ScienceCast 218: Twinkle Twinkle GPS

published 4 years ago

Twinkle twinkle GPS presented by science at NASA. Go outside tonight and behold the stars. Especially bright stars low on the horizon the twinkle as irregularities in earth's atmosphere passed by. Unseen to the human eye the same thing happens to signals from GPS Global Positioning System. Radio signals twinkle in much the same way as bright stars appear to do at optical wavelengths. This can have effects on GPS causing signals to brighten and fade and reach earth at unpredictable times. All of this could degrade the accuracy of GPS position. The twin thing occurs because signals beamed to earth by GPS satellites passed through a layer of earth's atmosphere called the ionosphere. Irregularities in the ionosphere referred to as ionosphere completions or bubbles in the science community. Span hemispheres at the equator an army ...

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