I suggest a new ship stat called “concealment” or “stealth”.
This new stat would be related to the class of ship instead of any other factor. Stealth would cancel out a certain amount of enemy sensor range for the user, and also increase the chance of falling off of the enemy radar randomly or when passing behind obstacles. The bigger the ship, the lower the stealth stat, but it can be increased. From 0-150, the stat acts like a percentage of radar cancellation. (A maximum of 80% cancellation.)
I suggest that the stealth stat (from highest to lowest) should be close to as follows:
Recon - 85pts
Covert Ops - 70pts
Long-Range Frigate - 60pts
Tackler - 55pts
Command - 40pts
ECM - 25pts
Engineer - 15pts
Gunship - 10pts
Guard - 0pts
Destroyer - -15pts
With this stat, there should also be special modules used to increase it.
Name: Chameleon Shielding
Type: Passive Module (any slot)
Tooltip: (At Mk4) Increases concealment by 10 points.
Name: Radar Mask
Type: Recon Active Module
Recharge: 25s (starts once effect wears off)
Tooltip: Increases your concealment by 50 points for 15 seconds.
Name: Area Stealth Generator
Type: Command Active Module
Maximum range: 3,500m
Tooltip: Passive mode increases concealment of nearby ships by 10pts. Active mode increases the concealment of nearby ships by 35 points for 10 seconds.