diff --git a/satpy/composites/ahi.py b/satpy/composites/ahi.py
index 629f5388ed..34d7303022 100644
--- a/satpy/composites/ahi.py
+++ b/satpy/composites/ahi.py
@@ -24,149 +24,22 @@
 
 import logging
 
-import numpy as np
-from pyresample.geometry import AreaDefinition
-from satpy.composites import CompositeBase
-from satpy.dataset import Dataset
+from satpy.composites import GenericCompositor
 
 LOG = logging.getLogger(__name__)
 
 
-class GreenCorrector(CompositeBase):
+class GreenCorrector(GenericCompositor):
     """Corrector of the AHI green band to compensate for the deficit of
     chlorophyl signal.
     """
 
-    def __call__(self, projectables, optional_datasets=None, **info):
+    def __call__(self, projectables, optional_datasets=None, **attrs):
         """Boost vegetation effect thanks to NIR (0.8µm) band."""
 
-        (green, nir) = projectables
-
+        green, nir = self.check_areas(projectables)
         LOG.info('Boosting vegetation on green band')
 
-        proj = Dataset(green * 0.85 + nir * 0.15,
-                       copy=False,
-                       **green.info)
-        self.apply_modifier_info(green, proj)
-
-        return proj
-
-
-class Expander(CompositeBase):
-    """Expand the size of the composite.
-
-    Keyword Args:
-        factor (int): Repeat both dimensions by this number
-
-    """
-    def __call__(self, projectables, optional_datasets=None, **info):
-        factor = self.attrs.get('factor', 2)
-
-        (band,) = projectables
-
-        LOG.info('Expanding datasize by a factor %d.', factor)
-
-        proj = Dataset(
-            np.repeat(np.repeat(band, factor, axis=0), factor, axis=1),
-            copy=False, **band.info)
-
-        old_area = proj.info['area']
-        proj.info['area'] = AreaDefinition(old_area.area_id,
-                                           old_area.name,
-                                           old_area.proj_id,
-                                           old_area.proj_dict,
-                                           old_area.x_size * factor,
-                                           old_area.y_size * factor,
-                                           old_area.area_extent)
-        proj.info['resolution'] *= factor
-        self.apply_modifier_info(band, proj)
-        return proj
-
-
-class Reducer2(CompositeBase):
-    """Reduce the size of the composite."""
-
-    def __call__(self, projectables, optional_datasets=None, **info):
-        (band,) = projectables
-
-        factor = 2
-
-        LOG.info('Reducing datasize by a factor %d.', factor)
-
-        proj = band[::factor, ::factor]
-        # newshape = (band.shape[0] / factor, factor,
-        #            band.shape[1] / factor, factor)
-        # proj = Dataset(band.reshape(newshape).mean(axis=3).mean(axis=1),
-        #               copy=False, **band.info)
-
-        old_area = proj.attrs['area']
-        proj.attrs['area'] = AreaDefinition(old_area.area_id,
-                                            old_area.name,
-                                            old_area.proj_id,
-                                            old_area.proj_dict,
-                                            old_area.x_size / factor,
-                                            old_area.y_size / factor,
-                                            old_area.area_extent)
-        proj.attrs['resolution'] *= factor
-        self.apply_modifier_info(band, proj)
-        return proj
-
-
-class Reducer4(CompositeBase):
-    """Reduce the size of the composite."""
-
-    def __call__(self, projectables, optional_datasets=None, **info):
-        (band,) = projectables
-
-        factor = 4
-
-        LOG.info('Reducing datasize by a factor %d.', factor)
-
-        proj = band[::factor, ::factor]
-
-        # newshape = (band.shape[0] / factor, factor,
-        #            band.shape[1] / factor, factor)
-        # proj = Dataset(band.reshape(newshape).mean(axis=3).mean(axis=1),
-        #               copy=False, **band.info)
-
-        old_area = proj.attrs['area']
-        proj.attrs['area'] = AreaDefinition(old_area.area_id,
-                                            old_area.name,
-                                            old_area.proj_id,
-                                            old_area.proj_dict,
-                                            old_area.x_size / factor,
-                                            old_area.y_size / factor,
-                                            old_area.area_extent)
-        proj.attrs['resolution'] *= factor
-        self.apply_modifier_info(band, proj)
-        return proj
-
-
-class Reducer8(CompositeBase):
-    """Reduce the size of the composite."""
-
-    def __call__(self, projectables, optional_datasets=None, **info):
-        (band,) = projectables
-
-        factor = 8
-
-        LOG.info('Reducing datasize by a factor %d.', factor)
-
-        proj = band[::factor, ::factor]
-
-        # newshape = (band.shape[0] / factor, factor,
-        #            band.shape[1] / factor, factor)
-        # proj = Dataset(band.reshape(newshape).mean(axis=3).mean(axis=1),
-        #               copy=False, **band.info)
-
-        old_area = proj.attrs['area']
-        proj.attrs['area'] = AreaDefinition(old_area.area_id,
-                                            old_area.name,
-                                            old_area.proj_id,
-                                            old_area.proj_dict,
-                                            old_area.x_size / factor,
-                                            old_area.y_size / factor,
-                                            old_area.area_extent)
-        proj.attrs['resolution'] *= factor
-        self.apply_modifier_info(band, proj)
-        return proj
+        new_green = green * 0.85 + nir * 0.15
+        new_green.attrs = green.attrs.copy()
+        return super(GreenCorrector, self).__call__((new_green,), **attrs)
diff --git a/satpy/etc/composites/ahi.yaml b/satpy/etc/composites/ahi.yaml
index 80ad021dfb..f3255322d4 100644
--- a/satpy/etc/composites/ahi.yaml
+++ b/satpy/etc/composites/ahi.yaml
@@ -1,76 +1,33 @@
 sensor_name: visir/ahi
 
