Daylight object in close proximity to Sky Harbor AirportI was operating a sound system (mics and speakers) for the groundbreaking of a new Valley Metro light rail station at 50th St. and Washington in Phoenix, serving the Ability 360 Center. This location is almost exactly one mile from the eastern end of the north runway at Phoenix Sky Harbor Airport, runway 26. The event was taking place on the roof of the three story facility. There is a shade structure running along the north and west portions of the roof. A 20'x20' canopy had been erected to provide shade for the guests. My position was near the northeast corner of the roof where I had a small audio mixing board set up. At that time aircraft were departing Sky Harbor to the east, from the north runway, passing less than a half-mile from my position. The event had begun at 8am with the Phoenix Mayor discussing details of the project. At 8:20am, I noticed an object come into my field of view from the north, just above the Mayor's position at the podium, at a bearing of about 310 degrees. It was elongated in the horizontal direction, reflective or very light in color. I could not judge distance, but felt that it might be about a mile away, based on having witnessed countless aircraft approaching Sky Harbor. I appeared to be similar in size to a small FedEx single engine turboprop aircraft which utilize Sky Harbor. Its altitude was lower than that of an aircraft crossing over, so I immediately assumed it was making an approach, but it should have been much further west if that were the case. I could not detect any vertical structure such as a tail, the reflective brilliance made it difficult to make out details. It continued south for a short distance then suddenly either came to a complete stop or made an immediate “jog” toward the west. At this point the idea of “drone” popped into my mind, but the apparent distance to the object made it questionable if a drone would be that visible. The other reason to reject the drone theory was the proximity to Sky Harbor. The object then continued making a fairly rapid arc toward the southeast, again with an immediate acceleration which seemed very “drone like.” I lost sight of it behind the canopy until it emerged southwest of my position. It appeared to be following the departure path of runway 25, the center runway, toward the east, but more rapidly than a traditional aircraft. I continued to observe it for another 10 seconds until it moved behind a large structure on the roof. I moved to the other side of the structure but I did not see the object again. I could not detect any noise from the object, at least nothing which I could hear above the traffic on Washington Street and the PA system I was operating. The movement was unlike normal aircraft in the sudden acceleration and deceleration. The object's altitude seemed constant. Based on the flight path I observed I would dismiss any thought of it being an actual drone. My immediate reaction was thinking “how bold” to venture into the departure path of Sky Harbor in broad daylight. I have almost 40 years of working in close proximity to Sky Harbor Airport and am very familiar with aircraft and aircraft operations. This object did not operate by normal flight standards.