From 3363ace052d9137480ab715a540e997e07dfa088 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Wed, 25 Jun 2025 08:07:02 +0200
Subject: [PATCH 01/23] Add polo-smm

Add the polo spectral model for BIPV facades
---
 pvlib/spectrum/mismatch.py | 99 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)

diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index 980f0d0165..0fbcd80234 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -710,3 +710,102 @@ def spectral_factor_jrc(airmass, clearsky_index, module_type=None,
         + coeff[2] * (airmass - 1.5)
     )
     return mismatch
+
+def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi, altitude,
+                              module_type=None, coefficients=None, albedo=0.2):
+    """
+    Estimation of spectral mismatch for BIPV application in vertical facades.
+    
+   
+
+    Parameters
+    ----------
+    precipitable_water : numeric
+        atmospheric precipitable water. [cm]
+
+    airmass_absolute : numeric
+        absolute (pressure-adjusted) airmass. [unitless]
+
+    aod500 : numeric
+        atmospheric aerosol optical depth at 500 nm. [unitless]
+    
+    aoi : numeric
+        angle of incidence. [degrees]
+    
+    altitude: numeric
+        altitude over sea level. [m]    
+        
+    module_type : str, optional
+        One of the following PV technology strings from [1]_:
+
+        * ``'cdte'`` - anonymous CdTe module.
+        * ``'monosi'`` - anonymous sc-si module.
+        * ``'cigs'`` - anonymous copper indium gallium selenide module.
+        * ``'asi'`` - anonymous amorphous silicon module.
+    albedo
+        Ground albedo (default value if 0.2). [unitless]    
+
+    coefficients : array-like, optional
+        user-defined coefficients, if not using one of the default coefficient
+        sets via the ``module_type`` parameter.
+
+    Returns
+    -------
+    modifier: numeric
+        spectral mismatch factor (unitless) which is multiplied
+        with broadband irradiance reaching a module's cells to estimate
+        effective irradiance, i.e., the irradiance that is converted to
+        electrical current.
+
+    References
+    ----------
+    [1]. Polo, J., Sanz-saiz, C., Development of spectral mismatch models
+    for BIPV applications in building façades Abbreviations : Renew. Energy 245, 122820, 2025.
+    https://doi.org/10.1016/j.renene.2025.122820
+    
+    """
+    if module_type is None and coefficients is None:
+        raise ValueError('Must provide either `module_type` or `coefficients`')
+    if module_type is not None and coefficients is not None:
+        raise ValueError('Only one of `module_type` and `coefficients` should '
+                         'be provided')
+    
+    am_aoi=pvlib.atmosphere.get_relative_airmass(aoi)
+    pressure=pvlib.atmosphere.alt2pres(altitude)
+    am90=pvlib.atmosphere.get_absolute_airmass(am_aoi,pressure)
+    Ram=am90/airmass_absolute
+    
+    _coefficients={}
+    _coefficients['cdte']=(
+        -0.0009,46.80,49.20,-0.87, 0.00041,0.053 )
+    _coefficients['monosi']=(
+        0.0027,10.34,9.48,0.307,0.00077,0.006 )
+    _coefficients['cigs']=(
+        0.0017,2.33,1.30,0.11,0.00098,-0.0177 )
+    _coefficients['asi']=(
+        0.0024,7.32,7.09,-0.72,-0.0013,0.089 )
+    
+    c={}
+    c['asi']=(0.0056,-0.020,1.014)
+    c['cigs']=(-0.0009,-0.0003,1)
+    c['cdte']=(0.0021,-0.01,1.01)
+    c['monosi']=(0,-0.003,1.0)
+    
+    
+    if module_type is not None:
+        coeff = _coefficients[module_type]
+        c_albedo=c[module_type]
+    else:
+        coeff = coefficients
+        c_albedo=(0.0,0.0,1.0) # 0.2 albedo assumed
+        albedo=0.2
+    
+    
+    smm=coeff[0]*Ram+coeff[1]/(coeff[2]+Ram**coeff[3])+coeff[4]/aod500+coeff[5]*np.sqrt(precipitable_water)
+    # Ground albedo correction
+      
+    g=c_albedo[0]*(albedo/0.2)**2+c_albedo[1]*(albedo/0.2)+c_albedo[2]
+    
+        
+    return g*smm
+    
\ No newline at end of file

From ceba758c14c346f7e1703e7cadf2aa06c331b25d Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesuspolo@users.noreply.github.com>
Date: Wed, 25 Jun 2025 10:39:48 +0200
Subject: [PATCH 02/23] Apply suggestions from code review

Co-authored-by: Adam R. Jensen <39184289+AdamRJensen@users.noreply.github.com>
---
 pvlib/spectrum/mismatch.py | 66 +++++++++++++++++---------------------
 1 file changed, 29 insertions(+), 37 deletions(-)

diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index 0fbcd80234..4b194db537 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -711,13 +711,12 @@ def spectral_factor_jrc(airmass, clearsky_index, module_type=None,
     )
     return mismatch
 