 modifiers:
-  reducer2:
-    compositor: !!python/name:satpy.composites.ahi.Reducer2
-
-  reducer4:
-    compositor: !!python/name:satpy.composites.ahi.Reducer4
-
-  vegetation_corrected:
-    compositor: !!python/name:satpy.composites.ahi.GreenCorrector
-    prerequisites:
-    - wavelength: 0.85
-
-  vegetation_corrected_reduced:
-    compositor: !!python/name:satpy.composites.ahi.GreenCorrector
-    prerequisites:
-    - wavelength: 0.85
-      modifiers: [reducer2,]
-
   rayleigh_corrected:
     compositor: !!python/name:satpy.composites.PSPRayleighReflectance
     atmosphere: us-standard
     aerosol_type: marine_clean_aerosol
     prerequisites:
     - wavelength: 0.65
-      modifiers: [reducer2, sunz_corrected]
-    optional_prerequisites:
-    - satellite_azimuth_angle
-    - satellite_zenith_angle
-    - solar_azimuth_angle
-    - solar_zenith_angle
-
-  rayleigh_corrected_reducedsize:
-    compositor: !!python/name:satpy.composites.PSPRayleighReflectance
-    atmosphere: us-standard
-    aerosol_type: marine_clean_aerosol
-    prerequisites:
-    - wavelength: 0.65
-      modifiers: [reducer4, sunz_corrected]
+      modifiers: [sunz_corrected]
     optional_prerequisites:
     - satellite_azimuth_angle
     - satellite_zenith_angle
     - solar_azimuth_angle
     - solar_zenith_angle
 
-  rayleigh_corrected_reducedsize_land:
-    compositor: !!python/name:satpy.composites.PSPRayleighReflectance
-    atmosphere: us-standard
-    aerosol_type: continental_average_aerosol
-    prerequisites:
-    - wavelength: 0.65
-      modifiers: [reducer4, sunz_corrected]
-    optional_prerequisites:
-    - satellite_azimuth_angle
-    - satellite_zenith_angle
-    - solar_azimuth_angle
-    - solar_zenith_angle
-
-  rayleigh_corrected_reducedsize_marine_tropical:
-    compositor: !!python/name:satpy.composites.PSPRayleighReflectance
-    atmosphere: us-standard
-    aerosol_type: marine_tropical_aerosol
+composites:
+  green:
+    compositor: !!python/name:satpy.composites.ahi.GreenCorrector
+    # FUTURE: Set a wavelength...see what happens. Dependency finding
+    #         probably wouldn't work.
     prerequisites:
-    - wavelength: 0.65
-      modifiers: [reducer4, sunz_corrected]
-    optional_prerequisites:
-    - satellite_azimuth_angle
-    - satellite_zenith_angle
-    - solar_azimuth_angle
-    - solar_zenith_angle
+    # should we be using the most corrected or least corrected inputs?
+    # what happens if something requests more modifiers on top of this?
+    - wavelength: 0.51
+      modifiers: [sunz_corrected]
+    - wavelength: 0.85
+      modifiers: [sunz_corrected]
+    standard_name: toa_bidirection_reflectance
 
