diff --git a/CHANGELOG b/CHANGELOG
index 35db4a1614f26eaa912a88f872c56ee9e743bbc5..00aa344bb87df45991d4f01673d799477cf0642d 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -466,3 +466,11 @@ Increased maximum number of records and introduced sort order to avoid that
 search request return a different result when repeated.
   py/cso_dataspace.py
 
+colhub branch
+~~~~~~~~~~~~~
+
+Support inquiry and use of ColHub mirror archive.
+  py/cso_colhub.py
+	py/cso_file.py
+	py/cso_s5p.py
+  py/cso.py
diff --git a/config/Copernicus/cso-s5p-no2.rc b/config/Copernicus/cso-s5p-no2.rc
index d9c3cbed8ceb7a54ec6b76858ec82fb6b7167735..5ae5685046af3119a3ba8774578776f0ad58494f 100644
--- a/config/Copernicus/cso-s5p-no2.rc
+++ b/config/Copernicus/cso-s5p-no2.rc
@@ -58,6 +58,47 @@ cso.s5p.no2.inquire-table-dataspace.download_url           :  https://zipper.dat
 cso.s5p.no2.inquire-table-dataspace.output.file            :  ${my.work}/Copernicus-inquire/Copernicus_S5p_NO2_dataspace__%Y-%m-%d.csv
 
 
+!-----------------------------------------------------------------------
+! inquire colhub mirror archive
+!-----------------------------------------------------------------------
+
+! csv file that will hold records per file with:
+! - timerange of pixels in file
+! - orbit number
+cso.s5p.no2.inquire-table-colhub-mirror.output.file         :  ${my.work}/Copernicus-inquire/Copernicus_S5p_NO2_colhub-listing__%Y-%m-%d.csv
+
+! renew table if file already exists?
+cso.s5p.no2.inquire-table-colhub-mirror.renew               :  True
+
+! base path; example file:
+!   <dir>/x0/x0/x1/S5P_OFFL_L2__NO2____20230701T002408_20230701T020537_29604_03_020500_20230702T161349.nc
+cso.s5p.no2.inquire-table-colhub-mirror.dir                 :  /lustre/storeB/project/ESAcolhub/production-backend-AOI/S5p/all
+! filename filter:
+cso.s5p.no2.inquire-table-colhub-mirror.pattern             :  S5P_*_L2__NO2_*.nc
+
+
+! ** create list of missing files
+
+! renew table if file already exists?
+cso.s5p.no2.inquire-table-colhub-missing.renew               :  True
+
+! csv file that will hold records per file with:
+! - timerange of pixels in file
+! - orbit number
+cso.s5p.no2.inquire-table-colhub-missing.output.file         :  ${my.work}/Copernicus-inquire/Copernicus_S5p_NO2_colhub-missing__%Y-%m-%d.csv
+
+! listing from DataSpace with all potentially available files:
+cso.s5p.no2.inquire-table-colhub-missing.all.file            :  ${cso.s5p.no2.inquire-table-dataspace.output.file}
+!cso.s5p.no2.inquire-table-colhub-missing.all.filedate        :  2025-01-23
+
+! listing from current archive:
+cso.s5p.no2.inquire-table-colhub-missing.curr.file           :  ${cso.s5p.no2.inquire-table-colhub-mirror.output.file}
+!cso.s5p.no2.inquire-table-colhub-missing.curr.filedate       :  2025-01-24
+
+! selection of orbits, see "convert" below:
+cso.s5p.no2.inquire-table-colhub-missing.selection           :  ${cso.s5p.no2.convert.selection}
+
+
 !!-----------------------------------------------------------------------
 !! inquire PAL portal
 !!-----------------------------------------------------------------------
diff --git a/config/Copernicus/cso-user-settings.rc b/config/Copernicus/cso-user-settings.rc
index b07f313fa919320b5b8474c1c36481d3edc5fb1d..b7252fe00ab5fd031c968d0c908f42245140d24e 100644
--- a/config/Copernicus/cso-user-settings.rc
+++ b/config/Copernicus/cso-user-settings.rc
@@ -34,6 +34,7 @@ my.cso.convention     :   CF-1.7
 ! region name:
 !my.region                       :  globe
 my.region                       :  CAMS
+!my.region                       :  xEMEP
 
 ! switch:
 !....................................
@@ -62,6 +63,19 @@ my.region.north                 :   76.0
 ! size of map figures for this region, default size is (8,6)
 my.region.figsize               :   (8,6)
 
+!....................................
+#elif "${my.region}" == "xEMEP"
+!....................................
+
+! outer bound of all known domains:
+my.region.west                  :  -50.0
+my.region.east                  :   90.0
+my.region.south                 :   25.0
+my.region.north                 :   85.0
+
+! size of map figures for this region, default size is (8,6)
+my.region.figsize               :   (8,5)
+
 !....................................
 #else
 #error unsupported my.region "${my.region}"
@@ -77,7 +91,7 @@ my.region.figsize               :   (8,6)
 
 ! full range, used for inquiry jobs:
 my.full-timerange.start         :  2018-01-01 00:00
-my.full-timerange.end           :  2023-12-31 23:59
+my.full-timerange.end           :  2024-12-31 23:59
 
