“but there is some thought that the GLONASS satellites’ secondary purpose is actually global *surveillance*.”
That makes it more interesting indeed. The article was very lacking in any sort of detail.
The GLONASS system is good enough to get one to the general area of a target, but I sure wouldn’t want to use it for anything critical. It has a minimum inherent vertical error of +/- 70 *meters* and a minimum horizonal error of 57 *meters*.
Compare that to GPS, which starts off with a base error of only 30 *centimeters* (about a foot or so).
That said, the GLONASS satellites are surprisingly large (1400+kg) when compared to a GPS satellite (770kg) and appear to have an antenna complex on them that doesn’t have anything to do with the primary purpose of broadcasting navigation signals.