-composites:
   overview:
     compositor: !!python/name:satpy.composites.GenericCompositor
     prerequisites:
@@ -79,90 +36,72 @@ composites:
     - 10.4
     standard_name: overview
 
-  true_color:
-    compositor: !!python/name:satpy.composites.GenericCompositor
-    prerequisites:
-    - wavelength: 0.65
-      modifiers: [reducer2, effective_solar_pathlength_corrected, rayleigh_corrected]
-    - wavelength: 0.51
-      modifiers: [vegetation_corrected, effective_solar_pathlength_corrected, rayleigh_corrected]
-    - wavelength: 0.46
-      modifiers: [effective_solar_pathlength_corrected, rayleigh_corrected]
-    standard_name: true_color
-
-  true_color_reducedsize:
-    compositor: !!python/name:satpy.composites.GenericCompositor
-    prerequisites:
-    - wavelength: 0.65
-      modifiers: [reducer4, effective_solar_pathlength_corrected,
-                  rayleigh_corrected_reducedsize]
-    - wavelength: 0.51
-      modifiers: [reducer2, vegetation_corrected_reduced, effective_solar_pathlength_corrected,
-                  rayleigh_corrected_reducedsize]
-    - wavelength: 0.46
-      modifiers: [reducer2, effective_solar_pathlength_corrected,
-                  rayleigh_corrected_reducedsize]
-    standard_name: true_color
-
-  true_color_reducedsize_land:
-    compositor: !!python/name:satpy.composites.GenericCompositor
+  natural:
+    compositor: !!python/name:satpy.composites.SelfSharpenedRGB
     prerequisites:
-    - wavelength: 0.65
-      modifiers: [reducer4, effective_solar_pathlength_corrected,
-                  rayleigh_corrected_reducedsize_land]
-    - wavelength: 0.51
-      modifiers: [reducer2, vegetation_corrected_reduced, effective_solar_pathlength_corrected,
-                  rayleigh_corrected_reducedsize_land]
-    - wavelength: 0.46
-      modifiers: [reducer2, effective_solar_pathlength_corrected,
-                  rayleigh_corrected_reducedsize_land]
-    standard_name: true_color
+    - wavelength: 1.63
+      modifiers: [sunz_corrected] #, rayleigh_corrected]
+    - wavelength: 0.85
+      modifiers: [sunz_corrected] #, rayleigh_corrected]
+    - wavelength: 0.635
+      modifiers: [sunz_corrected] #, rayleigh_corrected]
+    high_resolution_band: blue
+    standard_name: natural
 
-  true_color_reducedsize_marine_tropical:
-    compositor: !!python/name:satpy.composites.GenericCompositor
+  true_color:
+    compositor: !!python/name:satpy.composites.SelfSharpenedRGB
     prerequisites:
     - wavelength: 0.65
-      modifiers: [reducer4, effective_solar_pathlength_corrected,
-                  rayleigh_corrected_reducedsize_marine_tropical]
-    - wavelength: 0.51
-      modifiers: [reducer2, vegetation_corrected_reduced, effective_solar_pathlength_corrected,
-                  rayleigh_corrected_reducedsize_marine_tropical]
+      modifiers: [sunz_corrected]  #, rayleigh_corrected]
+    - name: green
     - wavelength: 0.46
-      modifiers: [reducer2, effective_solar_pathlength_corrected,
-                  rayleigh_corrected_reducedsize_marine_tropical]
+      modifiers: [sunz_corrected]  #, rayleigh_corrected]
+    high_resolution_band: red
     standard_name: true_color
 