 ! processing for selected period:
 my.timerange.start              :  2018-06-01 00:00
diff --git a/config/Copernicus/cso.rc b/config/Copernicus/cso.rc
index b773216ff69c63df3c91314158c2c8b688ce97a3..bc97fd187f8caabd0f70fdfca16710728c1d3c5e 100644
--- a/config/Copernicus/cso.rc
+++ b/config/Copernicus/cso.rc
@@ -82,6 +82,7 @@ cso.s5p.TRACER.inquire.class                      :  utopya.UtopyaJobStep
 ! two or more tasks:
 #if "TRACER" in ["no2","so2","hcho","co","o3-pr","o3-col"]
 cso.s5p.TRACER.inquire.tasks                      :  table-dataspace plot
+!cso.s5p.TRACER.inquire.tasks                      :  table-colhub-mirror table-colhub-missing
 #elif "TRACER" in ["so2-cobra"]
 cso.s5p.TRACER.inquire.tasks                      :  table-pal plot
 #elif "TRACER" in ["chocho"]
@@ -93,6 +94,14 @@ cso.s5p.TRACER.inquire.tasks                      :  table-glyretro table-pal pl
 cso.s5p.TRACER.inquire.table-dataspace.class      :  cso.CSO_DataSpace_Inquire
 cso.s5p.TRACER.inquire.table-dataspace.args       :  '${my.work}/rc/cso-s5p-TRACER.rc', \
                                                      rcbase='cso.s5p.TRACER.inquire-table-dataspace'
+!~ inquire file archive:
+cso.s5p.TRACER.inquire.table-colhub-mirror.class  :  cso.CSO_ColHubMirror_Inquire
+cso.s5p.TRACER.inquire.table-colhub-mirror.args   :  '${my.work}/rc/cso-s5p-TRACER.rc', \
+                                                     rcbase='cso.s5p.TRACER.inquire-table-colhub-mirror'
+!~ create table with files that are missing:
+cso.s5p.TRACER.inquire.table-colhub-missing.class :  cso.CSO_ColHubMirror_Missing
+cso.s5p.TRACER.inquire.table-colhub-missing.args  :  '${my.work}/rc/cso-s5p-TRACER.rc', \
+                                                     rcbase='cso.s5p.TRACER.inquire-table-colhub-missing'
 !~ inquire files available on PAL:
 cso.s5p.TRACER.inquire.table-pal.class            :  cso.CSO_PAL_Inquire
 cso.s5p.TRACER.inquire.table-pal.args             :  '${my.work}/rc/cso-s5p-TRACER.rc', \
diff --git a/doc/source/history.rst b/doc/source/history.rst
index 5b2a9e2d06f79231bc5cdabbf9686e270121c6be..69cc8c6b59be911da82852f08894d3a3a269b6cf 100644
--- a/doc/source/history.rst
+++ b/doc/source/history.rst
@@ -109,6 +109,9 @@ A summary of the versions and changes.
   
 * | *v2.9*
   | Initial support for S5P O3-profile product.
+  
+* | *colhub branch*
+  | Support inquiry of ColHub mirror archive.
 
 
 To be included
diff --git a/doc/source/index.rst b/doc/source/index.rst
index 579b0a4b5cd3f96990c5f1e6e99c3b7224d83f48..16d2c87e52a7a35a04b8d4b977bc83d19dc7be3e 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -42,6 +42,7 @@ Contents
    gridding
    superobs
    colocate
+   portals
    pymods
    history
    documentation
diff --git a/doc/source/portals.rst b/doc/source/portals.rst
new file mode 100644
index 0000000000000000000000000000000000000000..6e72cbf166fb7f1b24ac50b475e969f2eebd909a
--- /dev/null
+++ b/doc/source/portals.rst
@@ -0,0 +1,20 @@
+
+.. Label between '.. _' and ':' ; use :ref:`text <label>` for reference
+.. _modules-and-classes:
+
+************
+Data portals
+************
+
+Overview of data portals from where satellite observations are downloaded.
+
+* The main portal for Sentinel data is the `Copernicus DataSpace <https://dataspace.copernicus.eu/>`_.
+  See the :ref:`cso-dataspace` module for a detailed description.
+
+* The `Product Algorithm Laboratory <https://www.s5p-pal.com/>`_, or more specific, the
+  `S5P-PAL Data Portal <https://data-portal.s5p-pal.com/>`_ provides pre-operational Sentinel-5P data.
+  See the :ref:`cso-pal` module for a detailed description.
+
+* The Norwegion `ColHub <https://colhub.met.no>`_ archive is a (partial) mirror of the 
+  `Copernicus DataSpace <https://dataspace.copernicus.eu/>`_, with all orbits covering Norway and surrounding areas.
+  See the :ref:`cso-colhub` module for a detailed description.
diff --git a/doc/source/pymod-cso_colhub.rst b/doc/source/pymod-cso_colhub.rst
new file mode 100644
index 0000000000000000000000000000000000000000..ab95fb93f08e1a9a6efd8590d393b52adb979171
--- /dev/null
+++ b/doc/source/pymod-cso_colhub.rst
@@ -0,0 +1,5 @@
+.. Documentation for module.
+
+.. Import documentation from ".py" file:
+.. automodule:: cso_colhub
+
diff --git a/doc/source/pymods.rst b/doc/source/pymods.rst
index daeb06504d66ae35eec8acae999c720fcfa7e26e..65b9010a6059b333ace6884bf370cfd7f2a6d588 100644
--- a/doc/source/pymods.rst
+++ b/doc/source/pymods.rst
@@ -11,7 +11,7 @@ Overview of the Python module(s) and classes.
 CSO modules
 ===========
 
-The ``cso`` module provides the classes that do the work in the CSO pre-processor.
+The ``cso`` module provides the classes that do the work in the CSO pre- and post- processing.
 
 .. The following are names of '.rst' files in the 'doc/sources' directory ;
    this ensures that each sub-module is given a seperate page in the documentation.
@@ -29,6 +29,7 @@ Classes used for specific tasks are implemented in the ``cso_*`` modules.
    pymod-cso_inquire
    pymod-cso_dataspace
    pymod-cso_pal
+   pymod-cso_colhub
    pymod-cso_s5p
    pymod-cso_file
    pymod-cso_gridded
diff --git a/doc/source/s5p-no2.rst b/doc/source/s5p-no2.rst
index 6a04512643890467c58e0941b9e32e7bc802623c..e8da3dcd11219579a07ebbb1da7b728736addbaf 100644
--- a/doc/source/s5p-no2.rst
+++ b/doc/source/s5p-no2.rst
@@ -218,7 +218,7 @@ S5p/NO2 observations from KNMI have been available from at least these sources:
 
   *This is the operational version.*
 
-* `Product Algorithm Laboratory <https://www.s5p-pal.com/>`_, or more specif, the
+* `Product Algorithm Laboratory <https://www.s5p-pal.com/>`_, or more specific, the
   `S5P-PAL Data Portal <https://data-portal.s5p-pal.com/>`_;
   see the :ref:`cso-pal` module for a detailed description.
   
