Sensor fingerprints for space objects

This is an idea from playing too much Allegiance and UFO Afterlight, and from working with real radar&lidar systems.

The sensors system is quite naïve: a spaceObject is either seen or not seen, and "sensors" is just one monolithic system. In real life, targets are acquired by aggregating input from several sensor systems: radar, lidar, AIS, FoF, cameras, and what-have-you.

Also, some objects (e.g. planets, stations) are more difficult to detect than others (fighter ships). This is the sensor fingerprint.

I don't want to reinvent the Science UI but rather set foundations for this.

So every space object should have several attributes:

• Mass, measured in tons. Massive objects will show up in gravimetric sensors (and, yes, gravimetry is a real thing https://en.wikipedia.org/wiki/Gravimetry ).
• Reflectivity, measured in percent. AKA "if I throw some radiation at the thing, how much will I get back?". Rough surfaces (planets) have high reflectivity, and stealth ships have low reflectivity. Active sensors (such as radar) operate under this concept.
• Radiance, measured in watts. AKA "how much energy is the thing passively emitting away". Shielded spaceships should have low radiance. Things like warping and firing beams would momentarily increase radiance. Passive sensors (such as video cameras) operate under this concept.
• Psi, AKA "intelligent lifeforms", measured in sapiens (1 sapien = the brain of a standard homo sapiens). Futuristic alien sensors might be able to detect Psi, because UFO Afterlife had "Psi Vision" http://www.ufo-afterlight.com/images/scr_10.jpg . And maybe some aliens are attracted/repelled by Psi.

If we want to go crazy, radiance and reflectivity can be split into several parts of the EM spectrum: microwave, visible and x-ray.

I just want my science officer to yell "Contacts in the gravimetric sensor, activating microwave emitters!" :-)

The issue names the monolithic “sensors” system and spaceObject as starting points, but no files or tests. First trace those entry points and determine how the proposed mass, reflectivity, radiance, and Psi attributes should support sensor aggregation; done requires an agreed foundation without redesigning the Science UI.