# RF using channels BHZ, BH1, and BH2

**URL:** https://discourse.obspy.org/t/rf-using-channels-bhz-bh1-and-bh2/1140
**Category:** Related: rf
**Created:** [November 25, 2020, 3:27pm UTC](https://discourse.obspy.org/t/rf-using-channels-bhz-bh1-and-bh2/1140 "2020-11-25T15:27:09Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![jritsema](https://discourse.obspy.org/letter_avatar_proxy/v4/letter/j/bbe5ce/32.png) [@jritsema](https://discourse.obspy.org/u/jritsema)
#### Post date: [November 25, 2020, 3:27pm UTC](https://discourse.obspy.org/t/rf-using-channels-bhz-bh1-and-bh2/1140/1 "2020-11-25T15:27:09Z")

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Is it possible to use stream.rf() when the horizontal components are called BH1 and BH2 and when CMPAZ is defined in the SAC headers?

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### Author: ![trichter](https://discourse.obspy.org/user_avatar/discourse.obspy.org/trichter/32/226_2.png) [@trichter](https://discourse.obspy.org/u/trichter)
#### Post date: [November 26, 2020, 8:07am UTC](https://discourse.obspy.org/t/rf-using-channels-bhz-bh1-and-bh2/1140/2 "2020-11-26T08:07:40Z")

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No, that is not possible in an automatic manner. You can use [`stream.rotate('->ZNE')`](https://docs.obspy.org/packages/autogen/obspy.core.stream.Stream.rotate.html) method to rotate to ZNE components. You will then need an inventory object (which can be created from stationxml file with obspy.read\_inventory).