IIRC, the Sentinel was indeed sold as a stealth ship, capable of wild weasel. It's the only Vanguard with radar absorbing armor and an EM box around the reactors. It did produce a much lower EM signature than the others until the weapons nerf at 3.14, and I hadn't noticed it was put back until yesterday. So two things: first, to get numbers that compare to the other ship variants you have to shut the EMP off. It has never generated stealth numbers with the EMP or shields active. When 3.14 hit was the first time small ships had shields that could be left on and still have a stealthy signature. I think that's still true and for this reason I only compare numbers with all weapons and shields off. This is more useful anyway. I think they want to force you to choose between roles, and whether to leave your weapons, engines and shields on, since shields and EMPs take time to charge. (To unpower a component in erkul, click the green vertical bar on the right side of the component in the layout. It should turn grey to power off. Powering and unpowering components is a huge part of stealth gameplay.)
Second, I believe detection range is EM or IR, whichever is higher, multiplied by 0.5 for a small radar/sensor suit, 0.75 for medium (S2), 1.0 for large and 1.5 for cap class. Also the stealth switch moves about 25% of your IR to EM, so you'll use it if you have a much lower EM than IR. In general, stealth ships have an EM signature that is
lower than their IR, so when they flip the stealth switch it actually improves their signature. This is NOT true of many ships. I have never found the toggle representing the stealth switch in erkul, so I think you have to do this calculation yourself. In the instance where the Sentinel has everything off, its IR is 6,487 and its EM is just 543, so with
full sneak enabled the larger sig should be IR at 4865 and its detection range should be S1=2.4km, S2=3.6km, S3=4.9km, and S4 =7.3km. That is a tiny sig, and recall the ship has 4x4S2 missiles available so can strike from outside its detection range. This is a big deal, and affects all ships capable of small signatures that carry significant missile loads. If you carry 4 S4 launchers, in practical terms this is huge, and so far as I'm aware, was not true from 3.14 until recently--I thought 3.18. Additionally, the tiny 2.4 km detection range of small ships is less than the range of most S5 weapons, so the Sentinel would actually have guns in range for a first shot when emerging from stealth. Probably, this is one reason why we're not allowed to equip the Slayer cannon with it's 18,500 point alpha strike to the Vanguard chin. It would be way OP and able to one shot all small ships from stealth.
As to "emerging from stealth", it seems clear to me CIG intends stealth gameplay to concern mostly first strike scenarios, and that once you power things like thrusters, shields and weapons, your stealth is gone. The Sentinel emits 6k EM just from turning on its thrusters, and you can't aim your guns without them. Whether you have your thrusters on or off is literally
ten times as much difference in EM as whether you are using them or they're on standby. This is certainly by design. CIG wants stealth seekers to turn components off. So you really do need to think in terms of missile and weapons first strikes being very different, and you probably want to set up Voiceattack with multiple keys like "battle stations", "stealth", "superstealth", etc. There are way too many components to be switched on and off in an instant to do this manually when attacking from stealth.
Sometime in the last year, I don't recall exactly;
SC Unpacked began reporting the Vanguards have a real difference between their radar and sensor suits (scroll to bottom). So far as I'm aware, CIG has never reported they would do this, so I don't know what to make of it since sensors are not in game yet. Just FYI though, SC Unpacked says the Sentinel has S1 Ping, S2 Radar (which is cross section return sensitivity) and S1 Sensors. So far as I know this is not accurate, but the fact it's different makes me wonder if CIG isn't trying to get ready for the full EW rework we're waiting on. As of this time I don't think there has ever been a difference between ping, radar and sensors sizes on any ship. So who knows where SCUnpacked gets its data.
Hardpoint still
carries no sensor data since they don't consider it something that is in game yet.
Final BTW, I had this discussion online in another forum a year or more ago, so wanted to note--the whole notion that the Sentinel frame with the Harby torp package should make a great stealth fighter-bomber package is a complex issue. One thing to note when considering: the Harby has its beds on the port side and the Sentinel on the starboard. If the sides swap individually, you could build a stealth, EW fighter-bomber without beds. What the modularity means in the Vanguard is unresolved, but with stealth restored to the Sentinel, stealth fighter-bombers are a thing again. Even if you can't swap sides separately, putting the Harby torp package into the Sentinel frame should yield a stealth fighter-bomber with beds. It looks like CIG planned this, because the Harby is the only variant with the beds on the port side. They did extra work just for this result. If you look at the hull of the four Vanguards from outside, it appears the modules swap each side, so. . .who knows what CIG plans. A stealth fighter-bomber with 2 beds, advanced EW and no EMP sounds like what I want. Just to do Electronic Warfare right, that Rear Equipment Operator (REO) needs that ultra cool standing display to actually do something.
And speaking of doing something--easter egg for those who read all that: were you aware that the Vanguards all have an empty component bay starboard of the steps up into the cockpit? Empty, meaning there is nothing yet planned for that space, yet there is a space. Even life support has a bay on the Vanguard. There is an EMPTY equipment bay on all Vanguards. So. . .
