High above the grassy parkland on Randall's Island—site of this weekend's Electric Zoo music festival—hangs a robotic camera so powerful it can read text on a note pad 80 feet below.

Security officials will monitor the video feed from the camera and 11 more like it from a command center nearby, part of a new strategy during the three-day music fair to keep drugs off the island.

The Electric Zoo's return this year marks an attempt to come back from tragedy. Last year, two young people died of drug-related causes at the event, and organizers had to shut it down early. The city approved the permit for this year's event only after months of negotiations over improved safety protocols, especially stronger efforts to keep drugs out. The festival begins today and ends Sunday.

For the first time, six drug-sniffing dogs will be used amid the lines of people entering. Once again, attendees will undergo airport-style searches as they line up. Prohibited items will include open cigarette packets, glow sticks and deodorant.

Medical personnel will be posted at the entrance. They will watch for slurred speech, dilated pupils and any unusual behavior, hoping to keep out anyone who is under the influence of drugs.