Add flash age compositor for li instruments

satpy/composites/lightning.py

@@ -0,0 +1,108 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright (c) 2019 Satpy developers
+#
+# This file is part of satpy.
+#
+# satpy is free software: you can redistribute it and/or modify it under the
+# terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
+#
+# satpy is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# satpy.  If not, see <http://www.gnu.org/licenses/>.
+"""Composite classes for the LI instrument."""
+
+import logging
+
+import numpy as np
+import xarray as xr
+
+from satpy.composites import CompositeBase
+
+LOG = logging.getLogger(__name__)
+
+
+class LightningTimeCompositor(CompositeBase):
+      """Class used to create the flash_age compositor usefull for lighting event visualisation.
+
+      The datas used are dates related to the lightning event that should be normalised between
+      0 and 1. The value 1 corresponds to the latest lightning event and the value 0 corresponds
+      to the latest lightning event - time_range. The time_range is defined in the satpy/etc/composites/li.yaml
+      and is in minutes.
+      """
+      def __init__(self, name, prerequisites=None, optional_prerequisites=None, **kwargs):
+          """Initialisation of the class."""
+          super().__init__(name, prerequisites, optional_prerequisites, **kwargs)
+          # Get the time_range which is in minute
+          self.time_range = self.attrs["time_range"]
+          self.standard_name = self.attrs["standard_name"]
+          self.reference_time_attr = self.attrs["reference_time"]
+
+
+      def _normalize_time(self, data:xr.DataArray, attrs:dict) -> xr.DataArray:
+          """Normalize the time in the range between [end_time, end_time - time_range].
+
+          The range of the normalised data is between 0 and 1 where 0 corresponds to the date end_time - time_range
+          and 1 to the end_time. Where end_times represent the latest lightning event and time_range is the range of
+          time you want to see the event.The dates that are earlier to end_time - time_range are removed.
+
+          Args:
+              data (xr.DataArray): datas containing dates to be normalised
+              attrs (dict): Attributes suited to the flash_age composite
+
+          Returns:
+              xr.DataArray: Normalised time
+          """
+          # Compute the maximum time value
+          end_time = np.array(np.datetime64(data.attrs[self.reference_time_attr]))
+          # Compute the minimum time value based on the time range
+          begin_time = end_time - np.timedelta64(self.time_range, "m")
+          # Drop values that are bellow begin_time
+          condition_time = data >= begin_time
+          condition_time_computed = condition_time.compute()
+          data = data.where(condition_time_computed, drop=True)
+          # exit if data is empty afer filtering
+          if data.size == 0 :
+              LOG.error(f"All the flash_age events happened before {begin_time}")
+              raise ValueError(f"Invalid data: data size is zero. All flash_age "
+                f"events occurred before the specified start time ({begin_time})."
+                )
+          # Normalize the time values
+          normalized_data = (data - begin_time) / (end_time - begin_time)
+          # Ensure the result is still an xarray.DataArray
+          return xr.DataArray(normalized_data, dims=data.dims, coords=data.coords, attrs=attrs)
+
+
+      @staticmethod
+      def _update_missing_metadata(existing_attrs, new_attrs):
+          for key, val in new_attrs.items():
+              if key not in existing_attrs and val is not None:
+                  existing_attrs[key] = val
+
+      def _redefine_metadata(self,attrs:dict)->dict:
+          """Modify the standard_name and name metadatas.
+
+          Args:
+              attrs (dict): data's attributes
+
+          Returns:
+              dict: atualised attributes
+          """
+          attrs["name"] = self.standard_name
+          attrs["standard_name"] = self.standard_name
+          # Attributes to describe the values range
+          return attrs
+
+
+      def __call__(self,projectables, nonprojectables=None, **attrs):
+          """Normalise the dates."""
+          data = projectables[0]
+          new_attrs = data.attrs.copy()
+          self._update_missing_metadata(new_attrs, attrs)
+          new_attrs = self._redefine_metadata(new_attrs)
+          return self._normalize_time(data, new_attrs)

satpy/etc/composites/fci.yaml

@@ -1,17 +1,17 @@
 sensor_name: visir/fci
 
 composites:
-### L2
+  ### L2
   binary_cloud_mask:
     # This will set all clear pixels to '0', all pixels with cloudy features (meteorological/dust/ash clouds) to '1' and
     # missing/undefined pixels to 'nan'. This can be used for the official EUMETSAT cloud mask product (CLM).
     compositor: !!python/name:satpy.composites.CategoricalDataCompositor
     prerequisites:
-      - name: 'cloud_state'
-    lut: [ .nan, 0, 1, 1, 1, 1, 1, 1, 0, .nan ]
+      - name: "cloud_state"
+    lut: [.nan, 0, 1, 1, 1, 1, 1, 1, 0, .nan]
     standard_name: binary_cloud_mask
 
