During the cold war, it was often claimed that spy satellites could read the headline of a newspaper left on a park bench in Moscow or Washington DC. They couldn't: spatial resolution was nowhere near good enough. Nonetheless, the eyes in the sky were watching. Those eyes now see further and more clearly than ever before -though they probably still can't read headlines. Nor are they just the preserve of intelligence services. Increasingly, private operators are using observation satellites and drones to obtain high-resolution images and sell them to anyone who is interested.
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