Flying through points in Litchi and setting up the camera for photogrammetry (tutorial)

Creating a mission in Litchi and setting up a drone camera for photogrammetric work

There are many applications that provide route creation for drones during photogrammetric work. For a number of reasons, we recommend that our students in the Aerogeodesy course use the Litchi program to build routes with the help of drones. In classes at the school of pilots of drone operators Dmitry Sledyuk, we analyze the nuances and life hacks of working with this program. The purpose of this article is to recall the sequence of actions for creating routes and setting up the drone camera for photogrammetry. In the process of creating the article, the quadcopter DJI Mavic 2 PRO was used as an example.

Route construction in Litchi.

Assignment of waypoint properties

1. Set the altitude of the flight at the first point
2. Arrange all waypoints of the drone route based on the distance between takeoffs
3. Adjust drone turning radii at waypoints within 9-12 meters

Route Properties

1. Set the direction of the drone as “Auto Setup”
2. Completion of the action: “Return home”
3. Path mode: set Radius Rotations
4. Cruising speed: around 40km/hr (recommended)
5. Maximum flight speed: set to maximum
6. Save the route.

Setting up the drone camera for photogrammetric work in the Litchi app

(We remind you that setting up the camera is only possible when the Drone is turned on and the control panel is connected to the tablet)

Setting up the exposure of the drone camera

1. Set the shooting mode “Photo”
2. In the camera settings “Exposure Settings” select the automatic aperture — mode “A”
3. Fully open the aperture
4. Set exposure correction from -0.3 to -0.7

Setting the shooting mode

1. Set the image format “JPG”
2. Set shooting mode: “Interval” and 2s shooting frequency
3. Lower the camera vertically down

Launching the drone along the route

1. Run the mission for execution with the selected route point
2. After setting the height, do not forget to start the interval shooting

Notes on the features of working with the Litchi application

DJI is constantly changing the algorithm of interaction of the drone and applications to configure and control it. In this regard, a situation is possible when after launching Litchi, the application does not see the drone. In some cases, it helps to pre-launch the DJI GO 4 program, and without closing it, to start Litchi.

We recommend using iOS-based devices to work with the Litchi application. In our experience, Litchi works more sustainably under this operating system. In addition, in IOS it is possible to switch between different applications to control the drone raid, while the Android OS each time requires changes with standard programs for the remote, as for a USB device.