-  true_color_norayleigh:
-    compositor: !!python/name:satpy.composites.GenericCompositor
-    prerequisites:
-    - wavelength: 0.65
-      modifiers: [reducer2, effective_solar_pathlength_corrected]
-    - wavelength: 0.51
-      modifiers: [vegetation_corrected, effective_solar_pathlength_corrected]
-    - wavelength: 0.46
-      modifiers: [effective_solar_pathlength_corrected]
-    standard_name: true_color
+#  true_color_reducedsize_land:
+#    compositor: !!python/name:satpy.composites.GenericCompositor
+#    prerequisites:
+#    - wavelength: 0.65
+#      modifiers: [reducer4, effective_solar_pathlength_corrected,
+#                  rayleigh_corrected_reducedsize_land]
+#    - wavelength: 0.51
+#      modifiers: [reducer2, vegetation_corrected_reduced, effective_solar_pathlength_corrected,
+#                  rayleigh_corrected_reducedsize_land]
+#    - wavelength: 0.46
+#      modifiers: [reducer2, effective_solar_pathlength_corrected,
+#                  rayleigh_corrected_reducedsize_land]
+#    standard_name: true_color
+#
+#  true_color_reducedsize_marine_tropical:
+#    compositor: !!python/name:satpy.composites.GenericCompositor
+#    prerequisites:
+#    - wavelength: 0.65
+#      modifiers: [reducer4, effective_solar_pathlength_corrected,
+#                  rayleigh_corrected_reducedsize_marine_tropical]
+#    - wavelength: 0.51
+#      modifiers: [reducer2, vegetation_corrected_reduced, effective_solar_pathlength_corrected,
+#                  rayleigh_corrected_reducedsize_marine_tropical]
+#    - wavelength: 0.46
+#      modifiers: [reducer2, effective_solar_pathlength_corrected,
+#                  rayleigh_corrected_reducedsize_marine_tropical]
+#    standard_name: true_color
 
   day_microphysics_eum:
     compositor: !!python/name:satpy.composites.GenericCompositor
     prerequisites:
     - wavelength: 0.86
-      modifiers: [reducer4, ]
     - wavelength: 3.9
-      modifiers: [nir_reflectance, reducer2]
+      modifiers: [nir_reflectance]
     - wavelength: 10.4
-      modifiers: [reducer2, ]
     standard_name: day_microphysics
 
   day_microphysics_ahi:
     compositor: !!python/name:satpy.composites.GenericCompositor
     prerequisites:
     - wavelength: 0.86
-      modifiers: [reducer4, ]
     - wavelength: 2.3
-      modifiers: [reducer2]
     - wavelength: 10.4
-      modifiers: [reducer2, ]
     standard_name: day_microphysics
 
   cloud_phase_distinction:
@@ -170,7 +109,6 @@ composites:
     prerequisites:
     - wavelength: 10.4
     - wavelength: 0.64
-      modifiers: [reducer4]
     - wavelength: 1.6
     standard_name: cloud_phase_distinction
 
@@ -200,8 +138,7 @@ composites:
   convection:
     compositor: !!python/name:satpy.composites.Convection
     prerequisites:
-    - wavelength: 0.635
-      modifiers: [reducer4]
+    - 0.635
     - 1.63
     - 3.75
     - 6.7
diff --git a/satpy/etc/readers/geocat.yaml b/satpy/etc/readers/geocat.yaml
index b9e0757462..f93a3d8524 100644
--- a/satpy/etc/readers/geocat.yaml
+++ b/satpy/etc/readers/geocat.yaml
@@ -1,5 +1,5 @@
 reader:
-  description: GEOCAT
+  description: CSPP Geo and GEOCAT file reader
   name: geocat
   reader: !!python/name:satpy.readers.geocat.GEOCATYAMLReader
   sensors: [abi, ahi, goes_imager]
@@ -11,9 +11,226 @@ file_types:
      - 'geocatL{processing_level:1d}.{platform_shortname}.{start_time:%Y%j.%H%M%S}.hdf'
      - 'geocatL{processing_level:1d}.{platform_shortname}.{start_time:%Y%j.%H%M%S}.nc'
      # Himawari 8 files:
-     - 'geocatL{processing_level:1d}.{platform_shortname}.{start_time:%Y%j.%H%M%S}.{sector_id}.{res_id}.hdf'
-     - 'geocatL{processing_level:1d}.{platform_shortname}.{start_time:%Y%j.%H%M%S}.{sector_id}.{res_id}.nc'
+     - 'geocatL2.{platform_shortname}.{start_time:%Y%j.%H%M%S}.{sector_id}.{res_id}.hdf'
+     - 'geocatL2.{platform_shortname}.{start_time:%Y%j.%H%M%S}.{sector_id}.{res_id}.nc'
      # GOES-16 ABI files:
      - 'geocatL{processing_level:1d}.{platform_shortname}.{sector_id}.{start_time:%Y%j.%H%M%S}.hdf'
      - 'geocatL{processing_level:1d}.{platform_shortname}.{sector_id}.{start_time:%Y%j.%H%M%S}.nc'
+  ahi_level1:
+    file_reader: !!python/name:satpy.readers.geocat.GEOCATFileHandler
+    file_patterns:
+     # we could use the H8 pattern above, but then the datasets listed below
+     # would always be "available"
+     - 'geocatL1.HIMAWARI-8.{start_time:%Y%j.%H%M%S}.{sector_id}.{res_id}.hdf'
+     - 'geocatL1.HIMAWARI-8.{start_time:%Y%j.%H%M%S}.{sector_id}.{res_id}.nc'
 
