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Precise altitude measurements of LEO objects with simultaneous observations by multiple telescopes

The increase in the number of satellites and space debris in low Earth orbit (LEO) makes tracking these objects and avoiding collisions a major endeavor. A particularly important issue is the determination of the altitude of these objects, which in many cases is not known with a precision better than 1 km. Here we present the idea of using simultaneous observations by 2 optical telescopes, separated by a few hundred km, to refine the altitude measurement of these objects to a precision of 10 m. We discuss the requirements for such a system, like aperture, timing precision, and the precision to which one needs to know the positions of the telescopes and background stars.