# \#pydda **URL:** https://openradar.discourse.group/tag/pydda/10.md [Latest](https://openradar.discourse.group/latest.md) · [Categories](https://openradar.discourse.group/categories.md) · [Tags](https://openradar.discourse.group/tags.md) --- ## [Example of Nested PyDDA Retrieval and Domain Configuration: pydda.retrieval.get\_dd\_wind\_field\_nested](https://openradar.discourse.group/t/example-of-nested-pydda-retrieval-and-domain-configuration-pydda-retrieval-get-dd-wind-field-nested/670)
**Author:** [@imd](https://openradar.discourse.group/u/imd)\ **Replies:** 0\ **Last updated:** [March 28, 2026, 8:52pm UTC](https://openradar.discourse.group/t/example-of-nested-pydda-retrieval-and-domain-configuration-pydda-retrieval-get-dd-wind-field-nested/670 "2026-03-28T20:52:14Z")
I would like to implement a nested domain approach. I came across the function pydda.retrieval.get\_dd\_wind\_field\_nested, but I would appreciate it if you could kindly provide a simple working example demonstrating how to… --- ## [Clarification on Choosing Master Radar and Grid Origin in PyDDA Dual-Doppler Retrievals](https://openradar.discourse.group/t/clarification-on-choosing-master-radar-and-grid-origin-in-pydda-dual-doppler-retrievals/650)
**Author:** [@imd](https://openradar.discourse.group/u/imd)\ **Replies:** 5\ **Last updated:** [November 25, 2025, 6:58pm UTC](https://openradar.discourse.group/t/clarification-on-choosing-master-radar-and-grid-origin-in-pydda-dual-doppler-retrievals/650 "2025-11-25T18:58:04Z")
Both radars have different locations. I am currently using the following code: link : Retrieving your first wind field — PyDDA 2.1.1 documentation grid\_ktlx = pyart.map.grid\_from\_radars(\[radar\_ktlx\], grid\_limits=grid\_li… --- ## [Different altitudes?](https://openradar.discourse.group/t/different-altitudes/641)
**Author:** [@imd](https://openradar.discourse.group/u/imd)\ **Replies:** 2\ **Last updated:** [August 27, 2025, 7:16pm UTC](https://openradar.discourse.group/t/different-altitudes/641 "2025-08-27T19:16:08Z")
How does PyDDA handle data from two radars with different altitudes? Specifically, I’m working with data from a C-band radar at 673 m MSL and an X-band radar at 272 m MSL? --- ## [Proper use of station data: pydda.constraints.get\_iem\_obs](https://openradar.discourse.group/t/proper-use-of-station-data-pydda-constraints-get-iem-obs/625)
**Author:** [@imd](https://openradar.discourse.group/u/imd)\ **Replies:** 0\ **Last updated:** [July 16, 2025, 8:41pm UTC](https://openradar.discourse.group/t/proper-use-of-station-data-pydda-constraints-get-iem-obs/625 "2025-07-16T20:41:11Z")
It would be helpful if someone could provide an example of using pydda.constraints.get\_iem\_obs(). Specifically, I’m noticing that I’m getting similar results with or without specifying points=st when retrieving wind data… --- ## [Can anyone explain the filter\_window and filter\_order parameters in get\_dd\_wind\_field?](https://openradar.discourse.group/t/can-anyone-explain-the-filter-window-and-filter-order-parameters-in-get-dd-wind-field/589)
**Author:** [@imd](https://openradar.discourse.group/u/imd)\ **Replies:** 1\ **Last updated:** [April 14, 2025, 11:07am UTC](https://openradar.discourse.group/t/can-anyone-explain-the-filter-window-and-filter-order-parameters-in-get-dd-wind-field/589 "2025-04-14T11:07:11Z")
I’m interested in understanding the filter\_window and filter\_order parameters in the get\_dd\_wind\_field function. Specifically, I’d like to know how they affect the output and why I don’t see much difference between filte… --- ## [Saving PyDDA Output Grids to NetCDF Files and Using Output Grids in another Script](https://openradar.discourse.group/t/saving-pydda-output-grids-to-netcdf-files-and-using-output-grids-in-another-script/592)
**Author:** [@BookWorm2022](https://openradar.discourse.group/u/BookWorm2022)\ **Replies:** 0\ **Last updated:** [April 18, 2025, 7:38pm UTC](https://openradar.discourse.group/t/saving-pydda-output-grids-to-netcdf-files-and-using-output-grids-in-another-script/592 "2025-04-18T19:38:44Z")
Hey, y’all! I’m currently working on a Dual-Doppler Analysis for my Master’s thesis, and I’m using PyDDA since previous students in my research group have used it. However, because I want to play around with plotting t… --- ## [Weird Vertical Velocities Post-PyDDA-Retrieval](https://openradar.discourse.group/t/weird-vertical-velocities-post-pydda-retrieval/131)
