example a satellite orbiting the earth along an actual orbit trajectory 106 an estimated orbit trajectory 108 discussed below is shown as a dashed line an arrow 110 identifies an illustration of an exemplary u201c initial acquisition u201d according to the present invention an arrow 112 identifies an illustration of an exemplary u201c cross track verification u201d according to the present invention an arrow 114 identifies an illustration of an exemplary u201c in track verification u201d according to the present invention fig2 is a flow diagram of an exemplary method 200 of tracking a moving signal source according to the present invention prior to the actual tracking event step 202 comprises employing a test trajectory to verify that the antenna accurately responds to pointing commands the commanding verification 202 is further discussed with reference to fig3 next an initial acquisition step 204 is performed for a satellite application the time variation of the position of the satellite is described by the ephemeris the satellite ephemeris and the location of the earth terminal can be used to obtain an estimated time trajectory 214 of the motion of the antenna in azimuth and elevation while the satellite is in view of the antenna the satellite is acquired both in terms of receiver acquisition of the signal and antenna alignment with the satellite position additionally the earth terminal is capable of displaying the instantaneous position of the antenna azimuth and elevation variations the initial acquisition step 204 is further discussed with reference to fig5 next a correct trajectory step 206 and a trajectory validation step 208 are performed a comparison between the ephemeris prediction of the antenna trajectory and the actual antenna trajectory facilitates determining the accuracy of the ephemeris trajectory and maintaining pointing at.