Fleet Detection

Fleet Detection in Per Regna covers how commanders learn about hostile (and friendly) fleet movements: Radar Station fleet scans, early-warning push alerts for incoming attacks, incoming probe alerts, the galaxy activity dots that hint when a target is at the keyboard, and how attackers use Frigates and moon launches to stay harder to spot.

In-game help: Settings → Quick Guides (Early Warning Alerts, Radar Station, moon launches).

Notification preferences: Settings → Notifications (push) and Settings → Mail (probe mail importance).

Early-warning attack alerts

Colony-under-attack push notifications for PvP attacks do not fire when the fleet launches. The defender is warned only when the attack is in its final approach window.

Base warning: 20 minutes before arrival
Radar bonus: each level of Radar Station on moons orbiting the target world adds +1 minute (the highest radar among those moons is used)
Frigate reduction: attacker Frigate escorts shorten the window (see below)
Final window: always clamped between 10 and 30 minutes remaining

If the flight is already inside that window when it launches, the defender is notified immediately.

Pirate / PvE targets do not use this attack early-warning flow the same way — it is aimed at player colonies.

Attack and probe alerts are controlled separately in notification settings. You can keep attack warnings on while turning off incoming probe pushes.

Incoming probe alerts

When scout probes approach your colony at 30%+ speed, you can receive an Incoming Probes push. This is separate from colony-under-attack alerts.

Probe detection still creates mail. In Settings → Mail you can choose whether new probe detection reports are automatically flagged as important (they still always arrive in your inbox).

Fleet return notifications

When your fleet docks at home, a fleet-return push can fire. Under Fleet Returning in notification settings you can choose which mission types notify you.

Example: keep Attack returns and Expedition returns on, but turn off Harvest returns and Transport & collect returns so quiet logistics runs do not ping your device.

Mission report mail (harvest, transport, expedition, and so on) can still be filtered separately under Mail notifications if you have Imperial Access.

Frigate stealth

Matching Frigates to the rest of an attack fleet shortens the defender’s early-warning push:

For every 5% of other ships matched by Frigates, warning time drops by 1 minute
Maximum reduction: −20 minutes when Frigates equal or exceed the rest of the fleet
Combined with radar, the alert still never leaves the 10–30 minute band

Example: a fleet with as many Frigates as other hulls can push a low-radar defender toward the ~10 minute end of the window.

Radar Station scans

The moon-only Radar Station can run a fleet scan on an enemy or pirate planet in range (Gas cost scales with distance; range grows with level — about +1 system grid every two levels).

A successful scan can reveal fleets traveling to or launching from that planet: mission type, timing, composition, and cargo.

Fleets launched from the scanned planet stay visible on their way back: a returning fleet is listed from its mission target to the scanned planet, with its return time. Other players' fleets flying home after reaching the scanned planet are not shown; their return can only be seen from their own home planet. Distance is shown in grids, rounded to two decimals.

Radar does not see:

Your own moon
Another player’s moon base as a scan target in the same way as a planet
Targets beyond radar range
Fleets that launched from a moon (see below)

Moon launches

Fleets launched from a moon are invisible to Radar Station scans of planet activity. Radar tracks planet-tied movements; outbound moon launches do not appear on those scans.

Use moons as staging points for surprise attacks, covert transports, and timed raids. Pair with Sensor Array scouting when you need target intel without advertising your own launch.

Galaxy activity dots

Colonized planets belonging to other commanders carry a small activity dot in the galaxy view. It is a coarse "someone was here recently" signal, not a fleet scan — it says nothing about ships, resources, or defenses.

Dot	Meaning
Green	Acted within the last 15 minutes
Yellow	Acted within the last 30 minutes
Orange	Acted within the last hour
None	Nothing in the last hour

The dot marks the colony the owner actually acted on — the planet where they built, researched, queued, cancelled or scrapped ships, launched, recalled or warped a fleet, traded, ran a scan, managed buildings, the hangar or monuments, or simply switched to it — not every colony they own. Opening the game does not count as a switch, and leaving the game open on one colony does not keep it lit. A commander who is online but only browsing the map still lights the colony they worked on last, so an active player shows exactly one lit planet rather than their whole empire. Actions on a moon count for its parent planet.

Your own planets never show a dot.

Reading it. A green dot means the owner is very likely at the keyboard right now — worth weighing before committing a raid, since resources can be moved and fleets saved. An orange dot on a large colony is a softer signal. No dot means only that nothing happened there in the last hour, not that the player is gone.

Sensor Array

Sensor Array (moon) is a different tool: it scans nearby space for asteroids and pirate activity, not the attack early-warning timer. It complements Fleet Detection but does not replace Radar Station or Frigate stealth.

Fleet Detection

Fleet Detection

Contents

Early-warning attack alerts

Incoming probe alerts

Fleet return notifications

Frigate stealth

Radar Station scans

Moon launches

Galaxy activity dots

Sensor Array

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