Coordinate Frames

PolySync sensor nodes can be configured to specify the active coordinate frame through the use of parameters. All PolySync provided dynamic driver interfaces support this parameter through the [Transform API](http://docs.polysync.io/#c-transform180). ### Setting the active coordinate frame Parameter ID `800` is the `active coordinate frame identifier`─which correlates to the values below─and is found in the SDF Configurator **Node Configuration** section. PolySync provides some commonly used coordinate frame systems used in autonomous vehicles, and custom coordinate frames can be defined for use in a node. #### 0. Invalid This coordinate frame should not be trusted or referenced. #### 1. Unknown The originating node is unable to determine the coordinate frame identifier. #### 2. Not available Coordinate frame not available. This is typically used for nodes that don't have, or don't need, a coordinate frame. #### 3. Local (sensor) Standard right-handed PolySync local coordinate frame, also known as the vehicle coordinate frame. #### 4. Platform Standard right-handed PolySync platform coordinate frame. Fixed in the platform body, i.e. a fixed body coordinate system. This is the **default configuration** for dynamic driver interfaces. A PolySync vehicle's coordinates conform to ISO8855:1991 and SAE J670:JAN2008, and follow the conventions shown below. Axis and angle of rotation are right handed. For the Vehicle Centered Reference Coordinate Frame (VCRF), the origin is the **center of the rear axle on the ground**. ![Right Handed Coordinate Frame](https://help.polysync.io/releases/2.0.8//wp-content/uploads/2016/09/GW500H283.jpeg) #### 5. Relative Standard right-handed PolySync relative coordinate frame. Typically based on a dead-reckoned navigation solution. #### 6. Absolute Standard right-handed PolySync absolute coordinate frame. Typically based on an absolute or world navigation solution like the WGS84 UTM coordinate frame in a given zone.