Question

what function does an observatory perform

Answer 1

to check the atmosphere factors such as temperature, pressure, velocity of wind and humidity

Answer 2

The professional work of an observatory depends upon the observation he she does......
There are many observatories in different fields.......
1) astronomy- he observes the changes , that occur in the outer space.
2) Temperature- observe the decrease ( downfall ) / increase in the temperature.
3) Weather - they observe the weather conditions and the climatic conditions of different portions and regions of the earth.....
Also of different planets, around the Universe....
That's why they send weather forecasting balloons for help...
4) Gravitational waves too are checked.... Cosmic rays in cosmology means studies and observations about stars....
5) Tidal waves too are included....
6) Predictions: of any disasters or anything....
7) Invention or discovery of new celestial bodies etc....

Observatories are usually minute observers who have complete presence of mind and full concentration....
Hope it helps!