An electro-optical pre-compensating method for forming a near diffraction limited size beacon at a non-cooperative target, the method comprising the steps of:
- a) forming a steering mirror to correct a partially coherent laser for pointing errors;
- b) passing the partially coherent laser through a beam splitter for a scoring laser beam injection;
- c) using a beam splitter for sampling passive or active full target illumination for imaging and tracking;
- d) using a phase correction device to pre-correct the partially coherent laser for higher order aberrations followed by a correction for fine tracking errors;
- e) focusing the partially coherent laser via a telescope to the end target;
- f) passing the reflected pulsed partially coherent laser beam back through the telescope which re-collimates the reflected pulsed partially coherent laser beam and passes it through the pointing correction and phase correction;
- g) passing the reflected pulsed partially coherent laser beam through the beam splitter and reflected by the sensor sample process to the wavefront sensor;
- h) using the wavefront sensor to focus the reflected pulsed partially coherent laser beam and to direct a sample of the reflected pulsed partially coherent laser beam to a high speed detector functioning to measure the power in a diffraction limited size area sampled beam;
- i) using the sample of the reflected pulsed partially coherent laser beam to determine the metric gradient JPIB due to a set of modal command patterns applied to the phase correction device, the metric defined as,
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- j) using the gradient information to update a modal control command to a modal signal;
- k) using the wavefront sensor to send a sample of the reflected pulsed partially coherent laser beam to a filter and using a diffraction limited size waveplate at the focal plane to rotate the central diffraction limited size part of the reflected pulsed partially coherent beam by 90 degrees, collimating the sample of the reflected pulsed partially coherent beam, forming and measuring two fringe patterns, using the difference in the fringe patterns, being proportional to the derivative of the coherence function over the region of a control channel, as a fine control signal functioning to maximize the coherence on each channel;
- l) summing the modal signal and the fine control signals and adding a perturbation to a phase correction device and providing the perturbation information to the metric gradient computation process (JPIB);
- m) using the final summed signal to control the phase correction device and the pointing correction;
- n) receiving the full illumination of the reflected pulsed partially coherent laser beam by the telescope, correcting for turbulence by the pointing error correction and then sampling the corrected reflected partially coherent laser beam;
- o) passing the corrected reflected pulsed partially coherent laser beam through the beam splitter, reflecting the sample of the corrected reflected partially coherent laser beam to the wavefront sensor and using the sample of the corrected reflected partially coherent laser beam to update the control commands to maximize the coherence of the wavefront over the spectral band generating control commands for the phase correction device and fine pointing correction system;
- p) receiving the full illumination of the reflected pulsed partially coherent laser beam by the telescope, correcting the full illumination of the reflected pulsed partially coherent laser beam for turbulence by the pointing correction system and phase correction processes, and sampling the full illumination of the reflected pulsed partially coherent laser beam for the imaging system;
- q) processing the reflected pulsed partially coherent laser beam image to compute pointing commands for the outgoing partially coherent laser and the scoring laser, correcting the scoring laser for pointing errors and injecting the scoring laser beam into the optical path;
- r) passing the scoring laser beam through the sensor sampling beam-splitter and imaging sampling beam-splitter and pre-correcting the scoring laser beam for the effects of turbulence by the phase correction device and the pointing correction device;
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- s) joining the pre-corrected scoring laser beam with the pulsed partially coherent laser beam at the telescope functioning to focus both beams to the target.