-### Night Layers
+  ### Night Layers
   night_ir105:
     compositor: !!python/name:satpy.composites.SingleBandCompositor
     prerequisites:
@@ -41,7 +41,7 @@ composites:
       - night_ir_alpha
       - _night_background_hires
 
-### Green Corrections
+  ### Green Corrections
   ndvi_hybrid_green:
     description: >
       The FCI green band at 0.51 µm deliberately misses the chlorophyll band, such that
@@ -58,7 +58,7 @@ composites:
       - name: vis_06
         modifiers: [sunz_corrected, rayleigh_corrected, sunz_reduced]
       - name: vis_08
-        modifiers: [sunz_corrected, sunz_reduced ]
+        modifiers: [sunz_corrected, sunz_reduced]
     standard_name: toa_bidirectional_reflectance
 
   ndvi_hybrid_green_raw:
@@ -76,18 +76,18 @@ composites:
   ndvi_hybrid_green_fully_sunzencorrected:
     description: Same as ndvi_hybrid_green, but without Sun-zenith reduction
     compositor: !!python/name:satpy.composites.spectral.NDVIHybridGreen
-    limits: [ 0.15, 0.05 ]
+    limits: [0.15, 0.05]
     strength: 3.0
     prerequisites:
       - name: vis_05
-        modifiers: [ sunz_corrected, rayleigh_corrected ]
+        modifiers: [sunz_corrected, rayleigh_corrected]
       - name: vis_06
-        modifiers: [ sunz_corrected, rayleigh_corrected ]
+        modifiers: [sunz_corrected, rayleigh_corrected]
       - name: vis_08
-        modifiers: [ sunz_corrected ]
+        modifiers: [sunz_corrected]
     standard_name: toa_bidirectional_reflectance
 
-### True Color
+  ### True Color
   true_color:
     compositor: !!python/name:satpy.composites.SelfSharpenedRGB
     description: >
@@ -190,7 +190,7 @@ composites:
       - name: vis_04
     standard_name: true_color_reproduction_color_stretch
 
-### True Color with LI lightning
+  ### True Color with LI lightning
 
   true_color_with_night_ir105_acc_flash:
     compositor: !!python/name:satpy.composites.BackgroundCompositor
@@ -227,74 +227,81 @@ composites:
       - group_radiance_alpha
       - true_color_with_night_ir105
 
-### GeoColor
+  true_color_with_night_ir105_flash_age:
+    compositor: !!python/name:satpy.composites.BackgroundCompositor
+    standard_name: imager_with_lightning
+    prerequisites:
+      - flash_age
+      - true_color_with_night_ir105
+
+  ### GeoColor
   geo_color:
-   compositor: !!python/name:satpy.composites.DayNightCompositor
-   description: >
-     GeoColor is a multi-layer blended RGB composite where the day-time part of the image is represented by true
-     color imagery and the nighttime part of the image by a three layer vertically blended stack composed of a
-     high-level cloud layer (single IR window channel), a low-level cloud layer (IR split window) and a static
-     surface terrain layer with city lights (NASA Black Marble).
-   references:
-     Research Article: https://journals.ametsoc.org/view/journals/atot/37/3/JTECH-D-19-0134.1.xml
-   lim_low: 78
-   lim_high: 88
-   standard_name: geo_color_day_night_blend
-   prerequisites:
-     - true_color
-     - geo_color_night
+    compositor: !!python/name:satpy.composites.DayNightCompositor
+    description: >
+      GeoColor is a multi-layer blended RGB composite where the day-time part of the image is represented by true
+      color imagery and the nighttime part of the image by a three layer vertically blended stack composed of a
+      high-level cloud layer (single IR window channel), a low-level cloud layer (IR split window) and a static
+      surface terrain layer with city lights (NASA Black Marble).
+    references:
+      Research Article: https://journals.ametsoc.org/view/journals/atot/37/3/JTECH-D-19-0134.1.xml
+    lim_low: 78
+    lim_high: 88
+    standard_name: geo_color_day_night_blend
+    prerequisites:
+      - true_color
+      - geo_color_night
 
   geo_color_high_clouds:
-   standard_name: geo_color_high_clouds
-   compositor: !!python/name:satpy.composites.HighCloudCompositor
-   prerequisites:
-     - name: ir_105
+    standard_name: geo_color_high_clouds
+    compositor: !!python/name:satpy.composites.HighCloudCompositor
+    prerequisites:
+      - name: ir_105
 
