Introduce radiance_factor calibration level and standard name

[mraspaud]

This PR introduce the radiance_factor calibration level to refer to reflectance not yet normalised by the solar pathlength, along with the corresponding standard name.

• Closes Definition and accuracy of reflectance #52
• Tests added
• Fully documented
• abi_l1b.yaml
• abi_l1b_scmi.yaml
• abi_l2_nc.yaml
• acspo.yaml - no changes
• agri_fy4a_l1.yaml
• agri_fy4b_l1.yaml
• ahi_hrit.yaml
• ahi_hsd.yaml
• ahi_l1b_gridded_bin.yaml - reference says the data are reflectances, not touched
• ahi_l2_nc.yaml - no changes
• ami_l1b.yaml
• amsr2_l1b.yaml - no changes
• amsr2_l2.yaml - no changes
• amsr2_l2_gaasp.yaml - no changes
• amsub_l1c_aapp.yaml - no changes
• ascat_l2_soilmoisture_bufr.yaml - no changes
• atms_l1b_nc.yaml - no changes
• atms_sdr_hdf5.yaml - no changes
• avhrr_l0_hrpt.yaml
• avhrr_l1b_aapp.yaml
• avhrr_l1b_eps.yaml
• avhrr_l1b_gaclac.yaml
• avhrr_l1c_eum_gac_fdr_nc.yaml - the channels are named reflectance_channel_X
• aws1_mwr_l1b_nc.yaml - no changes
• aws1_mwr_l1c_nc.yaml - no changes
• caliop_l2_cloud.yaml - no changes
• camel_l3_nc.yaml - no changes
• clavrx.yaml - no changes
• cmsaf-claas2_l2_nc.yaml - no changes
• electrol_hrit.yaml - no changes
• epic_l1b_h5.yaml - no changes
• eps_sterna_mwr_l1b_nc.yaml
• etm_l1_tif.yaml - "real" reflectance: Top of the Atmosphere Reflectance, which is obtained using the scene center sun angle
• etm_l2_tif.yaml - surface reflectance
• fci_l1c_nc.yaml
• fci_l2_bufr.yaml - no changes
• fci_l2_grib.yaml - no changes
• fci_l2_nc.yaml - should this be left as-is even if the values are not the true reflectance?
• fy3a_mersi1_l1b.yaml
• fy3b_mersi1_l1b.yaml
• fy3c_mersi1_l1b.yaml
• generic_image.yaml - no changes
• geocat.yaml
• gerb_l2_hr_h5.yaml - no changes
• ghi_l1.yaml
• ghrsst_l2.yaml - no changes
• gld360_ualf2.yaml - no changes
• glm_l2.yaml - no changes
• gms5-vissr_l1b.yaml
• goci2_l2_nc.yaml - assume actual reflectances
• goes-imager_hrit.yaml
• goes-imager_nc.yaml
• gpm_imerg.yaml - no changes
• grib.yaml - no changes
• hsaf_grib.yaml - no changes
• hsaf_h5.yaml - no changes
• hy2_scat_l2b_h5.yaml - no changes
• iasi_l2.yaml - no changes
• iasi_l2_cdr_nc.yaml - no changes
• iasi_l2_so2_bufr.yaml - no changes
• iasi_ng_l2_nc.yaml - no changes
• ici_l1b_nc.yaml - no changes
• insat3d_img_l1b_h5.yaml
• jami_hrit.yaml
• li_l2_nc.yaml - no changes
• maia.yaml - no changes
• mcd12q1.yaml - no changes
• meris_nc_sen3.yaml - no changes, real reflectances
• mersi2_l1b.yaml
• mersi3_l1b.yaml
• mersi_ll_l1b.yaml
• mersi_rm_l1b.yaml
• mhs_l1c_aapp.yaml - no changes
• mimicTPW2_comp.yaml - no changes
• mirs.yaml - no changes
• modis_l1b.yaml
• modis_l2.yaml - no changes
• modis_l3.yaml - no changes
• msi_l1c_earthcare.yaml
• msi_safe.yaml - no changes, L1c data are "real" reflectances
• msi_safe_l2a.yaml - no changes, L2a data are "real" reflectances
• mss_l1_tif.yaml
• msu_gsa_l1b.yaml
• mtsat2-imager_hrit.yaml
• multiple_sensors_isccpng_l1g_nc.yaml
• mviri_l1b_fiduceo_nc.yaml
• mwi_l1b_nc.yaml - no changes
• mws_l1b_nc.yaml - no changes
• nucaps.yaml - no changes
• nwcsaf-geo.yaml - no changes
• nwcsaf-msg2013-hdf5.yaml - no changes
• nwcsaf-pps_nc.yaml - no changes
• oceancolorcci_l3_nc.yaml
• oci_l2_bgc.yaml - no changes
• olci_l1b.yaml
• olci_l2.yaml
• oli_tirs_l1_tif.yaml
• oli_tirs_l2_tif.yaml
• omps_edr.yaml
• osisaf_nc.yaml - no changes
• pace_oci_l1b_nc.yaml - no changes
• safe_sar_l2_ocn.yaml - no changes
• sar-c_safe.yaml - no changes
• satpy_cf_nc.yaml
• scatsat1_l2b.yaml - no changes
• seadas_l2.yaml - no changes
• seviri_l1b_hrit.yaml
• seviri_l1b_icare.yaml
• seviri_l1b_native.yaml
• seviri_l1b_nc.yaml
• seviri_l2_bufr.yaml - no changes
• seviri_l2_grib.yaml - no changes
• sgli_l1b.yaml
• slstr_l1b.yaml
• smos_l2_wind.yaml - no changes
• tm_l1_tif.yaml - no changes
• tm_l2_tif.yaml - no changes
• tropomi_l2.yaml - no changes
• vii_l1b_nc.yaml
• vii_l2_nc.yaml
• viirs_compact.yaml
• viirs_edr.yaml - no changes
• viirs_edr_active_fires.yaml - no changes
• viirs_edr_flood.yaml - no changes
• viirs_l1b.yaml
• viirs_l2.yaml - no changes
• viirs_sdr.yaml
• viirs_vgac_l1c_nc.yaml
• virr_l1b.yaml

