As an adjective, just a place filler, as, "You Know," or, "The thing of it is... " Usually an attempt to give extra impact to a statement.
"There are serious problems on the ground." Meaning, There are serious problems (there).
The opposite of a bird's eye view--describes a situation viewed up close or the people in a position to view a situation up close, in detail. Typically used by someone at a level of remove from the situation being discussed. George Bush uses this phrase frequently to describe the situation in Iraq or the troops in Iraq--i.e., to refer to the reality, with which he is only faintly acquainted.
the situation on the ground
the troops on the ground
Far off in Washington or at best confined to the Baghdad Green Zone, the American leadership had only a vague knowledge of the actual situation on the ground, so the extent of sectarian violence caught them by surprise and completely ruined their luftslott dreams of democratizing the Middle East by deposing Saddam.