If you look under the engineering room's status display of a ship equipped with a long-range travel system, you will see its long-range point of interest sensors listed. These are the systems which can detect nebulae, star systems, and other unusual sites as you travel.
These sensors work by continuously analyzing the space through which the ship is traveling. If the computer decides an area is anomalous or otherwise may be of interest, it adds a designation to the target and pings the crew. How reliably a ship can identify these areas depends on its sensor class. Its sensor class also determines the range at which it can detect things, though this is also affected by model, aftermarket upgrades, and other considerations.
There are five sensor classes:
Standard: These detect all potential points of interest at the standard range.
Warship-Grade: These sensors are optimized for close-in, fast-moving targets, and tend to be worse at locating points of interest while exploring, detecting fewer and at shorter ranges.
Exploration-Grade: These sensors are above-average at detecting new areas and detect at an extended range.
Expedition-Grade: Like exploration-grade, but a further step up.
Utility-Grade: A standard detection range, but these ships are optimized for specific niches and dedicate no time toward analyzing anomalous areas. If they detect anything at all, it is likely to be only large debris clouds in the forms of nebulae, Opik-Oort signatures, and the like. (Note: Rift-linking ships with utility-grade sensors will downgrade a flotilla's find rate and quality.)
Your sensors are also given a percentage rating, where 100% represents a standard unmodified example model of its sensor class.