-def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi, altitude,
-                              module_type=None, coefficients=None, albedo=0.2):
+
+def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
+                         altitude, module_type=None, coefficients=None,
+                         albedo=0.2):
     """
     Estimation of spectral mismatch for BIPV application in vertical facades.
-    
-   
-
     Parameters
     ----------
     precipitable_water : numeric
@@ -725,16 +724,12 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi, alti
 
     airmass_absolute : numeric
         absolute (pressure-adjusted) airmass. [unitless]
-
     aod500 : numeric
         atmospheric aerosol optical depth at 500 nm. [unitless]
-    
     aoi : numeric
         angle of incidence. [degrees]
-    
     altitude: numeric
-        altitude over sea level. [m]    
-        
+        altitude over sea level. [m]
     module_type : str, optional
         One of the following PV technology strings from [1]_:
 
@@ -743,11 +738,11 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi, alti
         * ``'cigs'`` - anonymous copper indium gallium selenide module.
         * ``'asi'`` - anonymous amorphous silicon module.
     albedo
-        Ground albedo (default value if 0.2). [unitless]    
+        Ground albedo (default value if 0.2). [unitless]
 
     coefficients : array-like, optional
         user-defined coefficients, if not using one of the default coefficient
-        sets via the ``module_type`` parameter.
+        set via the ``module_type`` parameter.
 
     Returns
     -------
@@ -761,7 +756,7 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi, alti
     ----------
     [1]. Polo, J., Sanz-saiz, C., Development of spectral mismatch models
     for BIPV applications in building façades Abbreviations : Renew. Energy 245, 122820, 2025.
-    https://doi.org/10.1016/j.renene.2025.122820
+    :doi:`10.1016/j.renene.2025.122820`
     
     """
     if module_type is None and coefficients is None:
@@ -776,36 +771,33 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi, alti
     Ram=am90/airmass_absolute
     
     _coefficients={}
-    _coefficients['cdte']=(
-        -0.0009,46.80,49.20,-0.87, 0.00041,0.053 )
-    _coefficients['monosi']=(
-        0.0027,10.34,9.48,0.307,0.00077,0.006 )
-    _coefficients['cigs']=(
-        0.0017,2.33,1.30,0.11,0.00098,-0.0177 )
-    _coefficients['asi']=(
-        0.0024,7.32,7.09,-0.72,-0.0013,0.089 )
-    
-    c={}
-    c['asi']=(0.0056,-0.020,1.014)
-    c['cigs']=(-0.0009,-0.0003,1)
-    c['cdte']=(0.0021,-0.01,1.01)
-    c['monosi']=(0,-0.003,1.0)
+    _coefficients = {
+        'cdte': (-0.0009, 46.80, 49.20, -0.87, 0.00041, 0.053),
+        'monosi': (0.0027, 10.34, 9.48, 0.307, 0.00077, 0.006),
+        'cigs': (0.0017, 2.33, 1.30, 0.11, 0.00098, -0.0177),
+        'asi': (0.0024, 7.32, 7.09, -0.72, -0.0013, 0.089),
+    }
     
+    c = {
+        'asi': (0.0056, -0.020, 1.014),
+        'cigs': (-0.0009, -0.0003, 1),
+        'cdte': (0.0021, -0.01, 1.01),
+        'monosi': (0, -0.003, 1.0),
+    }
     
     if module_type is not None:
         coeff = _coefficients[module_type]
-        c_albedo=c[module_type]
+        c_albedo = c[module_type]
     else:
         coeff = coefficients
-        c_albedo=(0.0,0.0,1.0) # 0.2 albedo assumed
-        albedo=0.2
-    
+        c_albedo = (0.0, 0.0, 1.0)  # 0.2 albedo assumed
+        albedo = 0.2
     
-    smm=coeff[0]*Ram+coeff[1]/(coeff[2]+Ram**coeff[3])+coeff[4]/aod500+coeff[5]*np.sqrt(precipitable_water)
+    smm = coeff[0] * Ram + coeff[1] / (coeff[2] + Ram**coeff[3]) \
+        + coeff[4] / aod500 + coeff[5]*np.sqrt(precipitable_water)
+
     # Ground albedo correction
-      
-    g=c_albedo[0]*(albedo/0.2)**2+c_albedo[1]*(albedo/0.2)+c_albedo[2]
-    
-        
+    g = c_albedo[0] * (albedo/0.2)**2 \
+        + c_albedo[1] * (albedo/0.2) + c_albedo[2]
+
     return g*smm
-    
\ No newline at end of file

From 36c9b43dbf805ba82f26680cd81dbadfd0d75447 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Wed, 25 Jun 2025 11:53:33 +0200
Subject: [PATCH 03/23] Update mismatch.py

---
 pvlib/spectrum/mismatch.py | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index 4b194db537..f10dc5d8dc 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -755,8 +755,8 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
     References
     ----------
     [1]. Polo, J., Sanz-saiz, C., Development of spectral mismatch models
-    for BIPV applications in building façades Abbreviations : Renew. Energy 245, 122820, 2025.
-    :doi:`10.1016/j.renene.2025.122820`
+    for BIPV applications in building façades Abbreviations : Renew. Energy 245
+    ,122820, 2025.:doi:`10.1016/j.renene.2025.122820`
     
     """
     if module_type is None and coefficients is None:
@@ -765,12 +765,12 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
         raise ValueError('Only one of `module_type` and `coefficients` should '
                          'be provided')
     
