Orbital sensor platform

From Memory Alpha, the free Star Trek reference

Orbital sensor platforms are a type of sensor satellites used by the Bajorans.

In 2371, Prophet's Landing installed several platforms during Kira Nerys and Odo's review of security for the colony. It was planned that they would alert the colonists of the approach of Cardassian starships, if the Cardassian Union violated the treaty. (DS9: "Heart of Stone")