Not really. We know the location of things like that with a high degree of accuracy. They follow very predictable patterns, so it is easy to know when they are overhead and when they are not.
Here, this should give an example.
New Mexico 88002
www.google.com
Now this is a testing location on the White Sands Missile Range, and one I am very familiar with. This is literally the "Birthplace of the PATRIOT Missile", right there. From the late 1960s until the middle 1970s, that is where the system was first tested and employed.
Now one of the things that stands out if you are actually there on the ground is that strange "line" that runs diagonally from lower left to upper right. Just north of the complex of buildings. That is actually a set of railroad tracks, about 30 meters from rail to rail. And the big grey thing on there is actually a building that can be moved along those rails.
Back in the 1970s when PATRIOT was first being tested, that is where it was done. And they knew when Soviet spy satellites would pass overhead. So when the satellite was close to passing over, they would move that building over the launcher so it could not be seen from space. And once it had passed they would move that building away and continue testing.
And that strange horseshoe north of the tracks and building, that is a berm where the moved the first launcher to for life fire testing. And back in the day, the entire thing was covered with camouflage netting, that could still be seen rotting inside. Continue along the tracks and out into the desert a little ways, and there is this "star" pattern. Back when they were developing and testing PATRIOT, they had a HAWK battery positioned there in the classic "Star Pattern ADA configuration".
That was not there for any kind of defense, that was camouflage and a distraction. So when the Soviets discovered that location and the activity there, they would see the HAWK battery and just assume that is all it was. That the US was improving an old air defense system, not creating an entirely new air defense system.
Then later when the first full batteries were known and being tested, they actually would employ PATRIOT in those same locations. Once again, a distraction. Because unlike other air defense systems of the era, it actually can not operate in that layout because it uses an aimed RADAR array and not the old school "spinning RADAR" that gives 360 degree coverage. By doing that, it would fool the Soviets into thinking it was just a new missile for HAWK, but the same old RADAR (which still sat in the middle). It's gone now, but a decade ago there was actually a building there that was "canted" at a 45 degree angle. Back in that phase of testing, that was the actual RADAR system they were using. And they were only using the 2 or 3 launchers that were pointing in the direction of the RADAR.
Layers upon layers upon layers of cover, camouflage, and misdirection. Primarily because they knew exactly when Soviet satellites would pass overhead, and how to quickly change it so that it looked nothing like what was really going on.
And that location was used for decades. Go a bit west down that road, and you can see the remains of what seem to be blown up places. Those were actually the original testing pads for the older NIKE system. Those were all destroyed as part of the 1972 ABM treaty with the Soviet Union.
But looking at all the things there, it can be clearly seen many of the things during the Cold War that the US did in order to keep the Soviets from finding out about it. Primarily because they knew exactly when Soviet satellites would pass overhead, and could quickly convert the location from an active top secret R&D site to just another routine testing site in the desert.
And this is something that has not changed in the decades since. That is why recently China tried using balloons for such reconnaissance. Because they were not predictable, and not known about until discovered already over the country.