+datasets:
+  # AHI Level 1 Datasets (need to define here so wavelengths can be used)
+  B01:
+    name: B01
+    sensor: ahi
+    wavelength: [0.45,0.47,0.49]
+    calibration:
+      reflectance:
+        file_key: himawari_8_ahi_channel_1_reflectance
+        standard_name: toa_bidirectional_reflectance
+        units: "%"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B02:
+    name: B02
+    sensor: ahi
+    wavelength: [0.49,0.51,0.53]
+    calibration:
+      reflectance:
+        file_key: himawari_8_ahi_channel_2_reflectance
+        standard_name: toa_bidirectional_reflectance
+        units: "%"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B03:
+    name: B03
+    sensor: ahi
+    wavelength: [0.62,0.64,0.66]
+    calibration:
+      reflectance:
+        file_key: himawari_8_ahi_channel_3_reflectance
+        standard_name: toa_bidirectional_reflectance
+        units: "%"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B04:
+    name: B04
+    sensor: ahi
+    wavelength: [0.83, 0.85, 0.87]
+    calibration:
+      reflectance:
+        file_key: himawari_8_ahi_channel_4_reflectance
+        standard_name: toa_bidirectional_reflectance
+        units: "%"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B05:
+    name: B05
+    sensor: ahi
+    wavelength: [1.5, 1.6, 1.7]
+    calibration:
+      reflectance:
+        file_key: himawari_8_ahi_channel_5_reflectance
+        standard_name: toa_bidirectional_reflectance
+        units: "%"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B06:
+    name: B06
+    sensor: ahi
+    wavelength: [2.2, 2.3, 2.4]
+    calibration:
+      reflectance:
+        file_key: himawari_8_ahi_channel_6_reflectance
+        standard_name: toa_bidirectional_reflectance
+        units: "%"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B07:
+    name: B07
+    sensor: ahi
+    wavelength: [3.7, 3.9, 4.1]
+    calibration:
+      brightness_temperature:
+        file_key: himawari_8_ahi_channel_7_brightness_temperature
+        standard_name: toa_brightness_temperature
+        units: "K"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B08:
+    name: B08
+    sensor: ahi
+    wavelength: [6.0, 6.2, 6.4]
+    calibration:
+      brightness_temperature:
+        file_key: himawari_8_ahi_channel_8_brightness_temperature
+        standard_name: toa_brightness_temperature
+        units: "K"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B09:
+    name: B09
+    sensor: ahi
+    wavelength: [6.7, 6.9, 7.1]
+    calibration:
+      brightness_temperature:
+        file_key: himawari_8_ahi_channel_9_brightness_temperature
+        standard_name: toa_brightness_temperature
+        units: "K"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B10:
+    name: B10
+    sensor: ahi
+    wavelength: [7.1, 7.3, 7.5]
+    calibration:
+      brightness_temperature:
+        file_key: himawari_8_ahi_channel_10_brightness_temperature
+        standard_name: toa_brightness_temperature
+        units: "K"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B11:
+    name: B11
+    sensor: ahi
+    wavelength: [8.4, 8.6, 8.8]
+    calibration:
+      brightness_temperature:
+        file_key: himawari_8_ahi_channel_11_brightness_temperature
+        standard_name: toa_brightness_temperature
+        units: "K"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B12:
+    name: B12
+    sensor: ahi
+    wavelength: [9.4, 9.6, 9.8]
+    calibration:
+      brightness_temperature:
+        file_key: himawari_8_ahi_channel_12_brightness_temperature
+        standard_name: toa_brightness_temperature
+        units: "K"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B13:
+    name: B13
+    sensor: ahi
+    wavelength: [10.2, 10.4, 10.6]
+    calibration:
+      brightness_temperature:
+        file_key: himawari_8_ahi_channel_13_brightness_temperature
+        standard_name: toa_brightness_temperature
+        units: "K"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B14:
+    name: B14
+    sensor: ahi
+    wavelength: [11.0, 11.2, 11.4]
+    calibration:
+      brightness_temperature:
+        file_key: himawari_8_ahi_channel_14_brightness_temperature
+        standard_name: toa_brightness_temperature
+        units: "K"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B15:
+    name: B15
+    sensor: ahi
+    wavelength: [12.2, 12.4, 12.6]
+    calibration:
+      brightness_temperature:
+        file_key: himawari_8_ahi_channel_15_brightness_temperature
+        standard_name: toa_brightness_temperature
+        units: "K"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
+  B16:
+    name: B16
+    sensor: ahi
+    wavelength: [13.1, 13.3, 13.5]
+    calibration:
+      brightness_temperature:
+        file_key: himawari_8_ahi_channel_16_brightness_temperature
+        standard_name: toa_brightness_temperature
+        units: "K"
+#      radiance:
+#        standard_name: toa_outgoing_radiance_per_unit_wavelength
+#        units: W m-2 um-1 sr-1
+    file_type: ahi_level1
\ No newline at end of file
diff --git a/satpy/readers/file_handlers.py b/satpy/readers/file_handlers.py
index 9143463753..26fcf75b8b 100644
--- a/satpy/readers/file_handlers.py
+++ b/satpy/readers/file_handlers.py
@@ -114,3 +114,8 @@ def start_time(self):
     @property
     def end_time(self):
         return self.filename_info.get('end_time', self.start_time)
+
+    @property
+    def sensor_names(self):
+        """List of sensors represented in this file."""
+        raise NotImplementedError
diff --git a/satpy/readers/geocat.py b/satpy/readers/geocat.py
index 3dcc06c7a6..9472c5f03f 100644
--- a/satpy/readers/geocat.py
+++ b/satpy/readers/geocat.py
@@ -74,6 +74,7 @@ class GEOCATFileHandler(NetCDF4FileHandler):
         'ahi': {
             1: 999.9999820317674,  # assumption
             2: 1999.999964063535,
+            4: 3999.99992812707,
         }
     }
 
