Optical problem concerning space mirror.

AI Thread Summary
Designing a space-based energy satellite using a mirror to reflect sunlight to a ground photovoltaic station presents challenges due to varying angles of sunlight from different solar poles, resulting in a large illuminated area on Earth. The discussion explores potential solutions, including the use of lenses, metamaterials, or nanomaterials, but acknowledges that traditional macro devices may not effectively address the issue. A concave mirror is suggested, but it is noted that it cannot produce a sufficiently small image due to the diverse angles at which light strikes the mirror. Additionally, the constraints of mirror-image distance and focal length further complicate achieving a minimal image size. The conversation emphasizes the need for innovative approaches to overcome these optical challenges.
fatjohn
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When designing a space based energy satellite for our project, we ran across the option to just use a mirror to reflect extra light to a photovoltaic ground station on earth. The main difficulty of this option is that due to the fact that the light coming from the south pole of the sun hits the mirror with a different angle then the light coming from the north pole a 336 kilometer wide circle on Earth would be illuminated.
Is there any way to overcome this problem either with a configuration of lenses or with certain metamaterials or nanomaterials? It seems to me that at a certain (focal) point on the mirror light hits it in a various different angles. This is a problem that to my knowledge cannot be overcome with macro devices. Anybody has a proposition?

Thank you for your attention.
 
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fatjohn said:
Is there any way to overcome this problem either with a configuration of lenses or with certain metamaterials or nanomaterials?
Or you could just use a concave mirror
You are trying to make an image of the sun on the ground
 
mgb_phys said:
Or you could just use a concave mirror
You are trying to make an image of the sun on the ground

Yes I am trying to make an image of the sun on the ground but i am trying to make that image as small as possible. A concave mirror cannot do the job this is because at one point of the mirror the light comes in at a variaty of angles.
 
That is true of any lens or mirror making an image of a finite object.

You have an extra constraint that the mirror-image distance (and so focal length) is restricted which sets the minimum size of the image.
 
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