Figure 10.1: An example of an error-angle update from the ground station at orbital
phase ≈ −0.2633 (top graph). The graph shows the evolution of the three error
angles over a time interval of just over 25 min for orbit 145 (8 January 1990). The
update is “removed” by applying it in retrospect to all preceding data (bottom
graph). The red, blue and black curves refer to the x, y and z axes respectively.