Terrestrial based tracking with very high levels of GPS accuracy for most aircraft. Some older
aircraft use inertial reference units instead of GPS for positions, decreasing positional accuracy.
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Satellite based tracking with very high levels of GPS accuracy for most aircraft. Some older aircraft use
inertial reference units instead of GPS for positions, decreasing positional accuracy.
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Terrestrial based tracking using the time difference of arrival to calculate position. Should
give high positional accuracy during most phases of flight, but position errors can sometimes occur. The
ground speed is calculated and can sometimes be incorrect, especially during turns and at low altitudes.
Vertical speed is also calculated, so errors can sometimes oc