# Can't download CRTM\_COEF V1.0

**URL:** <https://forums.jcsda.org/t/cant-download-crtm-coef-v1-0/358>\
**Category:** CRTM\
**Created:** [July 28, 2022, 1:42am UTC](https://forums.jcsda.org/t/cant-download-crtm-coef-v1-0/358 "2022-07-28T01:42:30Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![zach](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.jcsda.org/zach/32/153_2.png) [@zach](https://forums.jcsda.org/u/zach)\
**Post date:** [July 28, 2022, 1:42am UTC](https://forums.jcsda.org/t/cant-download-crtm-coef-v1-0/358/1 "2022-07-28T01:42:30Z")

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Following the user guide, CRTM\_COEF V1.0 is the first release of the transmittance coefficient generation code for the Community Radiative Transfer Model (CRTM), v2.4.0 and older. And I would like to use FY4-GIIRS sensor coefficient in this file. But the github website [https://github.com/JCSDA-internal/CRTM\_coef](https://github.com/JCSDA-internal/CRTM_coef) is not available. I also run sh Get\_CRTM\_Binary\_Files.sh on Linux, but there is still no FY4-GIIRS sensor coefficient. How can I solve this problem? Very thanks.

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**Author:** ![StegmannJCSDA](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.jcsda.org/stegmannjcsda/32/53_2.png) [@StegmannJCSDA](https://forums.jcsda.org/u/StegmannJCSDA)\
**Post date:** [July 28, 2022, 3:21pm UTC](https://forums.jcsda.org/t/cant-download-crtm-coef-v1-0/358/2 "2022-07-28T15:21:11Z")

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Hello @zach. Welcome to the JCSDA forum.

Please note that CRTM\_coef v1.0 is a restricted expert release for the time being, due to the complexity of the code.

The further steps really depend on what your final goal for the FY4-GIIRS instrument coefficients is.  
Could you tell us more about that?

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**Author:** ![zach](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.jcsda.org/zach/32/153_2.png) [@zach](https://forums.jcsda.org/u/zach)\
**Post date:** [July 28, 2022, 3:47pm UTC](https://forums.jcsda.org/t/cant-download-crtm-coef-v1-0/358/3 "2022-07-28T15:47:05Z")

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Thanks for your reply! I just want to calculate the brightness temperature of FY4-GIIRS under cloudy condition, so I think i might need its coefficient in CRTM.

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**Author:** ![StegmannJCSDA](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.jcsda.org/stegmannjcsda/32/53_2.png) [@StegmannJCSDA](https://forums.jcsda.org/u/StegmannJCSDA)\
**Post date:** [July 29, 2022, 6:06pm UTC](https://forums.jcsda.org/t/cant-download-crtm-coef-v1-0/358/4 "2022-07-29T18:06:56Z")

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@zach do you have access to the spectral response function for the FY4-GIIRS instrument?

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**Author:** ![zach](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.jcsda.org/zach/32/153_2.png) [@zach](https://forums.jcsda.org/u/zach)\
**Post date:** [August 2, 2022, 7:31am UTC](https://forums.jcsda.org/t/cant-download-crtm-coef-v1-0/358/5 "2022-08-02T07:31:16Z")

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Thanks for your reply! Sadly, I don’t think I have access to the spectral response function for the FY4-GIIRS.