# Pioneer Glider behavior

**URL:** <https://discourse.oceanobservatories.org/t/pioneer-glider-behavior/691>\
**Category:** HelpDesk\
**Created:** [October 10, 2023, 5:41pm UTC](https://discourse.oceanobservatories.org/t/pioneer-glider-behavior/691 "2023-10-10T17:41:00Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![rvaillancourt](https://avatars.discourse-cdn.com/v4/letter/r/c77e96/32.png) [@rvaillancourt](https://discourse.oceanobservatories.org/u/rvaillancourt)\
**Post date:** [October 10, 2023, 5:41pm UTC](https://discourse.oceanobservatories.org/t/pioneer-glider-behavior/691/1 "2023-10-10T17:41:00Z")

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Is there a set depth from the bottom the PA gliders will descend to? I think they use sonar to detect the bottom and then turn upward, but I can’t find anywhere what that distance is.

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**Author:** ![cdobson](https://avatars.discourse-cdn.com/v4/letter/c/da6949/32.png) [@cdobson](https://discourse.oceanobservatories.org/u/cdobson)\
**Post date:** [October 11, 2023, 1:00pm UTC](https://discourse.oceanobservatories.org/t/pioneer-glider-behavior/691/2 "2023-10-11T13:00:51Z")

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Hi Robert,

Yes the gliders use an altimeter to detect the bottom and inflect. It has likely varied over the years but at Pioneer we typically try to inflect between 10 and 20m above the bottom. There is usually some variance involved in this because the pump types differ in how long they take to inflect.

Take care,  
Collin

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**Author:** ![cdobson](https://avatars.discourse-cdn.com/v4/letter/c/da6949/32.png) [@cdobson](https://discourse.oceanobservatories.org/u/cdobson)\
**Post date:** [October 11, 2023, 1:24pm UTC](https://discourse.oceanobservatories.org/t/pioneer-glider-behavior/691/3 "2023-10-11T13:24:05Z")

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Robert,

I wanted to follow up and let you know that the glider does record altitude data and it is available in the recovered files. If you were looking at the raw data files it would be parameter m\_altitude.

This data is also available for recovered glider datasets ingested into OOINet under the glider\_eng\_recovered stream.

Take care,  
Collin