diff --git a/py/cso.py b/py/cso.py
index a6350ea592aec5127c316d2f4217fbb3200f02da..b7f572b3f1a9a3f03c1ad3dc0d4b0656053d9cd3 100644
--- a/py/cso.py
+++ b/py/cso.py
@@ -109,6 +109,7 @@ and are defined according to the following hierchy:
 from cso_file import *
 from cso_inquire import *
 from cso_dataspace import *
+from cso_colhub import *
 from cso_pal import *
 from cso_s5p import *
 from cso_gridded import *
diff --git a/py/cso_colhub.py b/py/cso_colhub.py
new file mode 100644
index 0000000000000000000000000000000000000000..9cd1fd15e2e4499f7cd9763bdcfe9c50d72be4df
--- /dev/null
+++ b/py/cso_colhub.py
@@ -0,0 +1,471 @@
+#
+# Changes
+#
+# 2022-09, Arjo Segers
+#   Updated documentation.
+#
+# 2023-06, Arjo Segers
+#   Use "pandas.concat()" instead of "df.append()" to avoid warnings.
+#
+# 2023-08, Arjo Segers
+#   Updated logging messages.
+#
+# 2023-08, Arjo Segers
+#   Reformatted using 'black'.
+#
+# 2035-01, Arjo Segers
+#   Extracted parts from former "cso_scihub.py" module to support "colhub",
+#   the Norwegian mirror site.
+#
+
+########################################################################
+###
+### help
+###
+########################################################################
+
+"""
+.. _cso-colhub:
+
+*********************
+``cso_colhub`` module
+*********************
+
+The :py:mod:`cso_colhub` module provides classes for accessing  data from the 
+Norwegian `ColHub <https://colhub.met.no>`_ archive.
+This is a (partial) mirror of the `Copernicus Open Access Hub <https://colhub.copernicus.eu/>`_ 
+with all orbits covering Norway and surrounding areas.
+
+The data can be accessed using a web-interface, 
+but for Met Norway users also directly from the storage.
+This module provides the :py:class:`.CSO_ColHubMirror_Inquire` to inquire the storage 
+to see what is already available.
+In addition, the :py:class:`.CSO_ColHubMirror_Missing` is available to create a table 
+that lists files that are in the DataSpace but not yet in the mirror;
+these could be used to make additional downloads.
+
+
+Class hierchy
+=============
+
+The classes and are defined according to the following hierchy:
+
+* :py:class:`.UtopyaRc`
+
+  * :py:class:`.CSO_ColHubMirror_Inquire`
+  * :py:class:`.CSO_ColHubMirror_Missing`
+
+
+
+Classes
+=======
+
+
+"""
+
+
+########################################################################
+###
+### modules
+###
+########################################################################
+
+# modules:
+import logging
+
+# tools:
+import utopya
+
+
+########################################################################
+###
+### create listing file for file archive
+###
+########################################################################
+
+
+class CSO_ColHubMirror_Inquire(utopya.UtopyaRc):
+
+    """
+    Create *listing* file for files available in file archive.
+    
+    The format is similar to the output of *inquiry* classes,
+    with per line a filename, the time range of pixels in the file, 
+    and other information extracted from the filenames::
+
+        filename                                                                              ;processing;start_time         ;end_time           ;orbit;collection;processor_version;href
+        S5P_RPRO_L2__CH4____20180430T001851_20180430T020219_02818_01_010301_20190513T141133.nc;RPRO      ;2018-04-30T00:18:51;2018-04-30T02:02:19;02818;01        ;010301           ;/archive/mirror/S5P_RPRO_L2__CH4____20180430T001851_20180430T020219_02818_01_010301_20190513T141133.nc
+        S5P_RPRO_L2__CH4____20180430T020021_20180430T034349_02819_01_010301_20190513T135953.nc;RPRO      ;2018-04-30T02:00:21;2018-04-30T03:43:49;02819;01        ;010301           ;/archive/mirror/S5P_RPRO_L2__CH4____20180430T020021_20180430T034349_02819_01_010301_20190513T135953.nc
+        :
+
+    This file could be used to scan for available versions and how they were produced.
+    
+    In the settings, define the base directory of the archive::
+    
+        <rcbase>.dir           :  /archive/mirror
+        
+    This directory is recursively scanned using the :py:class:`os.walk` class on files with a specified form::
+    
+        ! search S5P CH4 files:
+        <rcbase>.pattern       :  S5P_*_L2_CH4___*.nc
+
+    Specifiy the output file::    
+
+        ! csv file that will hold records per file with:
+        ! - timerange of pixels in file
+        ! - orbit number
+        ! time templates are replaced with todays date
+        <rcbase>.file        :  /Scratch/Copernicus/S5p/listing-CH4__%Y-%m-%d.csv
+        
+    An existing listing file is not replaced,
+    unless the following flag is set::
+
+        ! renew table?
+        <rcbase>.renew           :  True
+        
+    """
+
+    def __init__(self, rcfile, rcbase="", env={}, indent=""):
+
+        """
+        Scan file archive.
+        """
+
+        # modules:
+        import os
+        import datetime
+        #import glob
+        import collections
+        import fnmatch
+
+        # tools:
+        import cso_file
+
+        # info ...
+        logging.info( f"{indent}")
+        logging.info( f"{indent}** create listing file")
+        logging.info( f"{indent}")
+
+        # init base object:
+        utopya.UtopyaRc.__init__(self, rcfile=rcfile, rcbase=rcbase, env=env)
+
+        # renew output?
+        renew = self.GetSetting("renew", totype="bool")
+
+        # table file to be written:
+        lst_file = self.GetSetting("output.file")
+        # evaluate current time:
+        lst_file = datetime.datetime.now().strftime(lst_file)
+
+        # create?
+        if (not os.path.isfile(lst_file)) or renew:
+            # info ..
+            logging.info( f"{indent}create %s ..." % lst_file)
+
+            # initiallize for (re)creation:
+            listing = cso_file.CSO_Listing()
+
+            # archive directory:
+            archive_dir = self.GetSetting("dir")
+            # check ..
+            if not os.path.isdir(archive_dir):
+                logging.error(f"archive directory not found: {archive_dir}")
+                raise Exception
+            #endif
+            # pattern for data files:
+            fpattern = self.GetSetting("pattern")
+            
+            # recursively search for files:
+            for root, dirs, files in os.walk(archive_dir):
+
+                # loop over files:
