Better mimic NCL's satellite projection (#609)

* Update NCL_sat_1.py to use a satellite projection equivalent * Better mimic NCL's satellite projection * formatting
NCAR · Jul 8, 2024 · 9fe8b5a · 9fe8b5a
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commit 9fe8b5a
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Showing 3 changed files with 14 additions and 8 deletions.
diff --git a/Gallery/MapProjections/NCL_sat_1.py b/Gallery/MapProjections/NCL_sat_1.py
@@ -48,8 +48,11 @@
 # Set figure size
 fig = plt.figure(figsize=(8, 8))
 
-# Set global axes with an orthographic projection
-proj = ccrs.Orthographic(central_longitude=270, central_latitude=45)
+# Set global axes with a nearside perspective projection (equivalent to NCL's
+# satellite projection)
+proj = ccrs.NearsidePerspective(central_longitude=270.0,
+                                central_latitude=45.0,
+                                satellite_height=12742000)
 ax = plt.axes(projection=proj)
 ax.set_global()
 

diff --git a/Gallery/MapProjections/NCL_sat_2.py b/Gallery/MapProjections/NCL_sat_2.py
@@ -50,8 +50,11 @@
 # Set figure size
 fig = plt.figure(figsize=(8, 8))
 
-# Set global axes with an orthographic projection
-proj = ccrs.Orthographic(central_longitude=270, central_latitude=45)
+# Set global axes with a nearside perspective projection (equivalent to NCL's
+# satellite projection)
+proj = ccrs.NearsidePerspective(central_longitude=270.0,
+                                central_latitude=45.0,
+                                satellite_height=12742000)
 ax = plt.axes(projection=proj)
 ax.set_global()
 

diff --git a/Gallery/MapProjections/NCL_sat_3.py b/Gallery/MapProjections/NCL_sat_3.py
@@ -41,10 +41,10 @@
 
 plt.figure(figsize=(8, 8))
 
-# Create an axis with an orthographic projection
-ax = plt.axes(projection=ccrs.Orthographic(central_longitude=-35,
-                                           central_latitude=60),
-              anchor='C')
+# Create an axis with an orthographic projection (equivalent to NCL's satellite
+# projection where mpSatelliteDistF <= 1.0)
+ax = plt.axes(
+    projection=ccrs.Orthographic(central_longitude=-35, central_latitude=60))
 
 # Set extent of map
 ax.set_extent((-80, -10, 30, 80), crs=ccrs.PlateCarree())