This is a summary of the processing flow at the Davie Space Operations
Center (NOT affiliated with the U.S. Navy or NORAD). Starting at the upper
left, an unknown satellite is observed within the receiver passband while using
the interferometer antenna. A preliminary set of orbital elements is generated
from the measured data as described earlier. It is used to predict the next
fence crossing, approximately 90 minutes later. Using the steerable yagi array,
this second fence crossing is monitored, and doppler and time of the signal are
measured. This additional information is used to refine the Keplerian element
set, and the process of prediction and observation can be continued
indefinitely. At any time, the measured data can be compared against
predictions based on NORAD's orbital element database to identify the satellite
being observed. A computer program was written which steps through the
predictions of 4000 satellites in about 20 minutes, comparing each satellite's
predicted doppler and time of fence crossing to the values actually measured. A
match is declared when the values agree within .25 seconds and 3-4 Hz.
