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The Low Frequency Locator (LFL) , is a prototype device , used to scan a ship's surroundings for very low frequency signal emissions. It is able to detect these signals at extremely long range, but this does affect its accuracy. When enabled, the ship's HUD will show a pointer that approximately indicates the signal's direction of origin. It is an a useful tool to help find items that may be scattered around the galaxy, such as derelict ships or floating crates containing wares. Most importantly, however, it is the only means to identify a Hyperspeed Access Point (HSAP). An HSAP may, in turn, provide access to parts of systems that are otherwise inaccessible; these areas are colloquially referred to as Remote System Locations (RSL). The LFL can lead to lucrative discoveries; not only by locating objects, but also for the Discovery Point values those locations represent, which can be turned in at the Explorers Guild for valuable rewards.
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While activated, it will only show the UI if there is something discoverable in range, but it can be manually turned off. To do this you will have to assign a hotkey in the ingame Options under "Controls -> Game -> Targeting -> Toggle LFL Mode".
The LFL will pick anything sector wide, then at 20km will show the middle level as filled and at 5km thats in range, then once <playership> reaches <20km range the middle bar is filled, and at <5km range it will fill the top level. Once closer than 1500m, the discovery triggers and the object is considered discovered. Discovery points are then rewarded and added to the total and current pool.
The range of the LFL various depending on the object and sector, some things like the HSAP are sector wide, other things like ware crates/ships can have a limited range so the LFL might not trigger straight away upon entering the sector. However, generally you shouldn't need to go beyond the borders of the sector before the LFL will trigger if there is anything in the sector.