fix return of field_of_view

goes2go/accessors.py

@@ -213,7 +213,6 @@ def full_disk(self):
             FOV_degrees -= 0.06
             FOV_radius = np.radians(FOV_degrees / 2) * sat_height
             FOV_polygon = Point(0, 0).buffer(FOV_radius, resolution=160)
-            return FOV_polygon
         elif ds.title.startswith("GLM"):
             # Field of view (FOV) of GLM is different than ABI.
             # Do a little offset to better match boundary from
@@ -240,7 +239,7 @@ def full_disk(self):
             )
             cutout = Polygon(cutout_points)
             FOV_polygon = FOV_polygon.intersection(cutout)
-            return FOV_polygon
+        return FOV_polygon
 
     @property
     def domain(self):

goes2go/rgb.py

@@ -8,12 +8,12 @@
 
 .. image:: /_static/RGB_sample.png
 
-These functions take GOES-East or GOES-West multichannel data on a 
-fixed grid (files named ``ABI-L2-MCMIPC``) and generates a 3D 
+These functions take GOES-East or GOES-West multichannel data on a
+fixed grid (files named ``ABI-L2-MCMIPC``) and generates a 3D
 Red-Green-Blue (RGB) array for various GOES RGB products.
 
 RGB recipes are based on the `GOES Quick Guides
-<http://rammb.cira.colostate.edu/training/visit/quick_guides/>`_ 
+<http://rammb.cira.colostate.edu/training/visit/quick_guides/>`_
 and include the following:
 
     - NaturalColor
@@ -36,38 +36,38 @@
     - NightFogDifference
     - RocketPlume              ✨New - July 9, 2021
 
-The returned RGB can easily be viewed with ``plt.imshow(RGB)``. 
+The returned RGB can easily be viewed with ``plt.imshow(RGB)``.
 
-For imshow to show an RGB image, the values must range between 0 and 1. 
-Values are normalized between the range specified in the Quick Guides. 
-This normalization is synonymous to `contrast or histogram stretching 
+For imshow to show an RGB image, the values must range between 0 and 1.
+Values are normalized between the range specified in the Quick Guides.
+This normalization is synonymous to `contrast or histogram stretching
 <https://micro.magnet.fsu.edu/primer/java/digitalimaging/processing/histogramstretching/index.html>`_
 (`more info here
 <https://staff.fnwi.uva.nl/r.vandenboomgaard/IPCV20162017/LectureNotes/IP/PointOperators/ImageStretching.html>`_)
 and follows the formula:
 
-    .. code-block:: python 
+    .. code-block:: python
 
         NormalizedValue = (OriginalValue-LowerLimit)/(UpperLimit-LowerLimit)
 
 `Gamma correction <https://en.wikipedia.org/wiki/Gamma_correction>`_
-darkens or lightens an image (`more info 
-<https://www.cambridgeincolour.com/tutorials/gamma-correction.htm>`_) 
+darkens or lightens an image (`more info
+<https://www.cambridgeincolour.com/tutorials/gamma-correction.htm>`_)
 and follows the decoding formula:
 
-    .. code-block:: python 
-        
+    .. code-block:: python
+
         R_corrected = R**(1/gamma)
 
 The input for all these functions are denoted by ``C`` for "channels" which
 represents the GOES ABI multichannel file opened with xarray. For example:
 
-    .. code-block:: python 
-        
+    .. code-block:: python
+
         FILE = 'OR_ABI-L2-MCMIPC-M6_G17_s20192201631196_e20192201633575_c20192201634109.nc'
         C = xarray.open_dataset(FILE)
 
-All RGB products are demonstarted in the `make_RGB_Demo 
+All RGB products are demonstarted in the `make_RGB_Demo
 <https://github.com/blaylockbk/goes2go/tree/master/notebooks>`_ notebook.
 
 Note: I don't have a `GeoColor <https://journals.ametsoc.org/view/journals/atot/37/3/JTECH-D-19-0134.1.xml>`_
@@ -164,7 +164,7 @@ def rgb_as_dataset(G, RGB, description, latlon=False):
     ds.attrs["description"] = description
 
     # Convert x, y points to latitude/longitude
-    _, crs = field_of_view(G)
+    _, _, crs = field_of_view(G)
     sat_h = G.goes_imager_projection.perspective_point_height
     x2 = G.x * sat_h
     y2 = G.y * sat_h

goes2go/tools.py

@@ -34,9 +34,9 @@ def field_of_view(G, resolution=60, reduce_abi_fov=0.06):
 
     .. code:: python
 
-        FOV, geo = field_of_view(G)
-        ax = plt.subplot(projection=geo)
-        ax.add_geometries([FOV], crs=geo)
+        pFOV_inst, pFOV_dom, crs = field_of_view(G)
+        ax = plt.subplot(projection=crs)
+        ax.add_geometries([FOV], crs=crs)
 
     Parameters
     ----------
@@ -51,6 +51,12 @@ def field_of_view(G, resolution=60, reduce_abi_fov=0.06):
         plane. If this number is less than the default, the polygon
         will not be calculated correctly because edge points will lie
         off the projection globe.
+
+    Returns
+    -------
+    pFOV_inst is a polygon of the instrument field of view.
+    pFOV_dom is a polygon of the domain field of view
+    crs is the cartopy coordinate reference system for the instrument
     """
     warnings.warn(
         "DEPRECIATION. Use the FOV accessor instead `G.FOV.full_disk` or `G.FOV.domain`"
@@ -97,7 +103,7 @@ def field_of_view(G, resolution=60, reduce_abi_fov=0.06):
     # we are working in the geostationary projection coordinates
     # and the center point is 0,0 meters.
     FOV_radius = np.radians(FOV / 2) * sat_height
-    FOV_poly = Point(0, 0).buffer(FOV_radius, resolution=resolution)
+    pFOV_inst = Point(0, 0).buffer(FOV_radius, resolution=resolution)
 
     ## GLM is a bit funny. I haven't found this in the documentation
     ## anywhere, yet, but the GLM field-of-view is not exactly
@@ -127,22 +133,22 @@ def field_of_view(G, resolution=60, reduce_abi_fov=0.06):
         x = np.hstack([side1x, side2x, side3x, side4x])
         y = np.hstack([side1y, side2y, side3y, side4y])
         square_FOV = Polygon(zip(x, y))
-        FOV_poly = FOV_poly.intersection(square_FOV)
-
-        return FOV_poly, crs
+        pFOV_inst = pFOV_inst.intersection(square_FOV)
+        pFOV_dom = None # there is no "domain" for the GLM instrument
 
     if G.title.startswith("ABI"):
-        # We have the global field of view
+        # We have the global field of view,
         # now we need the domain field of view
         dom_border = np.array(
             [(i, G.y.data[0]) for i in G.x.data]
             + [(G.x.data[-1], i) for i in G.y.data]
             + [(i, G.y.data[-1]) for i in G.x.data[::-1]]
             + [(G.x.data[0], i) for i in G.y.data[::-1]]
         )
-        FOV_dom = Polygon(dom_border * sat_height)
-        FOV_dom = FOV_dom.intersection(FOV_poly)
-        return FOV_poly, FOV_dom, crs
+        pFOV_dom = Polygon(dom_border * sat_height)
+        pFOV_dom = pFOV_dom.intersection(pFOV_inst)
+
+    return pFOV_inst, pFOV_dom, crs
 
 
 def abi_crs(G, reference_variable="CMI_C01"):