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Sky-coverage in laser-assisted AO observations largely depends on thesystem's capability to guide on the faintest natural guide-stars possible. Herewe give an up-to-date status of our natural guide-star processing tailored tothe European-ELT's visible and near-infrared (0.47 to 2.45 {\mu}m) integralfield spectrograph - Harmoni. We tour the processing of both the isoplanaticand anisoplanatic tilt modes using the spatio-angular approach whereby thewave-front is estimated directly in the pupil plane avoiding a cumbersomeexplicit layered estimation on the 35-layer profiles we're currently using.Taking the case of Harmoni, we cover the choice of wave-front sensors, thenumber and field location of guide-stars, the optimised algorithms to beat downangular anisoplanatism and the performance obtained with different temporalcontrollers under split high-order/low-order tomography or joint tomography. Weconsider both atmospheric and far greater telescope wind buffetingdisturbances. In addition we provide the sky-coverage estimates thus obtained.

Natural guide-star processing for wide-field laser-assisted AO systems