Keep in mind that the elevation reportedby the DJI Go is relative to your launch elevation, which is set at 0 by the barometer during warmup. If you are launching to 400 feet from a launch site at 250 above sea level, and maintaining that altitude when flying over sea level, you are actually 650 feet above sea level, which really helps with the range! I've reached 2.73 miles before the video got sketchy! Elevation is your friend. On the other hand, even a single tree on the ground anywhere directly between you and your aircraft can drastically reduce the range, so try and position yourself above your subject at launch with a clear and continuous LOS, to avoid any signal interruption.