Complex Difficulty (Lowest to Highest)

Burrow / Drone Collection (lowest)
Hideaway / Drone Cluster
Refuge / Drone Gathering
Den / Drone Gathering
Yard / Drone Surveillance
Rally Point / Drone Menagerie
Port / Drone Herd
Hub / Drone Squad
Haven / Drone Patrol (est. 26 Mil)
Sanctum / Drone Horde (hardest) (est. 36 Mil)

UNKNOWN: Combat sites
GRAVIMETRIC: Hidden asteroid belts
MAGNETOMETRIC: Archaeology/Salvage (Analyzer/Salvager)
RADAR: Hacking (Code Breaker)
LADAR: Gas Cloud (Gas cloud harvester)

Radar - Amarr - white noise
Grav - Caldari - spacial
Mag - Gallente - ion
Ladar - Minmitar - phase