@@ -101,6 +102,10 @@ def _get_proj(self, platform, ref_lon):
             ref_lon = -75.
         return GEO_PROJS[platform].format(lon_0=ref_lon)
 
+    @property
+    def sensor_names(self):
+        return [self.get_sensor(self['/attr/Sensor_Name'])]
+
     @property
     def start_time(self):
         return self.filename_info['start_time']
@@ -114,11 +119,20 @@ def is_geo(self):
         platform = self.get_platform(self['/attr/Platform_Name'])
         return platform in GEO_PROJS
 
-    def available_dataset_ids(self):
-        """Automatically determine datasets provided by this file"""
+    @property
+    def resolution(self):
         elem_res = self['/attr/Element_Resolution']
+        return int(elem_res * 1000)
+
+    def _calc_area_resolution(self, ds_res):
+        elem_res = round(ds_res / 1000.)  # mimic 'Element_Resolution' attribute from above
         sensor = self.get_sensor(self['/attr/Sensor_Name'])
-        res = self.resolutions.get(sensor, {}).get(int(elem_res), elem_res * 1000.)
+        return self.resolutions.get(sensor, {}).get(int(elem_res),
+                                                    elem_res * 1000.)
+
+    def available_dataset_ids(self):
+        """Automatically determine datasets provided by this file"""
+        res = self.resolution
         coordinates = ['pixel_longitude', 'pixel_latitude']
         for var_name, val in self.file_content.items():
             if isinstance(val, netCDF4.Variable):
@@ -174,7 +188,7 @@ def get_area_def(self, dsid):
             raise NotImplementedError("Don't know how to get the Area Definition for this file")
 
         platform = self.get_platform(self['/attr/Platform_Name'])
-        res = dsid.resolution
+        res = self._calc_area_resolution(dsid.resolution)
         proj = self._get_proj(platform, float(self['/attr/Subsatellite_Longitude']))
         area_name = '{} {} Area at {}m'.format(
             platform,
@@ -232,6 +246,7 @@ def get_dataset(self, dataset_id, ds_info, xslice=slice(None), yslice=slice(None
             data = data * factor + offset
 
         data.attrs.update(info)
+        data = data.rename({'lines': 'y', 'elements': 'x'})
         return data
 
