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Abstract

The invention is a method of orienting a satellite in a geosynchronous orbit so as to direct a beam from an antenna mounted on the satellite to cover a desired target site, and pointing the beam axis at a desired bore site target. One embodiment of the method according to the invention includes a step of orienting the spin axis of a geosynchronous satellite at a direction angle which equals the inclination angle of the current orbital plane plus an adjustment or correction angle (.beta.), when the inclination angle is greater than zero. The correction angle is determined using one or both of the following equations: .beta.=BS-tan.sup.-1 {[ sin (bs-I)]/[6.61-cos (bs-I)]}, or .beta.=.vertline.-(BS-tan.sup.-1 {[ sin (bs+I)]/[6.61-cos (bs+I)]}).vertline., where, BS=the elevation angle of the bore site target in spacecraft coordinates, bs=the latitude of the bore site target, I=the inclination angle of the orbital plane with respect to the equatorial plane, and .beta.=the correction angle with respect to orbit-normal to point the axis of the beam at the desired bore site target. The step of orienting the satellite at the direction angle is performed by using thrusters. A magnetic torquing system could also be used.

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First Claim