Patent ID: 6079666
Filing Date: 2000-06-27
Classification: F41G

Abstract:
A boresight error slope reduction system for sensing, in real time, a boresight error slope in a homing seeker, said system comprising:(a) a seeker having a steerable field-of-view, said field-of-view having an electrical boresight axis, and(b) a receiver wherein a wide bandwidth video signal voltage is obtained when an object is within said field-of-view, said object being on a line-of-sight from said seeker causing an included angle between said line-of-sight and said boresight axis, said video signal voltage being a function of said included angle, and(c) a tracking loop having a means for using said signal voltage to steer said field-of-view so that said object remains within said field-of-view and a means for generating a low-pass filtered dynamic lag voltage from said video signal voltage, and(d) a dither waveform generator wherein a dither voltage is generated and(e) a means for using said dither voltage to cause a dither of said boresight axis and(f) a means for causing said tracking loop to be open during said dither of said boresight axis and(g) a boresight error slope computer circuit for generating a transfer characteristic having a measurable curvature, said transfer characteristic being a voltage functionally related to said included angle, said angle resulting from said dither, and(h) a boresight error slope computer circuit for generating a correction voltage, said correction voltage being a function of said curvature of said transfer characteristic in a neighborhood of said line of sight, and(i) an additive means for using said correction voltage to reduce said boresight error slope.