The preface gives the name of the author as Abu'l Hasan al-Bayhaqi and lists the other books written by him and that he was asked to write a book on astronomy, so he collected material from different sources, and as it was requested for kings, he wrote it in Persian so that they would not need an interpreter or commentator. He wrote this book after having consulted 257 books.
The charts relate to the movement of celestial bodies. It seems that spaces were left originally for future observations to be added.
For his biography see: The Encyclopaedia of Islam, I, 1986, pp.1131-2. The above text is mentioned, and it seems that there are few known copies of this work.