# Doppler Motion Tracking Mode

Here we will add some more in depth content, but for now see [The Doppler Motion Tracking Blog Post](https://blog.ceruleansonar.com/introducing-doppler-motion-tracking-on-omniscan/).

### Ardupilot Parameters

Note: Some firmware versions may be missing parameters from this list. 

| Parameter        | Value       |
| ---------------- | ----------- |
| EK3\_ENABLE      | Enabled     |
| EK2\_ENABLE      | Disabled    |
| AHRS\_EKF\_TYPE  | Enable EKF3 |
| VISO\_TYPE       | MAVLink     |
| GPS\_TYPE        | AUTO        |
| EK3\_SRC1\_POSXY | ExternalNav |
| EK3\_SRC1\_VELXY | ExternalNav |
| EK3\_SRC1\_POSZ  | Baro        |

### Suggested Starting PIDs

These values were tested on a BlueROV2 Heavy. The objective is to achieve smooth and predictable motion. Different vehicles and use-cases will require different tuning values. 

| Parameter           | Value |
| ------------------- | ----- |
| PSC\_POSXY\_P       | 0.6   |
| PSC\_POSZ\_P        | 1.0   |
| PSC\_VELXY\_D       | 0.2   |
| PSC\_VELXY\_I       | 0.02  |
| PSC\_VELXY\_P       | 4.0   |
| PSC\_VELZ\_P        | 5.0   |
| ACRO\_YAW\_P        | 4     |
| ATC\_RAT\_YAW\_FLTE | 5     |