-    am_aoi=pvlib.atmosphere.get_relative_airmass(aoi)
-    pressure=pvlib.atmosphere.alt2pres(altitude)
-    am90=pvlib.atmosphere.get_absolute_airmass(am_aoi,pressure)
-    Ram=am90/airmass_absolute
+    am_aoi = pvlib.atmosphere.get_relative_airmass(aoi)
+    pressure = pvlib.atmosphere.alt2pres(altitude)
+    am90 = pvlib.atmosphere.get_absolute_airmass(am_aoi,pressure)
+    Ram = am90/airmass_absolute
     
-    _coefficients={}
+    _coefficients = {}
     _coefficients = {
         'cdte': (-0.0009, 46.80, 49.20, -0.87, 0.00041, 0.053),
         'monosi': (0.0027, 10.34, 9.48, 0.307, 0.00077, 0.006),

From eaa90b4281c240991b260198b193af464c6f5309 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Wed, 25 Jun 2025 12:09:19 +0200
Subject: [PATCH 04/23] Update mismatch.py

---
 pvlib/spectrum/mismatch.py | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index f10dc5d8dc..375b9f340b 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -757,19 +757,16 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
     [1]. Polo, J., Sanz-saiz, C., Development of spectral mismatch models
     for BIPV applications in building façades Abbreviations : Renew. Energy 245
     ,122820, 2025.:doi:`10.1016/j.renene.2025.122820`
-    
     """
     if module_type is None and coefficients is None:
         raise ValueError('Must provide either `module_type` or `coefficients`')
     if module_type is not None and coefficients is not None:
         raise ValueError('Only one of `module_type` and `coefficients` should '
                          'be provided')
-    
     am_aoi = pvlib.atmosphere.get_relative_airmass(aoi)
     pressure = pvlib.atmosphere.alt2pres(altitude)
-    am90 = pvlib.atmosphere.get_absolute_airmass(am_aoi,pressure)
+    am90 = pvlib.atmosphere.get_absolute_airmass(am_aoi, pressure)
     Ram = am90/airmass_absolute
-    
     _coefficients = {}
     _coefficients = {
         'cdte': (-0.0009, 46.80, 49.20, -0.87, 0.00041, 0.053),
@@ -777,27 +774,22 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
         'cigs': (0.0017, 2.33, 1.30, 0.11, 0.00098, -0.0177),
         'asi': (0.0024, 7.32, 7.09, -0.72, -0.0013, 0.089),
     }
-    
     c = {
         'asi': (0.0056, -0.020, 1.014),
         'cigs': (-0.0009, -0.0003, 1),
         'cdte': (0.0021, -0.01, 1.01),
         'monosi': (0, -0.003, 1.0),
     }
-    
-    if module_type is not None:
+     if module_type is not None:
         coeff = _coefficients[module_type]
         c_albedo = c[module_type]
     else:
         coeff = coefficients
         c_albedo = (0.0, 0.0, 1.0)  # 0.2 albedo assumed
         albedo = 0.2
-    
     smm = coeff[0] * Ram + coeff[1] / (coeff[2] + Ram**coeff[3]) \
         + coeff[4] / aod500 + coeff[5]*np.sqrt(precipitable_water)
-
     # Ground albedo correction
     g = c_albedo[0] * (albedo/0.2)**2 \
         + c_albedo[1] * (albedo/0.2) + c_albedo[2]
-
     return g*smm

From 794ed9898ecef4ff735c6260c6d81608e701ed74 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Wed, 25 Jun 2025 12:17:39 +0200
Subject: [PATCH 05/23] Update mismatch.py

---
 pvlib/spectrum/mismatch.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index 375b9f340b..df1349d21a 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -780,7 +780,7 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
         'cdte': (0.0021, -0.01, 1.01),
         'monosi': (0, -0.003, 1.0),
     }
-     if module_type is not None:
+    if module_type is not None:
         coeff = _coefficients[module_type]
         c_albedo = c[module_type]
     else:

From 7926a3d821763b6a32d9d8fab7b6cbffa131df23 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Wed, 25 Jun 2025 12:51:55 +0200
Subject: [PATCH 06/23] Update mismatch.py

---
 pvlib/spectrum/mismatch.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index df1349d21a..da00e28fdc 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -754,9 +754,9 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
 
     References
     ----------
-    [1]. Polo, J., Sanz-saiz, C., Development of spectral mismatch models
-    for BIPV applications in building façades Abbreviations : Renew. Energy 245
-    ,122820, 2025.:doi:`10.1016/j.renene.2025.122820`
+    [1] J. Polo and C. Sanz-Saiz, 'Development of spectral mismatch models
+    for BIPV applications in building façades', Renewable Energy, vol. 245,
+    p. 122820, Jun. 2025,:doi:`10.1016/j.renene.2025.122820`
     """
     if module_type is None and coefficients is None:
         raise ValueError('Must provide either `module_type` or `coefficients`')

From 988557c061187d06d55cc32d5e15cd6b6f5ae093 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Fri, 11 Jul 2025 13:36:14 +0200
Subject: [PATCH 07/23] Update mismatch.py

