The link between the smartphone and the drone is handled by the bundled "G-Box" transmitter, which gives a 0.6-mile or 966-meter radius range. To satisfy the more capable drone users, Ehang is already developing a proprietary 8-channel remote controller for the Ghost. Yes, "proprietary" in the sense that the drone won't work with existing controllers, in order "to enhance steering safety and smooth manual control."
As for the auto-follow mode, don't expect the drone to follow you while you're climbing up a cliff; it can only travel horizontally so use with caution. That said, Xiong hasn't ruled out the possibility of adding auto-altitude control as more phones come with a built-in barometer. Unlike the Plexidrone due in April, the Ghost doesn't do obstacle avoidance which is no surprise given its price point, but as you can see in the above video, there's work being done on a LIDAR module that may one day allow this drone to detect its surroundings. Until then, the auto-follow feature is best used in a clear area.
Now that we've gotten the features out of the way, we can take a closer look at the drone itself. The Ghost can travel at up to 21.9 m/s, though it's capped at 4.47 m/s by default for safety reasons (for the record, the DJI Phantom 2 does 15 m/s max). Ehang claims that its machine can even fly in winds at up to 21 knots (about 11 m/s) without losing too much video quality, and it can also resist light rain. The interchangeable 5,400 mAh battery can last up to 20 minutes with the optional 2-D gimbal plus a GoPro camera installed, or up to 30 minutes without them (the Phantom 2 does 25 minutes).
For the last option, there's actually no harm in considering the Phantom 2 Vision which is now only $799 (or $899 with an extra battery) and also has a two-axis camera, a traditional controller plus video stream capability to your smartphone. On the other hand, if you want to go beyond 1080p video capture while also having the option to reuse the Hero4 Silver on your next drone, then the Ghost would be a safer bet.
source: engadget.com by Richard Lai