**Author:** [@adiste5](https://openradar.discourse.group/u/adiste5)\ **Replies:** 5\ **Last updated:** [December 1, 2024, 11:32am UTC](https://openradar.discourse.group/t/weird-vertical-velocities-post-pydda-retrieval/131 "2024-12-01T11:32:46Z")
Hi! I’ve run PyDDA over two PNW coastal radars, KLGX and KRTX. The initial horizontal wind field looks good (Fig. ADS1), but when I try to plot vertical velocity, I get very strange values, especially around the cone of… --- ## [How to calculate cm , co ,cx,xy and cz value?](https://openradar.discourse.group/t/how-to-calculate-cm-co-cx-xy-and-cz-value/530)
**Author:** [@imd](https://openradar.discourse.group/u/imd)\ **Replies:** 8\ **Last updated:** [November 27, 2024, 4:05pm UTC](https://openradar.discourse.group/t/how-to-calculate-cm-co-cx-xy-and-cz-value/530 "2024-11-27T16:05:39Z")
grids\_out, \_ = pydda.retrieval.get\_dd\_wind\_field(\[grid\_kict, grid\_ktlx\], Cm=256.0, Co=1e-2, Cx=1, Cy=1, Cz=1, Cmod=1e-5, model\_fields=\[“hrrr”\], refl\_field=‘DBZ’, wind\_tol=0.5, max\_iterations=50, filter\_window=15, fi… --- ## [PyDDA wind retrieval using single DWR](https://openradar.discourse.group/t/pydda-wind-retrieval-using-single-dwr/475)
**Author:** [@VTIITI](https://openradar.discourse.group/u/VTIITI)\ **Replies:** 3\ **Last updated:** [June 13, 2024, 11:27am UTC](https://openradar.discourse.group/t/pydda-wind-retrieval-using-single-dwr/475 "2024-06-13T11:27:26Z")
Is there any example notebook available to use pydda for single DWR? --- ## [PyDDA retrieve wind](https://openradar.discourse.group/t/pydda-retrieve-wind/462)
**Author:** [@woxiangxin](https://openradar.discourse.group/u/woxiangxin)\ **Replies:** 0\ **Last updated:** [April 23, 2024, 6:04am UTC](https://openradar.discourse.group/t/pydda-retrieve-wind/462 "2024-04-23T06:04:02Z")
Here is my retrieve result. I think there are some issues with this result, especially around the zero-velocity line. The wind direction should be orthogonal to the zero-velocity line, but in the figure, the wind is dire… --- ## [Pydda output grids to netcdf](https://openradar.discourse.group/t/pydda-output-grids-to-netcdf/448)
**Author:** [@shridharIITM](https://openradar.discourse.group/u/shridharIITM)\ **Replies:** 2\ **Last updated:** [April 8, 2024, 5:34pm UTC](https://openradar.discourse.group/t/pydda-output-grids-to-netcdf/448 "2024-04-08T17:34:12Z")
Hi all I am working with Pydda for dual Doppler analysis. I want to write pydda output grids (a list of size 2) to NetCDF file using pyart.io.write\_grid, so that it would be easy to plot after analysis but is not workin… --- ## [PyDDA installation issue](https://openradar.discourse.group/t/pydda-installation-issue/410)
**Author:** [@shridharIITM](https://openradar.discourse.group/u/shridharIITM)\ **Replies:** 1\ **Last updated:** [February 27, 2024, 4:02pm UTC](https://openradar.discourse.group/t/pydda-installation-issue/410 "2024-02-27T16:02:54Z")
Dear sir I am trying to install PyDDA but facing some problems as below. I am using the Anaconda3 environment with the win-64 platform. Python version is 3.11.8 and Pyart is 1.17.0. I installed PyDDA using ,conda inst… --- ## [PyDDA with more than 2 radars](https://openradar.discourse.group/t/pydda-with-more-than-2-radars/376)
**Author:** [@hvagasky](https://openradar.discourse.group/u/hvagasky)\ **Replies:** 2\ **Last updated:** [January 19, 2024, 10:13pm UTC](https://openradar.discourse.group/t/pydda-with-more-than-2-radars/376 "2024-01-19T22:13:57Z")
Hi, When PyDDA retrieves winds with more than 2 radars does it only conduct the retrieval over regions where all of the radars overlap? I have a case with data from 6 radars. I am finding that the region where winds are… --- ## [AttributeError: module 'osgeo.\_gdalconst' has no attribute 'GDT\_Int8'](https://openradar.discourse.group/t/attributeerror-module-osgeo-gdalconst-has-no-attribute-gdt-int8/333)