---
 pvlib/spectrum/mismatch.py | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index da00e28fdc..2f87565079 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -716,33 +716,33 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
                          altitude, module_type=None, coefficients=None,
                          albedo=0.2):
     """
-    Estimation of spectral mismatch for BIPV application in vertical facades.
+    Estimate the spectral mismatch for BIPV application in vertical facades.
     Parameters
     ----------
     precipitable_water : numeric
         atmospheric precipitable water. [cm]
 
     airmass_absolute : numeric
-        absolute (pressure-adjusted) airmass. [unitless]
+        Absolute airmass. [unitless]
     aod500 : numeric
         atmospheric aerosol optical depth at 500 nm. [unitless]
     aoi : numeric
-        angle of incidence. [degrees]
+        Angle of incidence on the vertical surface. [degrees]
     altitude: numeric
         altitude over sea level. [m]
     module_type : str, optional
         One of the following PV technology strings from [1]_:
 
         * ``'cdte'`` - anonymous CdTe module.
-        * ``'monosi'`` - anonymous sc-si module.
+        * ``'monosi'`` - anonymous monocrystalline Si module.
         * ``'cigs'`` - anonymous copper indium gallium selenide module.
         * ``'asi'`` - anonymous amorphous silicon module.
     albedo
-        Ground albedo (default value if 0.2). [unitless]
+        Ground albedo (default value 0.2). [unitless]
 
     coefficients : array-like, optional
-        user-defined coefficients, if not using one of the default coefficient
-        set via the ``module_type`` parameter.
+        user-defined coefficients, if not using one of the coefficient
+        sets via the ``module_type`` parameter.
 
     Returns
     -------

From 45e768f884b4d7c7fe81c74c5f8896de92d274f5 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Mon, 28 Jul 2025 08:31:35 +0200
Subject: [PATCH 08/23] Update mismatch.py

---
 pvlib/spectrum/mismatch.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index 2f87565079..21b5301295 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -786,7 +786,6 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
     else:
         coeff = coefficients
         c_albedo = (0.0, 0.0, 1.0)  # 0.2 albedo assumed
-        albedo = 0.2
     smm = coeff[0] * Ram + coeff[1] / (coeff[2] + Ram**coeff[3]) \
         + coeff[4] / aod500 + coeff[5]*np.sqrt(precipitable_water)
     # Ground albedo correction

From 38e569425c8ed62a548eef6458b9d786ec27d498 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesuspolo@users.noreply.github.com>
Date: Mon, 28 Jul 2025 14:25:24 +0200
Subject: [PATCH 09/23] Update pvlib/spectrum/mismatch.py

Co-authored-by: Echedey Luis <80125792+echedey-ls@users.noreply.github.com>
---
 pvlib/spectrum/mismatch.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index 21b5301295..76022f7217 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -717,6 +717,7 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
                          albedo=0.2):
     """
     Estimate the spectral mismatch for BIPV application in vertical facades.
+
     Parameters
     ----------
     precipitable_water : numeric

From c24e013d6578b8a294971dda0d5a9273e4f15f73 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesuspolo@users.noreply.github.com>
Date: Mon, 28 Jul 2025 14:25:58 +0200
Subject: [PATCH 10/23] Update pvlib/spectrum/mismatch.py

Co-authored-by: Echedey Luis <80125792+echedey-ls@users.noreply.github.com>
---
 pvlib/spectrum/mismatch.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index 76022f7217..935f729474 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -722,7 +722,6 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
     ----------
     precipitable_water : numeric
         atmospheric precipitable water. [cm]
-
     airmass_absolute : numeric
         Absolute airmass. [unitless]
     aod500 : numeric

From 0a00f1bccfcb927cb10c6e5e3bb2a09083fca24a Mon Sep 17 00:00:00 2001
From: "Adam R. Jensen" <39184289+AdamRJensen@users.noreply.github.com>
Date: Sat, 25 Oct 2025 18:13:47 +0200
Subject: [PATCH 11/23] Changes from code review

---
 .../effects_on_pv_system_output/spectrum.rst  |  5 +++--
 pvlib/spectrum/mismatch.py                    | 21 ++++++++++---------
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/docs/sphinx/source/reference/effects_on_pv_system_output/spectrum.rst b/docs/sphinx/source/reference/effects_on_pv_system_output/spectrum.rst
index 982bc91742..b453a300ee 100644
--- a/docs/sphinx/source/reference/effects_on_pv_system_output/spectrum.rst
+++ b/docs/sphinx/source/reference/effects_on_pv_system_output/spectrum.rst
@@ -12,9 +12,10 @@ Spectrum
    spectrum.calc_spectral_mismatch_field
    spectrum.spectral_factor_caballero
    spectrum.spectral_factor_firstsolar
-   spectrum.spectral_factor_sapm
-   spectrum.spectral_factor_pvspec
    spectrum.spectral_factor_jrc
+   spectrum.spectral_factor_polo
+   spectrum.spectral_factor_pvspec
+   spectrum.spectral_factor_sapm
    spectrum.sr_to_qe
    spectrum.qe_to_sr
    spectrum.average_photon_energy
diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index 935f729474..e835a22e2b 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -723,22 +723,24 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
     precipitable_water : numeric
         atmospheric precipitable water. [cm]
     airmass_absolute : numeric
-        Absolute airmass. [unitless]
+        absolute (pressure-adjusted) airmass. See :term:`airmass_absolute`.
+        [unitless]
     aod500 : numeric
         atmospheric aerosol optical depth at 500 nm. [unitless]
     aoi : numeric
-        Angle of incidence on the vertical surface. [degrees]
+        Angle of incidence on the vertical surface.  See :term:`aoi`.
+        [degrees]
     altitude: numeric
         altitude over sea level. [m]
     module_type : str, optional
         One of the following PV technology strings from [1]_:
 
