kzt wrote:You mean if you are inside the beam of a cruiser scale graser? Because that’s the only signal that doesn’t follow inverse square law. Is that what you are saying?
The beam itself won't follow an inverse square law because it's a laser. And if you're in its path, you're not telling a story.
But all of its effects and side-effects around it will. I can think of at least three things to measure that don't require being within hair-width distance of a graser beam. First and most obvious is the energy transferred to the target. Manticore knew exactly the composition of its space stations, so it's reasonable to calculate how much energy is required to produce the explosions that were observed. The energy dispersal is also correlated with the amount of energy delivered per unit of time and area on target, so scans of the target prior to saturation of the sensors should give you some idea too.
Second, the space dust and solar wind excited by the passage of the beam. The Interplanetary medium is not a vacuum and at the energy levels of the gamma-ray beam, it will cause space to glow like a laser pointer on cigarette smoke, just maybe not on visible light spectrum. The beam is not perfect either (it would have infinite range if it were), so detectors downrange of but not in the path of the beam will detect leakage. Especially if the beam itself was occluded by the space station.
Third, the torpedo's own self-immolation. This is especially interesting, because the RMN has very good data (probably the best data anywhere) on how missile bodies behave and what they emit when firing a laserhead. That thing is a very bright source. And because the torpedo must be very efficient but not perfect, that means most of its energy went into the beam, but some of it leaked out in all other directions. And because the RMN has extensive expertise on grasers, they can compare their data with these torpedoes and make lots of inferences. Moreover, they can do the same to the Galton graserheads, for which they'll have far more data on including some actual specs and samples, which will allow them to conclude those aren't the same and, hopefully, were less advanced/powerful than what attacked during OB.
At a minimum, we know the GTs were 3-second grasers, while the Galton ones weren't. The time a laser is firing is very easy to tell. And I think this is likely the single greatest contributor to energy. I could give you that telling the power of the laser is difficult because of saturation, but energy is power multiplied by time. Since you have the value of time with very good accuracy and you have a lower bound number for power because that's the threshold of saturation, you have the lower bound of energy.