Arduino Communication

For my science fair project, I am measuring the amount of solar energy generated from different heights. For this, it can't all be on one arduino, so I need to be able to communicate between more than one. The solar panel is on A1, and the barometric pressure sensor is on A4 and A5 (measures pressure and temperature to generate altitude). I want this to all be displayed on a lcd shield on a different arduino. It would be great if anyone could help

what are the differences in the heights? 100, 200, 500 mtr? Is there line of sight?

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