I couldn't find any information on stealth, specifically what determines if someone can detect you when you are in stealth. I suspect it has something to do with these stealth levels that I see being referred to in the Concealment talent tree.

I can only speculate how a stealth level works but I want something more concrete so that I can decide to put points into the talents of Tier 2 Concealment tree. I'm particularly interested in the ability to detect 2 levels higher ... if I only understood what that actually meant.

My current understanding is that your stealth level is equal to your real level. If your stealth level is equal to an opponent's level, they you can hide from them, get in close and have a few seconds to attack them. If my stealth level is lower than their level, they simply aggro you at the normal aggro range. Empirically, this is how it seems to work.

Can anyone add some insight or correction to the process of stealth detection and the impact of raising your stealth level and detection?

Stealth levels make a big difference. I don't know the specifics of the math involved -- all I can say is try the talents and see, the difference should be quite noticeable. With Scouting, it's common for me to pick up stealthers 10m away. I didn't always take Scouting, until I noticed some other Ops always getting the opener on me.

Also, Scouting provides a +1%/+2% bonus to Force and Tech resistance (despite the tooltip saying Defense), which isn't a game-changer, but it's a nice bonus on a talent already worth having.

Apears to be a radius of detection over time in detection zone 180 degree observers frontal arc, compared to observers stealth detection level to your stealth level. AKA common MMO stealth system.

People running up behind you generally have enough time in the detection zone to see you regardless of talents you've taken. Untalented people running past you while you are moving towards them often see you and adjust. Talented if you keep a bit of space you tend to have time. The 60 second CD helps alot in remaining undetected.

No scientific testing just plenty of usage went into the formulating of this opinion.