 
@@ -243,8 +258,22 @@ def create_filehandlers(self, filenames):
     def load_ds_ids_from_files(self):
         for file_handlers in self.file_handlers.values():
             fh = file_handlers[0]
+            # update resolution in the dataset IDs for this files resolution
+            res = fh.resolution
+            for ds_id, ds_info in list(self.ids.items()):
+                if fh.filetype_info['file_type'] != ds_info['file_type']:
+                    continue
+                if ds_id.resolution is not None:
+                    continue
+                ds_info['resolution'] = res
+                new_id = DatasetID.from_dict(ds_info)
+                self.ids[new_id] = ds_info
+                del self.ids[ds_id]
+
+            # dynamically discover other available datasets
             for ds_id, ds_info in fh.available_dataset_ids():
                 # don't overwrite an existing dataset
                 # especially from the yaml config
                 self.ids.setdefault(ds_id, ds_info)
 
+
diff --git a/satpy/readers/yaml_reader.py b/satpy/readers/yaml_reader.py
index d191a5dbbe..b9a50cf3e3 100644
--- a/satpy/readers/yaml_reader.py
+++ b/satpy/readers/yaml_reader.py
@@ -104,12 +104,15 @@ def __init__(self, config_files):
 
         if not isinstance(self.info['sensors'], (list, tuple)):
             self.info['sensors'] = [self.info['sensors']]
-        self.sensor_names = self.info['sensors']
         self.datasets = self.config.get('datasets', {})
         self.info['filenames'] = []
         self.ids = {}
         self.load_ds_ids_from_config()
 
+    @property
+    def sensor_names(self):
+        return self.info['sensors']
+
     @property
     def all_dataset_ids(self):
         return self.ids.keys()
@@ -396,6 +399,23 @@ def __init__(self,
             logger.warning("Unrecognized/unused reader keyword argument(s) '{}'".format(kwargs))
         self.coords_cache = WeakValueDictionary()
 
+    @property
+    def sensor_names(self):
+        if not self.file_handlers:
+            return self.info['sensors']
+
+        file_handlers = (handlers[0] for handlers in
+                         self.file_handlers.values())
+        sensor_names = set()
+        for fh in file_handlers:
+            try:
+                sensor_names.update(fh.sensor_names)
+            except NotImplementedError:
+                continue
+        if not sensor_names:
+            return self.info['sensors']
+        return sorted(sensor_names)
+
     @property
     def available_dataset_ids(self):
         for ds_id in self.all_dataset_ids:
diff --git a/satpy/resample.py b/satpy/resample.py
index 5af73428ad..7a6ccd7db9 100644
--- a/satpy/resample.py
+++ b/satpy/resample.py
@@ -577,8 +577,8 @@ def compute(self, data, expand=True, **kwargs):
 
         out_shape = target_geo_def.shape
         in_shape = data.shape
-        y_repeats = out_shape[y_axis] / float(in_shape[y_axis])
-        x_repeats = out_shape[x_axis] / float(in_shape[x_axis])
+        y_repeats = out_shape[0] / float(in_shape[y_axis])
+        x_repeats = out_shape[1] / float(in_shape[x_axis])
         repeats = {
             y_axis: y_repeats,
             x_axis: x_repeats,
@@ -597,6 +597,9 @@ def compute(self, data, expand=True, **kwargs):
                 coords['y'] = y_coord
             if 'x' in data.coords:
                 coords['x'] = x_coord
+        for dim in data.dims:
+            if dim not in ['y', 'x'] and dim in data.coords:
+                coords[dim] = data.coords[dim]
 
         return xr.DataArray(d_arr,
                             dims=data.dims,
diff --git a/satpy/tests/compositor_tests/__init__.py b/satpy/tests/compositor_tests/__init__.py
index b3a169a5c4..1e6b6fce80 100644
--- a/satpy/tests/compositor_tests/__init__.py
+++ b/satpy/tests/compositor_tests/__init__.py
@@ -22,7 +22,7 @@
 
 import sys
 
-from satpy.tests.compositor_tests import test_abi
+from satpy.tests.compositor_tests import test_abi, test_ahi
 