+                for fname in files :
+                    # data file?
+                    if fnmatch.fnmatch( fname, fpattern ) :
+
+                        # already in table?
+                        if fname in listing:
+                            # info ...
+                            logging.info( f"{indent}  keep entry %s ..." % fname)
+                        else:
+                            # info ...
+                            logging.info( f"{indent}  add entry %s ..." % fname)
+                            # Example filename:
+                            #   S5P_RPRO_L2__CH4____20180430T001851_20180430T020219_02818_01_010301_20190513T141133.nc
+                            #
+                            # Some products have incorrect product id (should be 10 characters):
+                            #   S5P_OFFL_L2__CHOCHO___20200101T005246_20200101T023416_11487_01_010000_20210128.nc
+                            # The extracted product id is then truncated to 10 characters.
+                            #
+                            # basename:
+                            bname, ext = os.path.splitext(fname)
+                            # extract:
+                            try:
+                                # split in 3 parts:
+                                mission, processing, rest = bname.split("_", 2)
+                                # extract product id, should be 10 chars:
+                                product_id = rest[0:10]
+                                # adhoc fix: some files have too long product id:
+                                if rest.startswith("L2__CHOCHO__"):
+                                    rest = res[13:]
+                                else :
+                                    rest = rest[11:]
+                                #endif
+                                # remaining parts:
+                                (
+                                    start_time,
+                                    end_time,
+                                    orbit,
+                                    collection,
+                                    processor_version,
+                                    prod_time,
+                                ) = rest.split("_")
+                            except:
+                                logging.error(f"could not extract filename parts; expected format:")
+                                logging.error(f"  S5P_RPRO_L2__CH4____20180430T001851_"
+                                              +"20180430T020219_02818_01_010301_20190513T141133" )
+                                logging.error(f"found:")
+                                logging.error(f"  {bname}")
+                                raise
+                            # endif
+                            # headers in "inquire" tables:
+                            #    orbit;start_time;end_time;processing;collection;processor_version;filename;href
+                            # fill data record:
+                            data = collections.OrderedDict()
+                            tfmt = "%Y%m%dT%H%M%S"
+                            data["orbit"] = orbit
+                            data["start_time"] = datetime.datetime.strptime(start_time, tfmt)
+                            data["end_time"] = datetime.datetime.strptime(end_time, tfmt)
+                            data["processing"] = processing
+                            data["collection"] = collection
+                            data["processor_version"] = processor_version
+                            data["href"] = os.path.join(root,fname)
+                            # update record:
+                            listing.UpdateRecord( fname, data, indent= f"{indent}    ")
+                        # endif  # new record?
+
+                    #endif # name of data file
+                    
+                #endfor # files
+
+                ## testing ...
+                #if len(listing) >= 100 :
+                #    logging.warning( f"BREAK after {len(listing)} files ..." )
+                #    break
+                # endif
+
+            #endfor # walk
+
+            # sort:
+            listing.Sort(by="orbit")
+            # save:
+            listing.Save(lst_file,indent= f"{indent}  ")
+
+        else:
+            # info ..
+            logging.info( f"{indent}keep %s ..." % lst_file)
+        # endif
+
+        # info ...
+        logging.info( f"{indent}")
+        logging.info( f"{indent}** end archive listing")
+        logging.info( f"{indent}")
+
+    # enddef __init__
+
+
+# endclass CSO_ColHubMirror_Inquire
+
+
+
+
+########################################################################
+###
+### create listing files missing in archive
+###
+########################################################################
+
+
+class CSO_ColHubMirror_Missing(utopya.UtopyaRc):
+
+    """
+    Create *listing* file for files that are in one inquiry table but not in another one.
+    This could be used to complete a mirror archive.
+    
+    The format is similar to the output of *inquiry* classes,
+    with per line a filename, the time range of pixels in the file, and other information extracted from the filenames::
+
+        filename                                                                              ;start_time         ;end_time           ;orbit;processing;collection;processor_version;href
+        S5P_RPRO_L2__NO2____20180504T073130_20180504T091300_02879_03_020400_20221208T160012.nc;2018-05-04 07:31:30;2018-05-04 09:13:00;02879 ;RPRO     ;03        ;020400           ;https://zipper.dataspace.copernicus.eu/odata/v1/Products(ae43b35c-0569-4e1f-b8cb-0afc49790716)/$value
+        :
+
+    In the settings, define the listing file with all available data, for example the result of an inquiry step;
+    eventually add a timestamp to replace templates in the filename::
+    
+        <rcbase>.all.file           :  /work/inquire/Copernicus_S5p_NO2_dataspace__%Y-%m-%d.csv
+        !<rcbase>.all.filedate       :  2025-01-24
+        
+    Similar specify the name of the file that is listing the current mirror, 
+    probably the output of the :py:class:`CSO_ColHubMirror_Inquire` class::
+
+        <rcbase>.curr.file           :  /work/inquire/Copernicus_S5p_NO2_colhub-mirror__%Y-%m-%d.csv
+        !<rcbase>.curr.filedate       :  2025-01-24
+        
