>
> wrote:
>
>>  Cleo
>>
>> If cartesian geocentric coordinates are the same and you just want to
>> express them in a different ellipsoid you can do:
>>
>> cs2cs -f %.9f +a=6378136.30 +rf=298.257 +proj=latlong +towgs84=0,0,0 +to
>> +a=6378137 +rf=298.25722356 +proj=latlong +towgs84=0,0,0
>>
>> If there are shift and rotation you can express them in the +towgs84.
>>
>> Regards
>>
>> José
>>
>>
>>
>> 2014-08-18 15:13 GMT+01:00 Cleo Drakos <cleo21drakos at gmail.com>:
>>
>>>   Dear guys,
>>>
>>> I have the data (latitudes, longitudes, and elevations) given in
>>> ICESat/GLAS ellipsoid. This equatorial radius and  reciprocal flattening
>>> (1/f) on this ellipsoid are 6378136.30 m and is 298.257 respectively.
>>>
>>> Now, I want to convert my data into WGS84 ellepsoid with equatorial
>>> radius and reciprocal flattening (1/f) of 6378137.000000 and 298.25722356
>>> respectively.
>>>
>>> Can I convert the ellipsoids using Proj?
>>>
>>> I hope some of you can help me.
>>>
>>>  cleo
>>>
>>> _______________________________________________
>>> Proj mailing list
>>> Proj at lists.maptools.org
>>> http://lists.maptools.org/mailman/listinfo/proj
>>>
>>
>>
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>
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