         * ``'cdte'`` - anonymous CdTe module.
-        * ``'monosi'`` - anonymous monocrystalline Si module.
+        * ``'monosi'`` - anonymous monocrystalline silicon module.
         * ``'cigs'`` - anonymous copper indium gallium selenide module.
         * ``'asi'`` - anonymous amorphous silicon module.
-    albedo
-        Ground albedo (default value 0.2). [unitless]
+    albedo : float, optional
+        Ground albedo (default value 0.2). See :term:`albedo`. [unitless]
 
     coefficients : array-like, optional
         user-defined coefficients, if not using one of the coefficient
@@ -754,9 +756,9 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
 
     References
     ----------
-    [1] J. Polo and C. Sanz-Saiz, 'Development of spectral mismatch models
-    for BIPV applications in building façades', Renewable Energy, vol. 245,
-    p. 122820, Jun. 2025,:doi:`10.1016/j.renene.2025.122820`
+    .. [1] J. Polo and C. Sanz-Saiz, 'Development of spectral mismatch models
+       for BIPV applications in building façades', Renewable Energy, vol. 245,
+       p. 122820, Jun. 2025, :doi:`10.1016/j.renene.2025.122820`
     """
     if module_type is None and coefficients is None:
         raise ValueError('Must provide either `module_type` or `coefficients`')
@@ -766,8 +768,7 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
     am_aoi = pvlib.atmosphere.get_relative_airmass(aoi)
     pressure = pvlib.atmosphere.alt2pres(altitude)
     am90 = pvlib.atmosphere.get_absolute_airmass(am_aoi, pressure)
-    Ram = am90/airmass_absolute
-    _coefficients = {}
+    Ram = am90 / airmass_absolute
     _coefficients = {
         'cdte': (-0.0009, 46.80, 49.20, -0.87, 0.00041, 0.053),
         'monosi': (0.0027, 10.34, 9.48, 0.307, 0.00077, 0.006),

From 2a9d0dbbc36b56e41d94c30cbaa441a3daa50242 Mon Sep 17 00:00:00 2001
From: "Adam R. Jensen" <39184289+AdamRJensen@users.noreply.github.com>
Date: Sat, 25 Oct 2025 18:19:46 +0200
Subject: [PATCH 12/23] Add function to spectrum/__init__.py

---
 pvlib/spectrum/__init__.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pvlib/spectrum/__init__.py b/pvlib/spectrum/__init__.py
index 59f9db9582..1e551c83fa 100644
--- a/pvlib/spectrum/__init__.py
+++ b/pvlib/spectrum/__init__.py
@@ -3,9 +3,10 @@
     calc_spectral_mismatch_field,
     spectral_factor_caballero,
     spectral_factor_firstsolar,
-    spectral_factor_sapm,
-    spectral_factor_pvspec,
     spectral_factor_jrc,
+    spectral_factor_polo,
+    spectral_factor_pvspec,
+    spectral_factor_sapm,
 )
 from pvlib.spectrum.irradiance import (  # noqa: F401
     get_reference_spectra,

From f296c7b1b782f65027d2c2449b8c8da649ac5538 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Mon, 27 Oct 2025 12:25:17 +0100
Subject: [PATCH 13/23] Update test_mismatch.py

---
 tests/spectrum/test_mismatch.py | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tests/spectrum/test_mismatch.py b/tests/spectrum/test_mismatch.py
index 69ed476f59..a22d9d595d 100644
--- a/tests/spectrum/test_mismatch.py
+++ b/tests/spectrum/test_mismatch.py
@@ -302,3 +302,21 @@ def test_spectral_factor_jrc_supplied_ambiguous():
     with pytest.raises(ValueError, match='No valid input provided'):
         spectrum.spectral_factor_jrc(1.0, 0.8, module_type=None,
                                      coefficients=None)
+@pytest.mark.parametrize("module_type,expected", [
+    ('cdte', np.array([0.991926, 0.999809, 1.01108, 0.993319, 0.956621, 0.970872])),
+    ('monosi', np.array([1.00174, 0.971769, 0.986224, 1.01661, 1.02026, 1.0106])),
+    ('cigs', np.array([1.00769,	0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
+    ('asi', np.array([0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
+])
+def test_spectral_factor_polo():
+    altitude=500
+
+    pws = np.array([0.96, 0.96, 1.85, 1.88, 0.66, 0.66])
+    aods = np.array([0.085, 0.085, 0.16, 0.19, 0.088, 0.088])
+    ams = np.array([1.34, 1.34, 2.2, 2.2, 2.6, 2.6])
+    aois = np.array([46.0, 76.0, 74.0, 28.0, 24.0, 55.0])
+    alb=np.array([0.15, 0.2, 0.3, 0.18, 0.32, 0.26])
+
+    out=spectral_factor_polo(pws,ams,aods,aois,altitude,module_type=module_type,albedo=alb)
+    assert np.allclose(expected, out, atol=1e-8)
+    
\ No newline at end of file

