During the Arab domination of the Iberian Peninsula, many astronomers from Granada or linked to Granada are worth mentioning. Among them, two mathematicians-astronomers, father and son, Hasan and Ahmad Ibn Baso, stand out. Unfortunately, very little is known of their lives. Ibn Baso wrote two well-known treatises on astronomy and introduced an innovation in the astrolabe that made it possible to use it on all horizons. The Ibn Baso were in charge of the construction of astronomical instruments. In the Museo della Specola in Bologna, Italy, there is a copy of an astrolabe attributed to Ibn Baso, Sr., the probable date of its construction is 1280 AD.