# Retrieve.kdp\_maesake unexpected output problem with Py-ART

**URL:** <https://openradar.discourse.group/t/retrieve-kdp-maesake-unexpected-output-problem-with-py-art/527>\
**Category:** Python\
**Tags:** py-art, data, pyart\
**Created:** [October 31, 2024, 8:52am UTC](https://openradar.discourse.group/t/retrieve-kdp-maesake-unexpected-output-problem-with-py-art/527 "2024-10-31T08:52:39Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Woutv](https://avatars.discourse-cdn.com/v4/letter/w/aca169/32.png) [@Woutv](https://openradar.discourse.group/u/Woutv)\
**Post date:** [October 31, 2024, 8:52am UTC](https://openradar.discourse.group/t/retrieve-kdp-maesake-unexpected-output-problem-with-py-art/527/1 "2024-10-31T08:52:40Z")

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Hello

I am trying to create KDP values from PhiDP values from a Radar. The radardata I can extract are .VOL files will not be compatible with Py-ART. So I wrote a code to transform the file structure so that it can be stored as a Py-ART radar object construction. I think I do that right because when opening the file, the data is present. Now when I run the pyart.retrieve.kdp\_maesaka funstion, the KDP outcome is everywhere 0.002.

 ![image](https://global.discourse-cdn.com/free1/uploads/openradar/original/1X/be1ddde390fa44a078fb6be4adca294647550e56.png)

What could be the problem and how could it be fixed?  
Thanks for the help  
Wout

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**Author:** ![RicardoRadar](https://avatars.discourse-cdn.com/v4/letter/r/3e96dc/32.png) [@RicardoRadar](https://openradar.discourse.group/u/RicardoRadar)\
**Post date:** [November 6, 2024, 12:50pm UTC](https://openradar.discourse.group/t/retrieve-kdp-maesake-unexpected-output-problem-with-py-art/527/2 "2024-11-06T12:50:32Z")

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Hi Wout, a related question: do you know if the routine pyart.retrieve.kdp\_maesaka takes care of phase folding? or do we need to correct it beforehand?

Ricardo

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**Author:** ![mgrover1](https://yyz2.discourse-cdn.com/free1/user_avatar/openradar.discourse.group/mgrover1/32/7_2.png) [@mgrover1](https://openradar.discourse.group/u/mgrover1)\
**Post date:** [November 11, 2024, 3:45pm UTC](https://openradar.discourse.group/t/retrieve-kdp-maesake-unexpected-output-problem-with-py-art/527/3 "2024-11-11T15:45:48Z")

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> [@Woutv](#):
>
> So I wrote a code to transform the file structure so that it can be stored as a Py-ART radar object construction. I think I do that right because when opening the file, the data is present. Now when I run the pyart.retrieve.kdp\_maesaka funstion, the KDP outcome is everywhere 0.002.

You likely need to unfold the PhiDP first, I would recommend trying that