[codecov]

Codecov Report

❌ Patch coverage is 99.18033% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 96.31%. Comparing base (b02f62d) to head (fadf3d8).
⚠️ Report is 82 commits behind head on main.

Files with missing lines	Patch %	Lines
satpy/readers/viirs_compact.py	50.00%	2 Missing ⚠️
satpy/readers/seviri_l1b_hrit.py	75.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##             main    #3292    +/-   ##
========================================
  Coverage   96.30%   96.31%            
========================================
  Files         463      463            
  Lines       58307    59101   +794     
========================================
+ Hits        56155    56924   +769     
- Misses       2152     2177    +25     

Flag	Coverage Δ
behaviourtests	3.59% <0.00%> (-0.05%)	⬇️
unittests	96.40% <99.18%> (+<0.01%)	⬆️

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[coveralls]

Pull Request Test Coverage Report for Build 19459512598

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 332 unchanged lines in 27 files lost coverage.
• Overall coverage increased (+0.01%) to 96.392%

---

Files with Coverage Reduction	New Missed Lines	%
readers/abi_l1b.py	1	98.9%
readers/hrit_jma.py	1	99.33%
readers/hrpt.py	1	98.67%
writers/init.py	1	76.92%
readers/mersi_l1b.py	2	98.57%
readers/slstr_l1b.py	2	97.5%
tests/compositor_tests/test_aux_data.py	2	97.33%
tests/reader_tests/test_abi_l1b.py	2	98.97%
writers/geotiff.py	2	91.78%
readers/ami_l1b.py	3	97.39%

Totals
Change from base Build 19264575612:	0.01%
Covered Lines:	56802
Relevant Lines:	58928

---

💛 - Coveralls

[mraspaud]

We would like to have a satpy config feature that allows for the user to enforce satpy 1.0 behaviour (crash when the wrong calibration level is used)

[gerritholl]

I have listed some definitions from various sources for radiance_factor and reflectance_factor at https://github.com/orgs/cf-convention/discussions/429#discussioncomment-15495012.