Bruce Alan Macintosh's definative sensor rules for T4 (required for T4's fire, fusion and steel 2). Reproduced here inline with his permission guidelines found at http://traveller.mu.org/house/sensor.rules.html - This is an absolute gem of a system.
The shattered Imperium, the Rebellion Era, the death pains of an entire civilisation, complemented with a major revision of the original Traveller Rules - one of the best and most optimal rule sets to date for Traveller.
MegaTraveller