# How to create a radar composite?

**URL:** <https://openradar.discourse.group/t/how-to-create-a-radar-composite/479>\
**Category:** General\
**Created:** [June 11, 2024, 1:24pm UTC](https://openradar.discourse.group/t/how-to-create-a-radar-composite/479 "2024-06-11T13:24:00Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![lou](https://avatars.discourse-cdn.com/v4/letter/l/ea666f/32.png) [@lou](https://openradar.discourse.group/u/lou)\
**Post date:** [June 11, 2024, 1:24pm UTC](https://openradar.discourse.group/t/how-to-create-a-radar-composite/479/1 "2024-06-11T13:24:00Z")

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Hi all,

as I can not find any open data for a nordic radar composite, I want to create one myself. But, I have never done this and might need some help from someone.

I have open data from each country (Finland, Sweden, Norway) as single radars **and** composites.

Is it possible to create a composite by merging the individual composites from each country, or must I merge the raw radar data from each country?

Best,  
Julian

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**Author:** ![jorahu](https://yyz2.discourse-cdn.com/free1/user_avatar/openradar.discourse.group/jorahu/32/19_2.png) [@jorahu](https://openradar.discourse.group/u/jorahu)\
**Post date:** [June 17, 2024, 8:07pm UTC](https://openradar.discourse.group/t/how-to-create-a-radar-composite/479/2 "2024-06-17T20:07:05Z")

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Hey

Did I understand correctly that you want to composite already composited (cartesian products) AND raw polar data? Or is it just 3 different cartesian products (three separate composites from each country)?

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**Author:** ![DavidDufton](https://avatars.discourse-cdn.com/v4/letter/d/cdc98d/32.png) [@DavidDufton](https://openradar.discourse.group/u/DavidDufton)\
**Post date:** [June 18, 2024, 1:18pm UTC](https://openradar.discourse.group/t/how-to-create-a-radar-composite/479/3 "2024-06-18T13:18:47Z")

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> [@lou](#):
>
> Is it possible to create a composite by merging the individual composites from each country, or must I merge the raw radar data from each country?

Both should be possible, though neither will necessarily be easy. To merge the individual composites you’ll need to check whether they’re all on a common grid. If not then the first step would be to interpolate/grid them to one, and then you’ll have to decide how to deal with the areas of overlapping coverage. In an ideal world you’d have quality information for all the composites, which you could then use to help with the compositing. If not, you could develop your own approach. This paper might be worth reading as a starting point: [https://rmets.onlinelibrary.wiley.com/doi/10.1002/met.1812](https://rmets.onlinelibrary.wiley.com/doi/10.1002/met.1812)

Processing all the polar data is obviously a bigger job but would allow you to have common processing and quality generation for all your data prior to compositing.