Abstract: A new estimation method, called the improved correlative interferometer, is presented for direction finding(DF).
Unlike the conventional correlative interferometer, which uses phase difference directly, it firstly employs trigonometric
functions of the measured phase difference to construct complex number vectors, and fits them to the array manifold which is
a continuum of response vectors of the antenna array. Since trigonometric functions are continuous at all points including
the boundary of the principal value region, this technique naturally solves the problem of the break of phase differences and
eliminates the data match error. Neither the unwrap of phase differences nor the data match among long baselines and short
ones is necessary, and thus the described approach is simple and robust. The results of numerial simulations and applied DF
systems show its validity and correctness.

Key words: direction finding(DF), correlative interferometer, array manifold fitting