Hi Steve,
If I'm interpreting the class summary page correctly, I think Grav Pulse Detection Sensors need to be a LOT more sensitive.
I've got an active sensor MR15000-R15, which the tech report page (ctrl-F7) says has detection strength 100 and a max range of 15m km. I'm at lowest sensor tech, so this thing takes up 10 HS.
I've also got a GPD10-50 sensor that takes up the same hull size (again, lowest tech), which the class summary page says has a detection range of 5m km at strength 100. It seems to me that this means that the active sensor has a range that's 3 times as big as an equivalent size passize sensor. For the same hull size (and tech level), I can make an active MR500000-R500 sensor, which has a range of 500m km - 300 times as large as the corresponding passive sensor.
[time passes]
I was going to say "I think you should crank the sensitivity of GPD up by a factor of 100" until I realized the last bit above - that would still leave passive detectors a factor of 3 shorter ranged than the longest range equivalent active sensor (and something like a factor of 2500 longer ranged than an MR200-R0.2, which seems too much). I now think that the thing to do is change the model for active sensors - I think the problem lies in the range/resolution trade-off.
This combines with something else that's been bothering me about active sensors - the fact that a high-resolution fire control for detecting missiles is blind as a bat when looking for things that are bigger than a missile. I think that the resolution idea is a really important one, I just think it needs to be modeled in a way similar to beam weapons - it's essentially
exactly the same concept that you deal with through the "focal length" tech line. The idea is that an active sensors range depends on how much energy it can concentrate along a particular bearing - a more focused emitter should have a longer range. The range/size trade-off would just come from the relative cross-sections - if a missile is 100x smaller than a ship, you can only detect it at 1/100th of the range. (Note that this is using "linear physics" - the real answer for active sensors should be something like the fourth root of (1/100), i.e. about a factor of 1/3.)
So the idea is the following - introduce a new "Active Grav Sensor Focusing" tech line that behaves the same way as focal length for beam weapons - it's a straight multiplier on the range. Since the passive GPD tech is an indicator of how sensitive your receivers are, I would include that factor in the range as well. So the detection range would go something like (again, using linear physics):
Emitter strength = (Antenna size)*(Active strength tech)*(Active focusing tech)
Range = (Emitter strength)*(target size)*(GPD tech)
Note that the emitter strength is just the relative strength of a pulse hitting the target, the middle term is the amount of energy reflected from the target, and the last term is the efficiency of detecting the returned energy. This also gives one 4 knobs to twiddle when designing active sensors - 3 tech levels plus antenna size.
Passive detection range now becomes something like:
Detector strength = (Antenna size)*(GPD tech)
Range = (source emitter strength)*(fudge factor)*(detector strength)
where "fudge factor" is a fairly large factor (like maybe 1000 or 10000)intended to account for the fact that the emitted energy doesn't have to bounce off a target and return (which is why passive detection is so much longer-ranged than active). I think this is pretty much what you've already got coded up. Now that I think of it, this whole proposal is probably pretty close to what you originally had for active sensors.
From a gameplay point of view I think this has the following advantages:
Puts the interaction between active sensors and passive detectors on a more understandable footing - passive always has a huge range advantage.
You can't squeeze more and more range out of an active sensor by going to coarser resolutions.
Eliminates the "all or nothing" effect in active sensor design - currently if I guess wrong about minimum hull size (say 50 HS when the target is actually 45 HS) then I can't see target ships that are too small at all, even if they're 100x closer.
Puts the target size/detection range back in. A particular active sensor should be able to see a bigger target from further away. Unless I misunderstand, the present system doesn't have that effect - to detect a bigger target farther away, you have to have a longer ranged sensor installed. Now that I think of it, I think this is the fundamental issue with the present system - all targets are treated the same (visible or invisible) for a given active sensor design.
Hope you like the idea,
John
PS - I realize you were tyring to model things like pulse repetition rates and emitter frequency with the current system - I just think the abstraction for them isn't working. If you're concerned about wanting to simulate the fact that there are a lot of specialized radars on a naval warship, I would say that that's already in the game with the speed/tracking range tradeoffs in fire control.