+    Specify a selection filter; this defines which of the orbit files are actually needed::
+   
+        ! Provide ';' seperated list of to decide if a particular orbit file should be processed.
+        ! If more than one file is available for a particular orbit (from "OFFL" and "RPRO" processing),
+        ! the file with the first match will be used.
+        ! The expressions should include templates '%{header}' for the column values.
+        !
+        <rcbase>.selection                     :  (%{collection} == '03') and (%{processing} == 'RPRO') ; \\
+                                                  (%{collection} == '03') and (%{processing} == 'OFFL')
+
+    Specifiy the output file::    
+
+        ! csv file that will hold records per file with:
+        ! - timerange of pixels in file
+        ! - orbit number
+        ! time templates are replaced with todays date
+        <rcbase>.file        :  /work/inquire/Copernicus_S5p_NO2_colhub-mirror-missing__%Y-%m-%d.csv
+        
+    An existing listing file is not replaced,
+    unless the following flag is set::
+
+        ! renew table?
+        <rcbase>.renew           :  True
+
+    """
+
+    def __init__(self, rcfile, rcbase="", env={}, indent=""):
+
+        """
+        Convert data.
+        """
+
+        # modules:
+        import os
+        import datetime
+        #import glob
+        import collections
+        import fnmatch
+
+        # tools:
+        import cso_file
+
+        # info ...
+        logging.info( f"{indent}")
+        logging.info( f"{indent}** create list of missing files")
+        logging.info( f"{indent}")
+
+        # init base object:
+        utopya.UtopyaRc.__init__(self, rcfile=rcfile, rcbase=rcbase, env=env)
+
+        # renew output?
+        renew = self.GetSetting("renew", totype="bool")
+
+        # table file to be written:
+        lst_file = self.GetSetting("output.file")
+        # evaluate current time:
+        lst_file = datetime.datetime.now().strftime(lst_file)
+
+        # create?
+        if (not os.path.isfile(lst_file)) or renew:
+            # info ..
+            logging.info( f"{indent}create %s ..." % lst_file)
+
+            # initiallize for (re)creation:
+            listing = cso_file.CSO_Listing()
+            
+            # table with all available files:
+            listfile_all = self.GetSetting("all.file")
+            # evaluate time?
+            filedate = self.GetSetting( "all.filedate", totype="datetime", default=datetime.datetime.now() )
+            listfile_all = filedate.strftime(listfile_all)
+            # read:
+            listing_all = cso_file.CSO_Listing(listfile_all)
+            
+            # table with currently already available files:
+            listfile_curr = self.GetSetting("curr.file")
+            # evaluate time?
+            filedate = self.GetSetting( "curr.filedate", totype="datetime", default=datetime.datetime.now() )
+            listfile_curr = filedate.strftime(listfile_curr)
+            # read:
+            listing_curr = cso_file.CSO_Listing(listfile_curr)
+            
+            # extract orbits:
+            orbits = listing_all.GetValues( "orbit" ).unique()
+            # info ..
+            logging.info( f"{indent}found {len(orbits)} unique orbit numbers ..." )
+
+            # list of ';' seperated selection expression:
+            #     (%{processor_version} == '020400') & (%{processing} == 'RPRO') ; ...
+            selection_expr = self.GetSetting("selection")
+            # info ..
+            logging.info(f"{indent}selection criteria (first with matching orbit is used):")
+            for expr in selection_expr.split(";") :
+                logging.info(f"{indent}  {expr.strip()}")
+            # endif
+            
+            # info ..
+            logging.info( f"{indent}loop over available orbits ..." )
+            # loop:
+            for orbit in orbits :
+                # info ..
+                logging.info( f"{indent}  orbit '{orbit}' ..." )
+
+                # selection based on orbit and filter expression;
+                # returns None if no records are found:
+                xlst = listing_all.Select( orbit=orbit, expr=selection_expr, indent="    " )
+                # nothing selected?
+                if len(xlst) == 0 : continue
+
+                # loop over selected records:
+                for irec in range(len(xlst)):
+                    # current:
+                    rec = xlst.GetRecord(irec)
+                    ## info ..
+                    #logging.info( f"{indent}      {fname}" )
+                    # check if already available:
+                    if rec["filename"] in listing_curr :
+                        # info ...
+                        logging.info( f"{indent}    file already present ..." )
+                    else :
+                        # info ...
+                        logging.info( f"{indent}    file not present yet, add to list ..." )
+                        # add record to list:
+                        listing.UpdateRecord( rec["filename"], rec )
+                    #endif
+                #endfor
+
+                # testing ...
+                #break
+                #if len(listing) > 0 :
+                #    logging.warning(f"BREAK!")
+                #    break
+                ##endif
+            #endfor
+            
+            # save:
+            listing.Save(lst_file, indent= f"{indent}  ")
+
+        else:
+            # info ..
+            logging.info( f"{indent}keep %s ..." % lst_file)
+        # endif  # renew
+
+        # info ...
+        logging.info( f"{indent}")
+        logging.info( f"{indent}** end missing")
+        logging.info( f"{indent}")
+
+    # enddef __init__
+
+
+# endclass CSO_ColHubMirror_Missing
+
+########################################################################
+###
+### end
+###
+########################################################################
diff --git a/py/cso_file.py b/py/cso_file.py
index e926dbdd41bb094328836079742fde57ae3ee758..ca376d808221226bd38adfd2cc44d4e82812645e 100644
--- a/py/cso_file.py
+++ b/py/cso_file.py
@@ -21,7 +21,10 @@
 #   Do not pack coordinates. Updated comment.
 #
 # 2024-08, Arjo Segers
-#   Updated formatting.
+# Updated formatting.
+#
+# 2025-01, Arjo Segers
+#   Extened CSO_Listing class with selection and other methods.
 #
 
