Do people find it practical to build sensor buoys to monitor warp points? I have been puzzling over what kind of design priorities there were for them.
First, the sensor has to have range to cover any transit, and detect any ship capable of surveying.
Second, it needs to have endurance so that you don't have to send a ship out to replace it.
Third, it needs to be of small enough size or distant enough from the warp point that it will not generally be discovered by ships that pass through.
Fourth, it needs to be cheap enough to be used everywhere.
It is the third criteria which seems to cause the hang ups. If an invading fleet has anti-missile missiles, it can be counted on to have a resolution 1 sensor that can reach over a million km.
So this suggests that you can't have one sensor buoy design meet all of those tests. So having a buoy that can cover the warp point and detect anything is going to be fairly myopic, and therefore close to the warp point. But a buoy that is used to track the entry of capital ships, with a resolution 60 or so, can have much more range and conceivably escape detection.
I am also curious about Captor mine designs. The larger the mine, the better the sensor, and the less cost per submunition to get a given range sensor trigger. But that larger mine is also easier to detect, and that range allows an invader to get their sensors up or jump back through the warp point.
For myself, I am dubious about how effective Captor mines are in a warp point defense, as an invader could send in a big noisy ship to trigger their launch, and then just slip back through the warp point. But if you use them in open space, you really need as much range as possible, which makes the larger mines more economical.