   geo_color_low_clouds:
-   standard_name: geo_color_low_clouds
-   compositor: !!python/name:satpy.composites.LowCloudCompositor
-   values_water: 0
-   values_land: 100
-   range_water: [0.0, 4.0]
-   range_land: [1.5, 4.0]
-   prerequisites:
-     - compositor: !!python/name:satpy.composites.DifferenceCompositor
-       prerequisites:
-         - name: ir_105
-         - name: ir_38
-     - name: ir_105
-     - compositor: !!python/name:satpy.composites.StaticImageCompositor
-       standard_name: land_water_mask
-       url: "https://zenodo.org/records/10076199/files/gshhs_land_water_mask_3km_i.tif"
-       known_hash: "sha256:96df83c57416217e191f95dde3d3c1ce0373a8fc220e929228873db246ca3569"
+    standard_name: geo_color_low_clouds
+    compositor: !!python/name:satpy.composites.LowCloudCompositor
+    values_water: 0
+    values_land: 100
+    range_water: [0.0, 4.0]
+    range_land: [1.5, 4.0]
+    prerequisites:
+      - compositor: !!python/name:satpy.composites.DifferenceCompositor
+        prerequisites:
+          - name: ir_105
+          - name: ir_38
+      - name: ir_105
+      - compositor: !!python/name:satpy.composites.StaticImageCompositor
+        standard_name: land_water_mask
+        url: "https://zenodo.org/records/10076199/files/gshhs_land_water_mask_3km_i.tif"
+        known_hash: "sha256:96df83c57416217e191f95dde3d3c1ce0373a8fc220e929228873db246ca3569"
 
   geo_color_background_with_low_clouds:
-   compositor: !!python/name:satpy.composites.BackgroundCompositor
-   standard_name: night_ir_with_background
-   prerequisites:
-     - geo_color_low_clouds
-     - _night_background_hires
+    compositor: !!python/name:satpy.composites.BackgroundCompositor
+    standard_name: night_ir_with_background
+    prerequisites:
+      - geo_color_low_clouds
+      - _night_background_hires
 
   geo_color_night:
-   compositor: !!python/name:satpy.composites.BackgroundCompositor
-   standard_name: night_ir_with_background
-   prerequisites:
-     - geo_color_high_clouds
-     - geo_color_background_with_low_clouds
+    compositor: !!python/name:satpy.composites.BackgroundCompositor
+    standard_name: night_ir_with_background
+    prerequisites:
+      - geo_color_high_clouds
+      - geo_color_background_with_low_clouds
 
-### IR-Sandwich
+  ### IR-Sandwich
   ir_sandwich:
     compositor: !!python/name:satpy.composites.SandwichCompositor
     standard_name: ir_sandwich
     prerequisites:
-      - name: 'vis_06'
-        modifiers: [ sunz_corrected ]
+      - name: "vis_06"
+        modifiers: [sunz_corrected]
       - name: colorized_ir_clouds
 
   colorized_ir_clouds:
     compositor: !!python/name:satpy.composites.SingleBandCompositor
     prerequisites:
-      - name: 'ir_105'
+      - name: "ir_105"
     standard_name: colorized_ir_clouds
 
   ir_sandwich_with_night_colorized_ir_clouds:
@@ -306,7 +313,7 @@ composites:
       - ir_sandwich
       - colorized_ir_clouds
 
-### other RGBs
+  ### other RGBs
   cloud_type:
     description: >
       Equal to cimss_cloud_type recipe, but with additional sunz_reducer modifier to avoid saturation at the terminator.
@@ -316,11 +323,11 @@ composites:
     compositor: !!python/name:satpy.composites.GenericCompositor
     prerequisites:
       - name: nir_13
-        modifiers: [ sunz_corrected, sunz_reduced ]
+        modifiers: [sunz_corrected, sunz_reduced]
       - name: vis_06
-        modifiers: [ sunz_corrected, sunz_reduced ]
+        modifiers: [sunz_corrected, sunz_reduced]
       - name: nir_16
-        modifiers: [ sunz_corrected, sunz_reduced ]
+        modifiers: [sunz_corrected, sunz_reduced]
     standard_name: cimss_cloud_type
 
   cloud_type_with_night_ir105:
@@ -416,10 +423,10 @@ composites:
       Recipe: https://resources.eumetrain.org/RGBguide/recipes/RGB_recipes.pdf
     compositor: !!python/name:satpy.composites.GenericCompositor
     prerequisites:
-    - name: vis_08
-      modifiers: [sunz_corrected]
-    - name: nir_16
-      modifiers: [sunz_corrected]
-    - name: ir_38
-      modifiers: [nir_reflectance]
+      - name: vis_08
+        modifiers: [sunz_corrected]
+      - name: nir_16
+        modifiers: [sunz_corrected]
+      - name: ir_38
+        modifiers: [nir_reflectance]
     standard_name: snow