From ce862d8a120c27cef41aaa9aba3eba1850723f15 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Mon, 27 Oct 2025 12:37:54 +0100
Subject: [PATCH 14/23] Update test_mismatch.py

---
 tests/spectrum/test_mismatch.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/spectrum/test_mismatch.py b/tests/spectrum/test_mismatch.py
index a22d9d595d..7e85cc777b 100644
--- a/tests/spectrum/test_mismatch.py
+++ b/tests/spectrum/test_mismatch.py
@@ -308,7 +308,7 @@ def test_spectral_factor_jrc_supplied_ambiguous():
     ('cigs', np.array([1.00769,	0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
     ('asi', np.array([0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
 ])
-def test_spectral_factor_polo():
+def test_spectral_factor_polo(module_type,expected):
     altitude=500
 
     pws = np.array([0.96, 0.96, 1.85, 1.88, 0.66, 0.66])

From 11336ab34227fc624e190245e52214821513a044 Mon Sep 17 00:00:00 2001
From: "Adam R. Jensen" <39184289+AdamRJensen@users.noreply.github.com>
Date: Mon, 27 Oct 2025 12:46:07 +0100
Subject: [PATCH 15/23] Fix module import in tests

---
 tests/spectrum/test_mismatch.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/spectrum/test_mismatch.py b/tests/spectrum/test_mismatch.py
index 7e85cc777b..84e025569d 100644
--- a/tests/spectrum/test_mismatch.py
+++ b/tests/spectrum/test_mismatch.py
@@ -317,6 +317,7 @@ def test_spectral_factor_polo(module_type,expected):
     aois = np.array([46.0, 76.0, 74.0, 28.0, 24.0, 55.0])
     alb=np.array([0.15, 0.2, 0.3, 0.18, 0.32, 0.26])
 
-    out=spectral_factor_polo(pws,ams,aods,aois,altitude,module_type=module_type,albedo=alb)
+    out = spectrum.spectral_factor_polo(
+        pws,ams,aods,aois,altitude,module_type=module_type,albedo=alb)
     assert np.allclose(expected, out, atol=1e-8)
     
\ No newline at end of file

From e418218c756ed8f36948e5b28d32dea70d124f9c Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Mon, 27 Oct 2025 12:48:46 +0100
Subject: [PATCH 16/23] Update test_mismatch.py

---
 tests/spectrum/test_mismatch.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/spectrum/test_mismatch.py b/tests/spectrum/test_mismatch.py
index 7e85cc777b..84e025569d 100644
--- a/tests/spectrum/test_mismatch.py
+++ b/tests/spectrum/test_mismatch.py
@@ -317,6 +317,7 @@ def test_spectral_factor_polo(module_type,expected):
     aois = np.array([46.0, 76.0, 74.0, 28.0, 24.0, 55.0])
     alb=np.array([0.15, 0.2, 0.3, 0.18, 0.32, 0.26])
 
-    out=spectral_factor_polo(pws,ams,aods,aois,altitude,module_type=module_type,albedo=alb)
+    out = spectrum.spectral_factor_polo(
+        pws,ams,aods,aois,altitude,module_type=module_type,albedo=alb)
     assert np.allclose(expected, out, atol=1e-8)
     
\ No newline at end of file

From 450dd37c2b632cd5004a7750b4c3de402dcc9019 Mon Sep 17 00:00:00 2001
From: "Adam R. Jensen" <39184289+AdamRJensen@users.noreply.github.com>
Date: Mon, 27 Oct 2025 12:56:08 +0100
Subject: [PATCH 17/23] Fix linter

---
 tests/spectrum/test_mismatch.py | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/tests/spectrum/test_mismatch.py b/tests/spectrum/test_mismatch.py
index 84e025569d..acb1d3752a 100644
--- a/tests/spectrum/test_mismatch.py
+++ b/tests/spectrum/test_mismatch.py
@@ -302,22 +302,27 @@ def test_spectral_factor_jrc_supplied_ambiguous():
     with pytest.raises(ValueError, match='No valid input provided'):
         spectrum.spectral_factor_jrc(1.0, 0.8, module_type=None,
                                      coefficients=None)
+
+
 @pytest.mark.parametrize("module_type,expected", [
-    ('cdte', np.array([0.991926, 0.999809, 1.01108, 0.993319, 0.956621, 0.970872])),
-    ('monosi', np.array([1.00174, 0.971769, 0.986224, 1.01661, 1.02026, 1.0106])),
-    ('cigs', np.array([1.00769,	0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
-    ('asi', np.array([0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
+    ('cdte',
+     np.array([0.991926, 0.999809, 1.01108, 0.993319, 0.956621, 0.970872])),
+    ('monosi',
+     np.array([1.00174, 0.971769, 0.986224, 1.01661, 1.02026, 1.0106])),
+    ('cigs',
+     np.array([1.00769,	0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
+    ('asi',
+     np.array([0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
 ])
-def test_spectral_factor_polo(module_type,expected):
-    altitude=500
+def test_spectral_factor_polo(module_type, expected):
+    altitude = 500
 
     pws = np.array([0.96, 0.96, 1.85, 1.88, 0.66, 0.66])
     aods = np.array([0.085, 0.085, 0.16, 0.19, 0.088, 0.088])
     ams = np.array([1.34, 1.34, 2.2, 2.2, 2.6, 2.6])
     aois = np.array([46.0, 76.0, 74.0, 28.0, 24.0, 55.0])
-    alb=np.array([0.15, 0.2, 0.3, 0.18, 0.32, 0.26])
+    alb = np.array([0.15, 0.2, 0.3, 0.18, 0.32, 0.26])
 
     out = spectrum.spectral_factor_polo(
-        pws,ams,aods,aois,altitude,module_type=module_type,albedo=alb)
+        pws, ams, aods, aois, altitude, module_type=module_type, albedo=alb)
     assert np.allclose(expected, out, atol=1e-8)
-    
\ No newline at end of file

