Overview

Applications that wish to communicate with each other must agree on how they format and package the data they send and receive. MAVLink is one such communication protocol used for drones and other RC vehicles, providing access to telemetry data on the ground as well as allowing commands to be sent to the vehicle.

MAVLink message list and definitions:

• https://mavlink.io/en/messages/common.html

• https://mavlink.io/en/messages/ardupilotmega.html

Reference frame

Global

Latitude and longitude: The origin is at the intersection of the Earth’s prime meridian and equator.

Altitude: The origin is at mean sea level.

Relative

North and east: The origin is at the drone’s home location.

Altitude: The origin is at the drone’s home location.

• Positive is away from the centre of the Earth, negative towards. This is opposite of NED: Unit and Coordinate Conventions