User manual

Aircraft
Phantom 4 User Manual
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2017 DJI All Rights Reserved.
25
Detection Range
The detection range of the Obstacle Sensing and Vision Positioning System is depicted as follow. Note
that the aircraft cannot sense and avoid the obstacles that are not within the detection range.
Obstacle and Vision Positioning System
The Phantom 4 is equipped with an Obstacle Sensing System that constantly scans for obstacles in front
of it, allowing it to avoid collisions by going around, over or hovering. The DJI Vision Positioning System
uses ultrasound and image data to help the aircraft maintain its current position. With the help of Vision
Positioning, your Phantom 4 can hover in place more precisely and fly indoors or in other environments
where a GPS signal is not available. The main components of the Vision Positioning System are located on
the bottom of your Phantom 4; they include [3] two ultrasonic sensors and [1] [2] four monocular sensors.
When you turn on the aircraft, the vision system will record the flight environment and will store its vision
system image data in the flight data record system. Vision system image data is used to improve the
performance of positioning reliability and accuracy by matching it to current real-time environments.
[1]
[2]
[3]
It is important that you only fly in conditions where the Vision Position System can function
correctly; otherwise the Terrain Follow Mode will not work.
Only use Tripod Mode where the GPS signal is strong or light conditions are ideal for the vision
system. If GPS signal is lost and the vision system cannot function, it will automatically switch
to Atti mode. In this case, ight speed will increase and the aircraft cannot hover in place. Use
Tripod Mode carefully.
Terrain Follow Mode
The Downward Vision System is utilized in Terrain Follow Mode to maintain a height above ground
between 1 and 10 meters. This mode is designed for use on grassland sloped at no more than 20°.
Enable the Terrain Follow Mode by tapping the Intelligent Flight Mode icon in the DJI GO 4 app.
When this mode is enabled, the aircraft’s current height will be recorded. The aircraft will maintain
the recorded height during ight and ascend when the slope rises. However, the aircraft will not
descend in downward slopes.