 ########################################################################
@@ -1209,15 +1212,13 @@ class CSO_Listing(object):
         2007/06/RAL-IASI-CH4_20070601T022359.nc;2007-06-01 02:23:59.512000000;2007-06-01 04:05:57.328000000
         ...
 
-    Arguments:
+    Optional arguments:
 
-    * ``filename`` : listing file, content is read if this file is already present unless ``renew==True`` ;
-      if ``exist==True`` the file should exist
-    * ``renew`` : (optinal) if ``True``, an existing file is ignored
+    * ``filename`` : listing file read into table
 
     """
 
-    def __init__(self, filename, exist=False, renew=False, indent=""):
+    def __init__(self, filename=None, indent=""):
         """
         Initialize empty table or read existing.
         """
@@ -1226,31 +1227,25 @@ class CSO_Listing(object):
         import os
         import pandas
 
-        # store:
-        self.filename = filename
-        # base path:
-        self.dirname = os.path.dirname(self.filename)
-
         # csv style:
         self.sep = ";"
         # head for index column:
         self.index_label = "filename"
+        
+        # read?
+        if filename is not None :
 
-        # check ..
-        if exist:
+            # check ..
             if not os.path.isfile(filename):
                 logging.error("listing file not found: %s" % filename)
                 raise Exception
             # endif
-        # endif
-
-        # already present?
-        if os.path.isfile(filename) and (not renew):
+        
             # info ...
-            logging.info(indent + "read listing %s ..." % self.filename)
+            logging.info(f"{indent} read listing {filename} ...")
             # read:
             self.df = pandas.read_csv(
-                self.filename,
+                filename,
                 sep=self.sep,
                 index_col=self.index_label,
                 parse_dates=["start_time", "end_time"],
@@ -1267,15 +1262,25 @@ class CSO_Listing(object):
 
     # *
 
-    def Close(self, indent=""):
+    def Save(self, filename, indent=""):
         """
         Write table to file.
         """
-
+        
         # info ...
-        logging.info(indent + "save listing %s ..." % self.filename)
-        # save:
-        self.df.to_csv(self.filename, sep=self.sep, index_label=self.index_label)
+        logging.info(f"{indent}save listing {filename} ...")
+
+        # create directory if needed:
+        CheckDir( filename )
+
+        # write all columns:
+        columns = list(self.df.keys())
+        # index only once ..
+        if self.index_label in columns :
+            columns.remove(self.index_label)
+
+        # save, also write the index column:
+        self.df.to_csv(filename, sep=self.sep, columns=columns, index_label=self.index_label)
 
     # enddef Close
 
@@ -1309,6 +1314,23 @@ class CSO_Listing(object):
 
     # *
 
+    def GetValues(self, name):
+        """
+        Return :py:class:`pandas.Series` object with all values for provided column ``name``.
+        """
+
+        # check ..
+        if name not in self.df.keys() :
+            logging.error( f"column '{name}' not found in: {self.filename}" )
+            raise Exception
+        #endif
+        # extract:
+        return self.df[name]
+
+    # enddef GetRecord
+
+    # *
+
     def __contains__(self, key):
         """
         Returns True if key is in the table index.
@@ -1320,6 +1342,17 @@ class CSO_Listing(object):
 
     # *
 
+    def keys(self):
+        """
+        Returns list of column names.
+        """
+
+        return self.df.keys()
+
+    # enddef keys
+
+    # *
+
     def Cleanup(self, indent=""):
         """
         Remove records from table if filename is not present anymore.
@@ -1423,9 +1456,9 @@ class CSO_Listing(object):
 
     # *
 
-    def Select(self, tr=None, method="overlap"):
+    def Select(self, tr=None, method="overlap", expr=None, blacklist=[], indent="", **kwargs ):
         """
-        Return dataframe with selected records.
+        Return :py:class:`CSO_Listing` objects with selection of records.
 
         Optional arguments:
 
@@ -1435,13 +1468,28 @@ class CSO_Listing(object):
           * ``method='overlap'`` (default) : select records that have pixels overlapping with interval
           * ``method='middle'`` : select pixels with the middle of ``start_time`` and ``end_time``
             within the inerval ``(t1,t2]``
+            
+        * ``name=value`` arguments select records based on column values
+        
+        * The exprssion ``expr`` provides a list of ';'-seperated selection expressions
+          with templates ``%{..}`` for the column names::
+        
+                (%{processor_version} == '020400') & (%{processing} == 'RPRO') ; ...
+                
+          This is evaluted after the previously described selections.
+          The result should be None or exactly one record.
+          Eventually skip files in ``blacklists``.
+
         """
 
         # modules:
+        import os
         import pandas
 
         # init result with entire dataset:
         df = self.df
+        
+        # *
 
         # time range specified?
         if tr is not None:
@@ -1463,9 +1511,103 @@ class CSO_Listing(object):
                 raise Exception
             # endif
         # endif
+        
+        # *
+        
+        # other selections:
+        for key,value in kwargs.items():
+            # check ..
+            if key not in df.keys():
+                logging.error( f"key '{key}' not defined in listing: {self.filename}" )
+                raise Exception
+            #endif
+            # select:
+            df = df[ df[key] == value ]
+        #endfor
+        
+        # *
+        
+        # evaluate selection expression?
+        if expr is not None :
+            # replace templates:
+            for key in self.df.keys():
+                expr = expr.replace("%{" + key + "}", "xrec['" + key + "']")
+            # endfor
+            # split:
+            selections = expr.split(";")
+
+            # storage for status label: "selected", "blacklisted", ...
+            filestatus = {}
+            # no match yet ..
+            seleted = []
+            # loop over selection criteria,
+            # this should give either none or a single file:
+            for selection in selections:
+                # make empty again:
+                selected = []
+                # loop over records:
+                for indx, xrec in df.iterrows():
+                    # skip?
+                    if os.path.basename(indx) in blacklist:
+                        filestatus[indx] = "blacklisted"
+                        continue
+                    # endif
+                    # evaluate expression including 'xrec[key]' values:
+                    if eval(selection):
+                        selected.append(indx)
+                        filestatus[indx] = "selected"
+                        rec = xrec
+                    # endif
+                # endfor # records
+                # exactly one? then leave:
+                if len(selected) == 1:
+                    break
+                elif len(selected) > 1:
+                    logging.error( f"found more than one record matching selection: {selection}" )
+                    for fname in selected:
+                       logging.error(f"  {fname}")
+                    # endfor
+                    raise Exception
+                # endif  # number found
+            # endfor # selection criteria
+
+            # info ...
+            logging.info(f"{indent}available records(s):")
+            # loop:
+            for fname, row in df.iterrows():
+                line = fname
+                if fname in filestatus.keys():
+                    line = line + " [" + filestatus[fname] + "]"
+                logging.info(f"{indent}  {line}")
+            # endfor
 
