Full-Disk Orthographic to Cylindrical Projection [message #83545] |
Mon, 11 March 2013 10:48 |
Tyler Behm
Messages: 2 Registered: March 2013
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Junior Member |
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I have full-disk ground-based solar images. They can be thought of as satellite-projection maps of the Sun. I am trying to work my way up to projecting these images to cylindrical by starting with the easier case of full-disk Earth orthographic projections.
I have been using IDL's map_set to produce orthographic images of the Earth. When I use map_proj_init or poly_warp to transform this orthographic Earth image into a cylindrical projection, it is definitely not correct. I think that IDL is also warping the corners of the orthographic image which are outside the mapping. How can I transform only the circular disk of the Earth (or Sun)?
window, 0, xsize=600, ysize=600
map_set, /orthographic, /grid, /conti, /hori, xmar=0, ymar=0, /iso
ortho=tvrd()
omap=!map
cmap=map_proj('Cylindrical')
cylin=map_proj_image(ortho, omap.uv_box, image_str=omap, map_str=cmap)
tvscl, cylin
Thank you in advance.
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