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+.TH LIBRED_SOLAR_ELEVATION 3 LIBRED
+.SH NAME
+libred_solar_elevation \- Calculate the Sun's apparent elevation
+.SH SYNOPSIS
+.nf
+#include <libred.h>
+
+double \fBlibred_solar_elevation\fP(double \fIlatitude\fP, double \fIlongitude\fP);
+.fi
+.PP
+Link with
+.IR -lred .
+.SH DESCRIPTION
+.B libred_solar_elevation
+calculates the Sun's  elevation as apparent from a select geographical position.
+Namely from
+.I latitude
+degrees north of GPS's equator and
+.I longitude
+degrees east of GPS's prime meridian. The function is only explicitly defined for
+values between -90 and +90 for
+.I latitude
+and values between -180 and +180 for and
+.IR longitude .
+Other values may or may not work, no error is thrown if used.
+.SH "RETURN VALUE"
+Upon successful completion, the function sets
+.B errno
+to 0 and returns the Sun's current apparent elevation, measured in
+degrees above the horizon. On failure, the function returns an
+arbitrary value (happens to always be 0.0) and sets
+.B errno
+an a non-zero value.
+.SH ERRORS
+The function may fail for any reason specified for
+.BR clock_gettime (3),
+and set the value of
+.B errno
+to the same values.
+.B errno
+is always set to 0 on success.
+.SH "FUTURE DIRECTIONS"
+None.
+.SH "SEE ALSO"
+.BR libred.h (0),
+.BR libred (7),
+.BR libred_check_timetravel (3),
+.BR libred_init_colour (3)