# Position hold using USBL

**URL:** <https://discuss.bluerobotics.com/t/position-hold-using-usbl/3786>\
**Category:** Blue Robotics Software\
**Tags:** positioning\
**Created:** [November 23, 2018, 5:57pm UTC](https://discuss.bluerobotics.com/t/position-hold-using-usbl/3786 "2018-11-23T17:57:47Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![rnr](https://avatars.discourse-cdn.com/v4/letter/r/ac91a4/32.png) [@rnr](https://discuss.bluerobotics.com/u/rnr)\
**Post date:** [November 23, 2018, 5:57pm UTC](https://discuss.bluerobotics.com/t/position-hold-using-usbl/3786/1 "2018-11-23T17:57:47Z")

</div>

Hi,  
How do we enter into the position hold mode using the USBL System?  
I have a Waterlinked system that gives me positioning under water.  
I was hoping to achieve the same level of position hold as exhibited by BlueROV2 in the demo video released by Bluerobotics when launching the USBL system.

-Rahul

---

<div class="post-metadata">

**Author:** ![patrickelectric](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/patrickelectric/32/2162_2.png) [@patrickelectric](https://discuss.bluerobotics.com/u/patrickelectric)\
**Post date:** [November 26, 2018, 11:19am UTC](https://discuss.bluerobotics.com/t/position-hold-using-usbl/3786/2 "2018-11-26T11:19:14Z")

</div>

Hi,

You can select the position hold mode via QGC mode menu:  
 ![image](https://us1.discourse-cdn.com/flex019/uploads/bluerobotics/original/2X/6/6ccfe1a044f5c2f4b476300e3eb90af9af9fc664.png)

or with a configurated joystick button:  
 ![image](https://us1.discourse-cdn.com/flex019/uploads/bluerobotics/original/2X/0/01d3e25033986558893a9a23d3ff39e57afa3cec.png)

> Note: Position hold is not considered stable.

---

<div class="post-metadata">

**Author:** ![k-deboer](https://avatars.discourse-cdn.com/v4/letter/k/e8c25b/32.png) [@k-deboer](https://discuss.bluerobotics.com/u/k-deboer)\
**Post date:** [September 7, 2020, 5:34pm UTC](https://discuss.bluerobotics.com/t/position-hold-using-usbl/3786/3 "2020-09-07T17:34:05Z")

</div>

Hi Patrick,

I’m running:  
QGC:4.0.8  
ARDUSUB:4.01  
Companion:0.0.21

Position Hold doesn’t seem to take when selected with the drop down. The vehicle is receiving forwarded location information, and 2D GPS is selected in the parameters. QGC displays the vehicle in the map window, and Lat/Long values are displayed in the values window.

I understand that this, like some other position-based functions are not considered stable. However, is there a way to unlock them for testing?

---

<div class="post-metadata">

**Author:** ![williangalvani](https://avatars.discourse-cdn.com/v4/letter/w/6f9a4e/32.png) [@williangalvani](https://discuss.bluerobotics.com/u/williangalvani)\
**Post date:** [September 8, 2020, 5:21pm UTC](https://discuss.bluerobotics.com/t/position-hold-using-usbl/3786/4 "2020-09-08T17:21:02Z")

</div>

> [@k-deboer](#):
>
> GPS is selected in the parameters. QGC displays the vehicle in the map window, and Lat/Long values are dis

Hi @k-deboer,

Do you happen to have the dataflash logs of the last time you tried it?  
I assume the EKF was not happy with your positioning data, but a log would help to analyze what happened.

---

<div class="post-metadata">

**Author:** ![k-deboer](https://avatars.discourse-cdn.com/v4/letter/k/e8c25b/32.png) [@k-deboer](https://discuss.bluerobotics.com/u/k-deboer)\
**Post date:** [September 8, 2020, 9:31pm UTC](https://discuss.bluerobotics.com/t/position-hold-using-usbl/3786/5 "2020-09-08T21:31:35Z")

</div>

Thanks,

Here is the dataflash log. Hopefully this helps  
[log\_0\_UnknownDate.bin](https://discuss.bluerobotics.com/uploads/short-url/tW8OKz2C1XR0yzoPvI6j8Adw0e2.bin) (1.6 MB)  
The other interesting thing is the old dataflash files had dates tagged to the files. They no longer do. This started as of the last updates.