It looks like a Castle Air (or similar) charter helicoper with an equipment package "bolted-on". The 2 aerials on each side of the helicopter look like survey grade GPS receivers to me. I cannot see whats in the tray under the fuselage but I would guess at cameras or other sensors. Either way for what it's worth I would say it was doing a survey of some kind.
Definitely not a Castle Air ....... might be Gas pipeline survey ?