 if sys.version_info < (2, 7):
     import unittest2 as unittest
@@ -119,6 +119,7 @@ def suite():
     loader = unittest.TestLoader()
     mysuite = unittest.TestSuite()
     mysuite.addTests(test_abi.suite())
+    mysuite.addTests(test_ahi.suite())
     mysuite.addTest(loader.loadTestsFromTestCase(TestCheckArea))
 
     return mysuite
diff --git a/satpy/tests/compositor_tests/test_abi.py b/satpy/tests/compositor_tests/test_abi.py
index 38ce051a8a..f3aae8c782 100644
--- a/satpy/tests/compositor_tests/test_abi.py
+++ b/satpy/tests/compositor_tests/test_abi.py
@@ -28,7 +28,11 @@
 
 
 class TestABIComposites(unittest.TestCase):
+
+    """Test ABI-specific composites."""
+
     def test_simulated_green(self):
+        """Test creating a fake 'green' band."""
         import xarray as xr
         import dask.array as da
         import numpy as np
@@ -65,7 +69,7 @@ def test_simulated_green(self):
 
 
 def suite():
-    """The test suite for test_scene.
+    """The test suite for test_abi.
     """
     loader = unittest.TestLoader()
     mysuite = unittest.TestSuite()
diff --git a/satpy/tests/compositor_tests/test_ahi.py b/satpy/tests/compositor_tests/test_ahi.py
new file mode 100644
index 0000000000..93d300fa0e
--- /dev/null
+++ b/satpy/tests/compositor_tests/test_ahi.py
@@ -0,0 +1,74 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2018 PyTroll developers
+#
+#
+# This program 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.
+#
+# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+"""Tests for AHI compositors.
+"""
+
+import sys
+
+if sys.version_info < (2, 7):
+    import unittest2 as unittest
+else:
+    import unittest
+
+
+class TestAHIComposites(unittest.TestCase):
+
+    """Test AHI-specific composites."""
+
+    def test_corrected_green(self):
+        """Test adjusting the 'green' band."""
+        import xarray as xr
+        import dask.array as da
+        import numpy as np
+        from satpy.composites.ahi import GreenCorrector
+        from pyresample.geometry import AreaDefinition
+        rows = 5
+        cols = 10
+        area = AreaDefinition(
+            'test', 'test', 'test',
+            {'proj': 'eqc', 'lon_0': 0.0,
+             'lat_0': 0.0},
+            cols, rows,
+            (-20037508.34, -10018754.17, 20037508.34, 10018754.17))
+
+        comp = GreenCorrector('green', prerequisites=(0.51, 0.85),
+                              standard_name='toa_bidirectional_reflectance')
+        c01 = xr.DataArray(da.zeros((rows, cols), chunks=25) + 0.25,
+                           dims=('y', 'x'),
+                           attrs={'name': 'C01', 'area': area})
+        c02 = xr.DataArray(da.zeros((rows, cols), chunks=25) + 0.30,
+                           dims=('y', 'x'),
+                           attrs={'name': 'C02', 'area': area})
+        res = comp((c01, c02))
+        self.assertIsInstance(res, xr.DataArray)
+        self.assertIsInstance(res.data, da.Array)
+        self.assertEqual(res.attrs['name'], 'green')
+        self.assertEqual(res.attrs['standard_name'],
+                         'toa_bidirectional_reflectance')
+        data = res.compute()
+        np.testing.assert_allclose(data, 0.2575)
+
+
+def suite():
+    """The test suite for test_ahi.
+    """
+    loader = unittest.TestLoader()
+    mysuite = unittest.TestSuite()
+    mysuite.addTest(loader.loadTestsFromTestCase(TestAHIComposites))
+    return mysuite
diff --git a/satpy/tests/reader_tests/test_geocat.py b/satpy/tests/reader_tests/test_geocat.py
index 2853bcf391..9c48cb7341 100644
--- a/satpy/tests/reader_tests/test_geocat.py
+++ b/satpy/tests/reader_tests/test_geocat.py
@@ -96,7 +96,7 @@ def get_test_content(self, filename, filename_info, filetype_info):
                     if key + '/attr/' + a in file_content:
                         attrs[a] = file_content[key + '/attr/' + a]
                 if val.ndim > 1:
-                    file_content[key] = DataArray(val, dims=('y', 'x'), attrs=attrs)
+                    file_content[key] = DataArray(val, dims=('lines', 'elements'), attrs=attrs)
                 else:
                     file_content[key] = DataArray(val, attrs=attrs)