+            # no match?
+            if len(selected) == 0:
+                # info ...
+                logging.warning("    no match with any selection criterium ...")
+                ## degug:
+                # for selection in selections :
+                #    logging.warning( '    %s' % selection.strip() )
+                # logging.warning( '  record:' )
+                # for key in rec.keys() :
+                #    logging.warning( '    "%s" : "%s"' % (key,rec[key]) )
+                # create empty dataframe as result:
+                df = pandas.DataFrame(columns=df.columns)
+            else :
+                # extract selected record:
+                df = df.loc[[selected[0]]]
+            #endif
+        
+        #endif
+        
+        # *
+        
+        # return as listing:
+        lst = CSO_Listing()
+        lst.df = df
+        
         # ok
-        return df
+        return lst
 
     # enddef Select
 
@@ -1492,11 +1634,27 @@ class CSO_Listing(object):
             self.df = pandas.concat((self.df, xdf.set_index(self.index_label)))
         else:
             # append:
-            self.df = pandas.concat((self.df, lst.df))
+            if len(self.df) == 0 :
+                self.df = lst.df
+            else :
+                self.df = pandas.concat((self.df, lst.df))
+            #endif
         # endif
 
     # enddef Append
+    
+    # *
+    
+    def Sort(self,by="filename"):
+    
+        """
+        Sort listing table by filename or other key.
+        """
 
+        # sort inplace:
+        self.df.sort_values(by, inplace=True)
+        
+    #endef Sort
 
 # endclass CSO_Listing
 
diff --git a/py/cso_s5p.py b/py/cso_s5p.py
index 6dd1d3250173e1ac65f4f6ac7524edd3b9018aad..fbdd8faa9d9ffae6dc2811550f075d2ec0dd5f49 100644
--- a/py/cso_s5p.py
+++ b/py/cso_s5p.py
@@ -54,6 +54,9 @@
 #   Fixed replacement of units for special processing 'square_sum'.
 #   Fixed check on inquire filedates in case of multiple inquire files.
 #
+# 2025-01, Arjo Segers
+#   Use updated CSO_Listing class.
+#
 
 
 ########################################################################
@@ -2732,7 +2735,7 @@ class CSO_S5p_Convert(utopya.UtopyaRc):
             raise Exception
         # endif
         # init storage:
-        dfs = []
+        listing = cso_file.CSO_Listing()
         # loop:
         for ifile in range(len(filename__templates)):
             # current:
@@ -2746,31 +2749,16 @@ class CSO_S5p_Convert(utopya.UtopyaRc):
             # endif
             # expand time templates
             filename = t0.strftime(filename__template)
-            # check ..
-            if not os.path.isfile(filename):
-                logging.error("inquire table not found: %s" % filename)
-                raise Exception
-            # endif
-            # info ..
-            logging.info(f"{indent}read inquire table: %s" % filename)
             # read:
-            dfs.append(
-                pandas.read_csv(
-                    filename,
-                    sep=";",
-                    skip_blank_lines=True,
-                    parse_dates=["start_time", "end_time"],
-                    dtype="str",
-                )
-            )
+            lst = cso_file.CSO_Listing( filename )
+            # add:
+            listing.Append( lst )
         # endfor # filenames
-        # combine:
-        df = pandas.concat(dfs)
         # sort by filename:
-        df = df.sort_values("filename")
+        listing.Sort()
 
         # info ...
-        logging.info(f"{indent}number of files : %i" % len(df))
+        logging.info(f"{indent}number of files : %i" % len(listing))
 
         ## selected proecessings:
         # processings = self.GetSetting( 'processings' ).split()
@@ -2779,18 +2767,11 @@ class CSO_S5p_Convert(utopya.UtopyaRc):
 
         # list of ';' seperated selection expression:
         #     (%{processor_version} == '020400') & (%{processing} == 'RPRO') ; ...
-        line = self.GetSetting("selection")
-        # replace templates:
-        #     (xrec['processor_version'] == '020400') & (xrec['processing'] == 'RPRO') ; ...
-        for key in df.keys():
-            line = line.replace("%{" + key + "}", "xrec['" + key + "']")
-        # endfor
-        # split:
-        selections = line.split(";")
+        selection_expr = self.GetSetting("selection")
         # info ..
         logging.info("selection criteria (first with matching orbit is used):")
-        for selection in selections:
-            logging.info("  %s" % selection.strip())
+        for expr in selection_expr.split(";"):
+            logging.info(f"  {expr.strip()}" )
         # endif
 
         # skip some?
@@ -2822,12 +2803,12 @@ class CSO_S5p_Convert(utopya.UtopyaRc):
         complevel = self.GetSetting("output.complevel", "int")
 
         # select records with start time inside time range:
-        xdf = df[(df["start_time"] >= t1) & (df["start_time"] <= t2)]
+        xlst = listing.Select( tr=(t1,t2) )
         # info ..
-        logging.info(f"{indent}found %i orbits with overlap of time range .." % len(xdf))
+        logging.info(f"{indent}found {len(xlst)} orbits with overlap of time range .." )
 
         # oribit labels:
-        orbits = xdf["orbit"].unique()
+        orbits = xlst.GetValues("orbit").unique()
 
         # no download initialized yet:
         downloader = None
@@ -2839,70 +2820,14 @@ class CSO_S5p_Convert(utopya.UtopyaRc):
             # info ...
             logging.info(indent + '  orbit "%s" ...' % orbit)
 
