With long range radar it is hard to tell the altitude.
The bearing is easily ascertained accurately because of the angle the antenna points in and its sweeping through a full circle.
The distance is easily ascertained accurately from the delay of the transmit to the echo - delays can be resolved to extremely small increments.
The altitude is hard to discern because the radar beam is fairly wide and not swept up and down as it is side to side. its also a relatively small elevation angle so small errors in approximating elevation translate to large vertical height errors at distance.
When they say it was at such and such lat and lon I can believe it. When they say it was headed in such and such direction I can believe that they took two lat lon positions at slightly different times and plotted the direction and speed. But when they say it went from 23000 ft to 45000 feet I take that with a grain of salt. Overall the altitude data is the hardest to believe.
The bearing is easily ascertained accurately because of the angle the antenna points in and its sweeping through a full circle.
The distance is easily ascertained accurately from the delay of the transmit to the echo - delays can be resolved to extremely small increments.
The altitude is hard to discern because the radar beam is fairly wide and not swept up and down as it is side to side. its also a relatively small elevation angle so small errors in approximating elevation translate to large vertical height errors at distance.
When they say it was at such and such lat and lon I can believe it. When they say it was headed in such and such direction I can believe that they took two lat lon positions at slightly different times and plotted the direction and speed. But when they say it went from 23000 ft to 45000 feet I take that with a grain of salt. Overall the altitude data is the hardest to believe.
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