Astrogeodetic fix by azimuth differences; Solution in rectangular coordinates

This paper offers a precise and almost final solution to one of the most de bated problems connected with the astrogeodetic 'fix' by azimuth difference s. The rectangular and linear solution on the gnomonic plane, tangent to th e celestial globe and the dead reckoning position, enables the use of azimu th differences and is connected to Pothenot's solution. Thus this problem m ay be solved with simple linear algorithms that require neither differentia l modes, nor the introduction of the unknown origin error.