-            # search for other records for same orbit:
-            odf = xdf[xdf["orbit"] == orbit]
-
-            # storage for status label: "selected", "blacklisted", ...
-            filestatus = {}
-            # no match yet ..
-            seleted = []
-            # loop over selection criteria,
-            # this should give either none or a single file:
-            for selection in selections:
-                # make empty again:
-                selected = []
-                # loop over records:
-                for indx, xrec in odf.iterrows():
-                    # skip?
-                    if os.path.basename(xrec["filename"]) in blacklist:
-                        filestatus[xrec["filename"]] = "blacklisted"
-                        continue
-                    # endif
-                    # evaluate expression including 'xrec[key]' values:
-                    if eval(selection):
-                        selected.append(xrec["filename"])
-                        filestatus[xrec["filename"]] = "selected"
-                        rec = xrec
-                    # endif
-                # endfor # records
-                # exactly one? then leave:
-                if len(selected) == 1:
-                    break
-                elif len(selected) > 1:
-                    logging.error(
-                        "found more than one orbit file matching selection: %s" % selection
-                    )
-                    for fname in selected:
-                        logging.error("  %s" % fname)
-                    # endfor
-                    raise Exception
-                # endif  # number found
-            # endfor # selection criteria
-
-            # info ...
-            logging.info(f"{indent}    available file(s):")
-            # loop:
-            for fname in odf["filename"]:
-                line = fname
-                if fname in filestatus.keys():
-                    line = line + " [" + filestatus[fname] + "]"
-                logging.info(f"{indent}      " + line)
-            # endfor
-
-            # no match?
-            if len(selected) == 0:
-                # info ...
-                logging.warning("    no match with any selection criterium; next orbit ...")
-                ## degug:
-                # for selection in selections :
-                #    logging.warning( '    %s' % selection.strip() )
-                # logging.warning( '  record:' )
-                # for key in rec.keys() :
-                #    logging.warning( '    "%s" : "%s"' % (key,rec[key]) )
-                # next orbit:
+            # select single orbit matching expression:
+            odf = xlst.Select( orbit=orbit, expr=selection_expr, blacklist=blacklist, indent=f"    " )
+            # no orbit found? next:
+            if len(odf) == 0 :
                 continue
-            # endif
-
+            # selected record:
+            rec = odf.GetRecord(0)
+            
             # start time of orbit:
             t0 = rec["start_time"]
 
@@ -3018,68 +2943,82 @@ class CSO_S5p_Convert(utopya.UtopyaRc):
             if create:
                 # keep list of downloaded files:
                 downloads = []
+                
+                # source location, either url or local mirror:
+                href = rec["href"]
+                # local file?
+                if os.path.isfile(href):
 
-                # input dir:
-                input_dir = t0.strftime(input_dir__template)
-                # replace templates:
-                for key in rec.keys():
-                    if type(rec[key]) == str:
-                        input_dir = input_dir.replace("%{" + key + "}", rec[key])
-                    # endif
-                # endfor
-                # full path:
-                input_file = os.path.join(input_dir, rec["filename"])
+                    # this is the input file:
+                    input_file = href
+                    # info ..
+                    logging.info("    input file: %s" % input_file)
+
+                else:
+
+                    # input dir:
+                    input_dir = t0.strftime(input_dir__template)
+                    # replace templates:
+                    for key in rec.keys():
+                        if type(rec[key]) == str:
+                            input_dir = input_dir.replace("%{" + key + "}", rec[key])
+                        # endif
+                    # endfor
+                    # full path:
+                    input_file = os.path.join(input_dir, rec["filename"])
 
-                # info ..
-                logging.info("    input file: %s" % input_file)
-                # check ..
-                if not os.path.isfile(input_file):
                     # info ..
-                    logging.info("      not present yet, download ...")
-                    # download url:
-                    href = rec["href"]
-                    # initialize download?
-                    if downloader is None:
-                        # init downloader based on url:
-                        if "dataspace.copernicus.eu" in href:
-                            # download from Copernicus DataSpace:
-                            downloader = cso_dataspace.CSO_DataSpace_Downloader()
-                        #
-                        elif "s5p-pal.com" in href:
-                            # download from PAL:
-                            downloader = cso_pal.CSO_PAL_Downloader()
-                        #
-                        else:
-                            logging.error("no downloader class defined for url: {href}")
-                            raise Exception
+                    logging.info("    input file: %s" % input_file)
+                    # check ..
+                    if not os.path.isfile(input_file):
+                        # info ..
+                        logging.info("      not present yet, download ...")
+                        # download url:
+                        href = rec["href"]
+                        # initialize download?
+                        if downloader is None:
+                            # init downloader based on url:
+                            if "dataspace.copernicus.eu" in href:
+                                # download from Copernicus DataSpace:
+                                downloader = cso_dataspace.CSO_DataSpace_Downloader()
+                            #
+                            elif "s5p-pal.com" in href:
+                                # download from PAL:
+                                downloader = cso_pal.CSO_PAL_Downloader()
+                            #
+                            else:
+                                logging.error(f"no downloader class defined for url: {href}")
+                                raise Exception
+                            # endif
                         # endif
+                        # download ...
+                        downloader.DownloadFile(href, input_file, indent="        ")
+                        # store name:
+                        downloads.append(input_file)
                     # endif
-                    # download ...
-                    downloader.DownloadFile(href, input_file, indent="        ")
-                    # store name:
-                    downloads.append(input_file)
-                # endif
 
-                # download might have failed ..
-                if not os.path.isfile(input_file):
-                    # write error file or raise error?
-                    if with_error_files:
-                        # info ..
-                        logging.warning(f"{indent}      missing input file, write error file ...")
-                        # write error file:
-                        with open(output_errfile, "w") as f:
-                            f.write("missing file: %s\n" % input_file)
-                        # endwith
-                        # next:
-                        continue
-                    else:
-                        # info ..
-                        logging.error(f"missing input file")
-                        logging.error(f"  {input_file}")
-                        logging.error(f"enable creation of *error files* to not break on this")
-                        raise Exception
+                    # download might have failed ..
+                    if not os.path.isfile(input_file):
+                        # write error file or raise error?
+                        if with_error_files:
+                            # info ..
+                            logging.warning(f"{indent}      missing input file, write error file ...")
+                            # write error file:
+                            with open(output_errfile, "w") as f:
+                                f.write("missing file: %s\n" % input_file)
+                            # endwith
+                            # next:
+                            continue
+                        else:
+                            # info ..
+                            logging.error(f"missing input file")
+                            logging.error(f"  {input_file}")
+                            logging.error(f"enable creation of *error files* to not break on this")
+                            raise Exception
+                        # endif
                     # endif
-                # endif
+                    
+                # endif  # local mirror or remote source file
 
                 # info ...
                 logging.info(f"{indent}    open ...")
@@ -3328,7 +3267,7 @@ class CSO_S5p_Download(utopya.UtopyaRc):
         # combine:
         df = pandas.concat(dfs)
         # sort by filename:
-        df = df.sort_values("filename")
+        df.sort_values("filename", inplace=True)
 
         # info ...
         logging.info(f"{indent}number of files : %i" % len(df))