From 1eb3293197a61fcce506d6db08cd3657321f85c5 Mon Sep 17 00:00:00 2001
From: "Adam R. Jensen" <39184289+AdamRJensen@users.noreply.github.com>
Date: Mon, 27 Oct 2025 13:00:44 +0100
Subject: [PATCH 18/23] Remove tab character

---
 tests/spectrum/test_mismatch.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/spectrum/test_mismatch.py b/tests/spectrum/test_mismatch.py
index acb1d3752a..3c0d26c27c 100644
--- a/tests/spectrum/test_mismatch.py
+++ b/tests/spectrum/test_mismatch.py
@@ -310,7 +310,7 @@ def test_spectral_factor_jrc_supplied_ambiguous():
     ('monosi',
      np.array([1.00174, 0.971769, 0.986224, 1.01661, 1.02026, 1.0106])),
     ('cigs',
-     np.array([1.00769,	0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
+     np.array([1.00769, 0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
     ('asi',
      np.array([0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
 ])

From 4892e8d8b8aacf612e4f8d1cd3301b46e2b14000 Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Mon, 27 Oct 2025 13:47:01 +0100
Subject: [PATCH 19/23] Update test_mismatch.py

---
 tests/spectrum/test_mismatch.py | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/tests/spectrum/test_mismatch.py b/tests/spectrum/test_mismatch.py
index 84e025569d..9ae06dc86f 100644
--- a/tests/spectrum/test_mismatch.py
+++ b/tests/spectrum/test_mismatch.py
@@ -308,15 +308,13 @@ def test_spectral_factor_jrc_supplied_ambiguous():
     ('cigs', np.array([1.00769,	0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
     ('asi', np.array([0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
 ])
-def test_spectral_factor_polo(module_type,expected):
-    altitude=500
-
+def test_spectral_factor_polo(module_type, expected):
+    altitude = 500
     pws = np.array([0.96, 0.96, 1.85, 1.88, 0.66, 0.66])
     aods = np.array([0.085, 0.085, 0.16, 0.19, 0.088, 0.088])
     ams = np.array([1.34, 1.34, 2.2, 2.2, 2.6, 2.6])
     aois = np.array([46.0, 76.0, 74.0, 28.0, 24.0, 55.0])
-    alb=np.array([0.15, 0.2, 0.3, 0.18, 0.32, 0.26])
-
+    alb = np.array([0.15, 0.2, 0.3, 0.18, 0.32, 0.26])
     out = spectrum.spectral_factor_polo(
         pws,ams,aods,aois,altitude,module_type=module_type,albedo=alb)
     assert np.allclose(expected, out, atol=1e-8)

From 3e4dd567e9a65c9480854743f0cd935757cf7dfe Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Mon, 27 Oct 2025 13:59:54 +0100
Subject: [PATCH 20/23] Update test_mismatch.py

---
 tests/spectrum/test_mismatch.py | 20 ++++----------------
 1 file changed, 4 insertions(+), 16 deletions(-)

diff --git a/tests/spectrum/test_mismatch.py b/tests/spectrum/test_mismatch.py
index 705a7b4fc0..f665c45313 100644
--- a/tests/spectrum/test_mismatch.py
+++ b/tests/spectrum/test_mismatch.py
@@ -305,30 +305,18 @@ def test_spectral_factor_jrc_supplied_ambiguous():
 
 
 @pytest.mark.parametrize("module_type,expected", [
-    ('cdte',
-     np.array([0.991926, 0.999809, 1.01108, 0.993319, 0.956621, 0.970872])),
-    ('monosi',
-     np.array([1.00174, 0.971769, 0.986224, 1.01661, 1.02026, 1.0106])),
-    ('cigs',
-     np.array([1.00769, 0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
-    ('asi',
-     np.array([0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
+    ('cdte', np.array([0.991926, 0.999809, 1.01108, 0.993319, 0.956621, 0.970872])),
+    ('monosi', np.array([1.00174, 0.971769, 0.986224, 1.01661, 1.02026, 1.0106])),
+    ('cigs', np.array([1.00769, 0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
+    ('asi', np.array([0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
 ])
 def test_spectral_factor_polo(module_type, expected):
     altitude = 500
-<<<<<<< HEAD
-=======
-
->>>>>>> 1eb3293197a61fcce506d6db08cd3657321f85c5
     pws = np.array([0.96, 0.96, 1.85, 1.88, 0.66, 0.66])
     aods = np.array([0.085, 0.085, 0.16, 0.19, 0.088, 0.088])
     ams = np.array([1.34, 1.34, 2.2, 2.2, 2.6, 2.6])
     aois = np.array([46.0, 76.0, 74.0, 28.0, 24.0, 55.0])
     alb = np.array([0.15, 0.2, 0.3, 0.18, 0.32, 0.26])
-<<<<<<< HEAD
-=======
-
->>>>>>> 1eb3293197a61fcce506d6db08cd3657321f85c5
     out = spectrum.spectral_factor_polo(
         pws, ams, aods, aois, altitude, module_type=module_type, albedo=alb)
     assert np.allclose(expected, out, atol=1e-8)

