Using signals from GPS satellites, an ONR-funded researcher has developed a much more precise method of locating intercontinental-range ballistic missiles and other exo-atmospheric (space) targets. Electromagnetic signals from space are bent by the atmosphere much the same way light is bent when it passes through water. Existing tracking methods use climatological data to deduce the amount of bending the signal should incur due to air moisture and temperature.
Because these deductions are not always entirely accurate, the target's actual location and its presumed location can be off by several miles. A researcher at University Corporation for Atmospheric Research (UCAR) in Boulder, Colo., has devised a way to make this tracking more accurate.
Using a radio instrument to first track GPS satellites, whose exact positions are known, the amount of bending the signal is enduring in a certain atmospheric region can be determined. A target's signal in the same atmospheric region should be experiencing the same degree of bending due to similar atmospheric conditions, and thus an accurate position for the target is discovered. This technology has applications in high-precision tracking radars.
"The preliminary results are very successful," said ONR Program Manager Scott Sandgathe, "but it will need to be tested in more environments and seasons" before it finds its way into the Fleet. The next planned experiment will take place in southern California during September to coincide with the strong Santa Anna winds.