Visibility Contours of the Sun and Moon

Create graphic visibility contours of the Sun and Moon at a user-specified calendar date and time.

This MATLAB script, vcontour, can be used to display a visibility contour of the Sun or Moon at a user specified calendar date and time. The contour is displayed on a Mercator map of the world along with the sub-point of the celestial body.

User interaction with the script

The following is a typical user interaction with the vcontour script. The software requires a calendar date and UTC time along with the celestial body of interest. The relationship between Coordinated Universal Time, UTC, and local civil time, LCT, is given by UTC = LCT - DST + ZONE where LCTis the local civil time in 24 hour format, DST is the Daylight Savings Time status (0 = no, 1 = yes) and ZONE is the user’s time zone.

vcontour visibility contour of the sun and moon

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please input the calendar date

(1 <= month <= 12, 1 <= day <= 31, year = all digits!)

? 7,22,2025

please input the utc time

(0 <= hours <= 24, 0 <= minutes <= 60, 0 <= seconds <= 60)

? 9,0,0

celestial body selection

1 = sun

2 = moon

? 1