Solar systems with high electricity consumption will send out emissions that can be detected by cities in other solar systems. The strength of the emissions is affected by the total amount of electricity used by all cities and spacecraft in the solar system.
A city's chance of detecting emissions from other solar systems depends on the city's deep space sensor range defined by the radar and the strength of the emissions.
Solar systems produce emissions when cities and spacecraft consume electricity. The higher the solar system's total power consumption is, the higher the emission strength and thus the further away the solar system can be detected from.
Underwater cities emit 1/10th the city's normal emission output thanks to the insulation caused by the water.
Emissions Detection Range
The maximum range of emission detection depends on the furthest deep space sensor range of any airport radar or military radar.
Any solar system outside this range cannot be detected, no matter how high the emission output of the solar system is.
Spacecraft Sensors
A spacecraft with sensor will also detect emissions from nearby solar systems, but the spacecraft will have to remain in the same solar system for about 6 hours for all possible emissions to be detected.
Light Lag
The emissions are affected by light lag, meaning that they travel at lightspeed. The further away the emission source is, the longer it takes for the emissions to be visible by the detector.
The average light lag for emissions is just a few hours.
Star map now shows a yellow glow around unexplored solar systems from which city emissions have been detected.
Solar systems emit a signal based on the hourly consumption of power by all cities in the system. The strength of this signal determines the maximum distance at which the system can be detected.
Cities with sensors detect the signal emitted by solar systems. Detection range of cities is 10pc per sensor tech level. City sensor tech level is the highest tech level of the airport terminal and anybases.
Detected solar systems are remembered for up to 48 hours after the last signal is detected from that system.
This information accumulates as the servers run. It may take an hour or two after the servers start before you start detecting city emissions. This will always be the case as this information is not stored.
Empires were reported to be too vulnerable to raiders based in the void. There is no way to know where the raiders came from or went.
System emissions are based on power consumed in a system. Power consumed by ships is now added to that signal; previously the signal was only based on power consumed by cities.
This is a step toward solving the problem, not expected to eliminate the problem. I am still considering other steps.
The emission and detection information resulting from power usage in solar systems is not saved between server restarts. It takes a long time to accumulate.
Emission and detection information is now saved and restored between server restarts.
This also flushed out a minor bug that caused solar systems to be updated to the client at times when no update was needed.