Custom coordinate systems - Longitudinal ranges

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03-17-2017 10:29 AM
ChristineHomuth
New Contributor II

I'm using the SimpleCylindrical_Titan coordinate system, which has a range of 180W to 180E.

Data for Titan (Saturn's moon) typically ranges from 0 to 360W, centering on 180.

Is there any way to alter the range of values in order to display properly from 0 to 360, rather than 180 to 180?

Thank you,

Christine

5 Replies
JimCousins
MVP Regular Contributor

Interesting question. I am assuming you wish to create this coordinate system for use in ArcGIS, so I am adding  Melita Kennedy as a keyword here, as she will see it since it references her. She is Senior Product Engineer for Map Projections and Transformations at ESRI, and your best bet for a solution.

Best Regards,

Jim

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ChristineHomuth
New Contributor II

Hi Jim and Melita,

Yes, I was trying to create a custom coordinate system. I'm able to change the central meridian (180), but not the range (0 to 360, positive west).

The coordinate system is based on SimpleCylindrical_Titan, with the following ranges and radii:

  CenterLongitude    = 180.0

  EquatorialRadius   = 2575000.0 <meters>

  PolarRadius        = 2575000.0 <meters>

  LongitudeDirection = PositiveWest

  LongitudeDomain    = 360

  MinimumLatitude    = -90.0

  MaximumLatitude    = 90.0

  MinimumLongitude   = 0.0

  MaximumLongitude   = 360.0

Christine

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JimCousins
MVP Regular Contributor

out of curiosity, what happens if you set the CenterLongitude = 0.0 ?

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MelitaKennedy
Esri Notable Contributor

I don't know that we can do anything directly. I think it will be easier to re-georeference the data. Note the "postiveWest" for the LongitudeDirection value. You could just force the raster into 0-360 latitude/longitude that way. Or possibly georeference into a simple cylindrical system, center at 180. 

Melita

ChristineHomuth
New Contributor II

Ok, thank you Melita!

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