Radio plasma fringes as guide stars: tracking the global tilt

We present a novel technique to alleviate the problem of the global tilt in artificial guide stars for adaptive optics. This technique is based on the registration of trails of radio-excited plasma spots caused by the atmosph eric tilt. Following the time trace of the trails one can find and measure the tilt produced by atmospheric turbulent layers. Different methods were a pplied to estimate the extent of the trails. We describe results of compute r simulations, showing the performance of the proposed approach.