In the other comment achille links to a Frontline description of how a similar system was used in Iraq. The 20,000 foot system with poor resolution was used to

In the other comment achille links to a Frontline description of how a similar system was used in Iraq. The 20,000 foot system with poor resolution was used to continually track an area, when something suspect occurred they would send in a higher resolution Predator and then if it checked out further they would follow and target the people on the ground.