and twilight solar elevation constants

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/info/blueshift.texinfo b/info/blueshift.texinfo
index 1b9a344..b61d28e 100644
--- a/info/blueshift.texinfo
+++ b/info/blueshift.texinfo
@@ -900,6 +900,43 @@ time in Julian Centuries. All parameters are floating point
 and may not be @code{None}, except for in @code{solar_elevation},
 as specified.
 
+Blueshift provides constants with important elevations of
+the Sun during twilight.
+
+@table @code
+@item SOLAR_ELEVATION_SUNSET_SUNRISE
+The Sun's elevation at sunset and sunrise,
+measured in degrees.
+
+@item SOLAR_ELEVATION_CIVIL_DUSK_DAWN
+The Sun's elevation at civil dusk and civil dawn,
+measured in degrees.
+
+@item SOLAR_ELEVATION_NAUTICAL_DUSK_DAWN
+The Sun's elevation at nautical dusk and nautical
+dawn, measured in degrees.
+
+@item SOLAR_ELEVATION_ASTRONOMICAL_DUSK_DAWN
+The Sun's elevation at astronomical dusk and
+astronomical dawn, measured in degrees.
+
+@item SOLAR_ELEVATION_RANGE_TWILIGHT
+The Sun's lowest and highest elevation during all
+periods of twilight, measured in degrees.
+
+@item SOLAR_ELEVATION_RANGE_CIVIL_TWILIGHT
+The Sun's lowest and highest elevation during
+civil twilight, measured in degrees.
+
+@item SOLAR_ELEVATION_RANGE_NAUTICAL_TWILIGHT
+The Sun's lowest and highest elevation during
+nautical twilight, measured in degrees.
+
+@item SOLAR_ELEVATION_RANGE_ASTRONOMICAL_TWILIGHT
+The Sun's lowest and highest elevation during
+astronomical twilight, measured in degrees.
+@end table
+
 
 
 @node Terminology