When and where did ptolemy make his astronomical observations?

Ptolemy is one of the best known astronomers, geographers, mathematicians, from the antique period. He lived in what is now Egypt, in his time it was the Roman Province of Egypt, in the city of Alexandria, the famous city of knowledge.

Not much is known about Ptolemy's life except from his scientific writings. In the year of 150 AD, Ptolemy finished his book where he had written a lot about his astronomical observations and conclusions. According to the book, he summed up observations made over a period of around 25 years, thus we can say that he was making his observations from 125 AD to 150 AD.

What made his work very important and marking is his geocentric model. Despite it not being accurate, as it had multiple mistakes, it was still the basis for further scientific observations and investigations for the centuries to come. His observations were made on the territory of Egypt, the majority of them from Alexandria itself.