Detect that lets you see your target?

[Refplace]

Originally Posted by awesomenessofme1

The question isn't about detecting and targeting, it's about being able to ignore the normal penalties for attacks and defenses against someone who you know the exact hex location of, but can't see.

Precise lets you do that, thats why its such a major modifier.
Enhanced Senses even has a Precise version of Hearing as an example.

Precise senses have the capabilities of basic senses and can
determine the distance to a target, allowing an aimed ranged
attack. They are always ranged. Examples: Active IR; Detect
(Precise); Imaging Radar; Ladar; Megahertz Sonar; Para-Ra-
dar; Radar; Sonar; T-Ray Vision; Vibration Sense; vision.

Targeting senses have the capabilities of precise senses and
can determine a target’s exact range and speed, giving +3 to
hit with an aimed ranged attack. This option narrows your arc
of perception – you perceive the object normally, and 30° to
each side at -2. Examples: Radar (Targeting); Sonar (Target-
ing); Vibration Sense (Targeting).

Note that Targeting is a limitation that adds speed detection but narrows the spotting area to that of regular vision.
Both of these are in Powers but Enhanced Senses adds more detail.

[Anthony]

Originally Posted by Toptomcat

And these people can be 'sensed and targeted' for *all* purposes as if they were being seen? For instance, would either of these two constructions permit an unpenalized defense against a melee attack by a powered person in a side or rear hex?

Assuming the attack was visible, yes (it might not be fully effective if the powered person used a mundane weapon, as the weapon would be invisible).

[Anaraxes]

Originally Posted by awesomenessofme1

someone who you know the exact hex location of, but can't see.

"See", in more technical jargon, doesn't mean only vision, but means a Precise sense. Vision is the only Precise sense normal humans have, so the Basic rules often use words like "see" when they really mean "any Precise sense". But then, they didn't have such a formalized hierarchy when Basic came out.

The arc in which a sense operates is a separate question. Vision normally isn't all-around; hence 360-Degree Vision. Detect, on the other hand, normally has a 360 degree arc. If you wanted to give it the same arc as normal human vision, you'd add a Limitation to the sense. (GURPS defaults to normal human behavior as its 0-point baseline. It doesn't built everything up from nothing as 0 points. So, different features can have different starting points.) You could have a Vague or Nondirectional sense that was still 360, or a Precise sense that isn't.