From b9d21aca9a202a439378652005ebb8d88d1edc27 Mon Sep 17 00:00:00 2001
From: "Adam R. Jensen" <39184289+AdamRJensen@users.noreply.github.com>
Date: Tue, 28 Oct 2025 15:47:01 +0100
Subject: [PATCH 21/23] fix line legth linter error

---
 tests/spectrum/test_mismatch.py | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/tests/spectrum/test_mismatch.py b/tests/spectrum/test_mismatch.py
index f665c45313..1871b1066f 100644
--- a/tests/spectrum/test_mismatch.py
+++ b/tests/spectrum/test_mismatch.py
@@ -305,10 +305,14 @@ def test_spectral_factor_jrc_supplied_ambiguous():
 
 
 @pytest.mark.parametrize("module_type,expected", [
-    ('cdte', np.array([0.991926, 0.999809, 1.01108, 0.993319, 0.956621, 0.970872])),
-    ('monosi', np.array([1.00174, 0.971769, 0.986224, 1.01661, 1.02026, 1.0106])),
-    ('cigs', np.array([1.00769, 0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
-    ('asi', np.array([0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
+    ('cdte', np.array(
+        [0.991926, 0.999809, 1.01108, 0.993319, 0.956621, 0.970872])),
+    ('monosi', np.array(
+        [1.00174, 0.971769, 0.986224, 1.01661, 1.02026, 1.0106])),
+    ('cigs', np.array(
+        [1.00769, 0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
+    ('asi', np.array(
+        [0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
 ])
 def test_spectral_factor_polo(module_type, expected):
     altitude = 500

From 49c8c91a0631990ac42f969c15aafcaacf58989c Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Tue, 28 Oct 2025 16:30:20 +0100
Subject: [PATCH 22/23] Update test_mismatch.py

---
 tests/spectrum/test_mismatch.py | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/tests/spectrum/test_mismatch.py b/tests/spectrum/test_mismatch.py
index f665c45313..1871b1066f 100644
--- a/tests/spectrum/test_mismatch.py
+++ b/tests/spectrum/test_mismatch.py
@@ -305,10 +305,14 @@ def test_spectral_factor_jrc_supplied_ambiguous():
 
 
 @pytest.mark.parametrize("module_type,expected", [
-    ('cdte', np.array([0.991926, 0.999809, 1.01108, 0.993319, 0.956621, 0.970872])),
-    ('monosi', np.array([1.00174, 0.971769, 0.986224, 1.01661, 1.02026, 1.0106])),
-    ('cigs', np.array([1.00769, 0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
-    ('asi', np.array([0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
+    ('cdte', np.array(
+        [0.991926, 0.999809, 1.01108, 0.993319, 0.956621, 0.970872])),
+    ('monosi', np.array(
+        [1.00174, 0.971769, 0.986224, 1.01661, 1.02026, 1.0106])),
+    ('cigs', np.array(
+        [1.00769, 0.959666, 0.974438, 1.02861, 1.05203, 1.03117])),
+    ('asi', np.array(
+        [0.982133, 1.04674, 1.04859, 0.951109, 0.865328, 0.919515])),
 ])
 def test_spectral_factor_polo(module_type, expected):
     altitude = 500

From 31fe508376c00c86657064a1af584be2ac7a346a Mon Sep 17 00:00:00 2001
From: Jesus Polo <jesus.polo@ciemat.es>
Date: Wed, 29 Oct 2025 14:14:06 +0100
Subject: [PATCH 23/23] Update mismatch.py

---
 pvlib/spectrum/mismatch.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pvlib/spectrum/mismatch.py b/pvlib/spectrum/mismatch.py
index e835a22e2b..3e6e255ab8 100644
--- a/pvlib/spectrum/mismatch.py
+++ b/pvlib/spectrum/mismatch.py
@@ -769,6 +769,10 @@ def spectral_factor_polo(precipitable_water, airmass_absolute, aod500, aoi,
     pressure = pvlib.atmosphere.alt2pres(altitude)
     am90 = pvlib.atmosphere.get_absolute_airmass(am_aoi, pressure)
     Ram = am90 / airmass_absolute
+    f_aoi_rel= pvlib.atmosphere.get_relative_airmass(aoi, model='kastenyoung1989')
+    pressure = pvlib.atmosphere.alt2pres(altitude)
+    f_aoi = pvlib.atmosphere.get_absolute_airmass(f_aoi_rel, pressure)
+    Ram = f_aoi / airmass_absolute
     _coefficients = {
         'cdte': (-0.0009, 46.80, 49.20, -0.87, 0.00041, 0.053),
         'monosi': (0.0027, 10.34, 9.48, 0.307, 0.00077, 0.006),