How to Judging a point is on the front side of the Earth, not is the back side?

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How to Judging a point is on the front side of the Earth, not is the back side?
Help, Thanks!

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Hi @ranxie,

I’m not sure what you mean by the “front side” or the “back side” of the Earth. Can you provide an image that explains what you mean?

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企业微信截图_20230316091150
企业微信截图_202303160911501111×577 260 KB

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America is on the front side of the earth， Asia is on the back side of the earth。
How to Judging a point is on the front side of the Earth, not is the back side?