` decimal(10,0) NOT NULL, KEY `index1` (`pigeon_id`,`pigeon_station, pigeon_station from pigeon_signal group by pigeon_id, pigeon_station) ps2
on ps.date_time = ps2.date_timeand ps.pige
var lastUpdateTime: TimeInterval = 0 let pigeon: Pigeon = Pigeon() let ground: SKSpriteNode = SKSpriteNode(imageNamed: "Road")//crashes if camera and pigeon do not exist