[Sample B: Approval/Signature Sheet] - George Mason University

tracking algorithm. These steps are those performed in the ground processing system
described above. The portions within the dashed lines are the steps involved in the
approach. As mentioned earlier, new track initiation is not considered in the research.
Object sighting message (OSM)
Correlate
With star?
Y
Calculate
Bias
Next star Vector
N
Perform Bias
Correction
Bias
estimate
Bias at t k
Bias Filter
Get next
star vector
Existing
Track?
Y
Calculate
Target Location
OSM from other satellite
Y
N
P tk
State
Vector
X tk+1
Star at
t k+1 ?
N
X tk
Create new
track
Figure 6. Bias Correction and Tracking Algorithm Flow Chart
3.2. Simulation modeling
The development and testing of dynamic bias correction and tracking algorithm
proceeded in four phases. Phase I tested the effect of bias on the space tracking system.
Phase II included testing of the star detection and sorting algorithm. The third phase
compared the performance of the three nonlinear estimation filters following bias
correction. Additionally, we tested the estimator‟s performance against the Cramer-Rao
lower bound (CLRB) and check for filter consistency. Finally, in Phase IV we tested the
31