**Author:** [@JVB](https://openradar.discourse.group/u/JVB)\ **Replies:** 7\ **Last updated:** [October 27, 2023, 11:44am UTC](https://openradar.discourse.group/t/attributeerror-module-osgeo-gdalconst-has-no-attribute-gdt-int8/333 "2023-10-27T11:44:56Z")
Hello, I’m facing the error:" AttributeError: module ‘osgeo.\_gdalconst’ has no attribute ‘GDT\_Int8’" when importing gdal as: from osgeo import gdal This is a new environment, that I created following the steps: … --- ## [Pydda wind estimation](https://openradar.discourse.group/t/pydda-wind-estimation/315)
**Author:** [@shridharIITM](https://openradar.discourse.group/u/shridharIITM)\ **Replies:** 9\ **Last updated:** [September 22, 2023, 9:46pm UTC](https://openradar.discourse.group/t/pydda-wind-estimation/315 "2023-09-22T21:46:33Z")
I have tried to retrieve wind using Pydda and gridded the data at 1km along x, y and 0.5km along z axis… I have averaged the at each height level and tried to compared with GPS-sonde observation and VAD method… I have do… --- ## [Cross-section question and y-levels, w\_vel\_contour](https://openradar.discourse.group/t/cross-section-question-and-y-levels-w-vel-contour/318)
**Author:** [@CB2Bee](https://openradar.discourse.group/u/CB2Bee)\ **Replies:** 1\ **Last updated:** [September 22, 2023, 9:43pm UTC](https://openradar.discourse.group/t/cross-section-question-and-y-levels-w-vel-contour/318 "2023-09-22T21:43:39Z")
Hi, I am plotting radar data with HRRR to initialize the winds in a supercell thunderstorm. How does one determine the level of y in pydda.vis.plot\_xz\_xsection\_barbs to correctly slice the storm? I did some guessing wi… --- ## [PyDDA 1.4.0 released](https://openradar.discourse.group/t/pydda-1-4-0-released/297)
**Author:** [@rcjackson](https://openradar.discourse.group/u/rcjackson)\ **Replies:** 0\ **Last updated:** [August 31, 2023, 2:45pm UTC](https://openradar.discourse.group/t/pydda-1-4-0-released/297 "2023-08-31T14:45:17Z")
PyDDA 1.4.0 has been released today! In this version of PyDDA we have: \* Moved to ruff for linting and added pre-commit hooks to better ensure code quality in PRs. \* Expanded unit testing of Jax/TensorFlow cost functio… --- ## [Magnitudes in retrieved Vertical Velocities PyDDA](https://openradar.discourse.group/t/magnitudes-in-retrieved-vertical-velocities-pydda/280)
**Author:** [@hvagasky](https://openradar.discourse.group/u/hvagasky)\ **Replies:** 13\ **Last updated:** [August 23, 2023, 6:58pm UTC](https://openradar.discourse.group/t/magnitudes-in-retrieved-vertical-velocities-pydda/280 "2023-08-23T18:58:05Z")
Hi, I am retrieving winds from KVNX and KICT using PyDDA. The magnitude of the vertical velocity maximizes right near the axis between the radars and decreases with distance in what seems to be an unphysical manner. Do … --- ## [PyDDA 1.3.1 released today with several bugfixes](https://openradar.discourse.group/t/pydda-1-3-1-released-today-with-several-bugfixes/279)
**Author:** [@rcjackson](https://openradar.discourse.group/u/rcjackson)\ **Replies:** 0\ **Last updated:** [July 27, 2023, 9:36am UTC](https://openradar.discourse.group/t/pydda-1-3-1-released-today-with-several-bugfixes/279 "2023-07-27T09:36:17Z")
Today we have released PyDDA 1.3.1. This version has three major bugfixes: The weights from the final radar in the specified list were being set to zero by default. Now the coverage for the last radar is calculated cor… --- ## [Weighing constants for PyDDA](https://openradar.discourse.group/t/weighing-constants-for-pydda/205)
**Author:** [@hvagasky](https://openradar.discourse.group/u/hvagasky)\ **Replies:** 5\ **Last updated:** [July 13, 2023, 7:52am UTC](https://openradar.discourse.group/t/weighing-constants-for-pydda/205 "2023-07-13T07:52:24Z")
Hi. Is there additional documentation or guidance on how to determine the appropriate weights or what is an appropriate range for the weights to use in PyDDA besides Welcome to the PyDDA documentation! — PyDDA 1.2.0 docu… --- ## [Moving PyDDA questions to the openradar discourse](https://openradar.discourse.group/t/moving-pydda-questions-to-the-openradar-discourse/115)
**Author:** [@rcjackson](https://openradar.discourse.group/u/rcjackson)\ **Replies:** 1\ **Last updated:** [December 7, 2022, 4:07pm UTC](https://openradar.discourse.group/t/moving-pydda-questions-to-the-openradar-discourse/115 "2022-12-07T16:07:31Z")
I am going to be moving all general questions about PyDDA to this discourse group while requesting that questions about PyDDA. I appear to not have tag creation privleges. Would it be possible for someone to make a ‘pydd…