
GeoAstro Applets 
Astronomy 
Chaos Game 
Java 
Miscel laneous 
Physics Quiz 
Who is Who ? 
To
change the input of the "Home Latitude" text field click into the applet area within the red frame first. 


Enter your latitude in decimal
degrees, 
Select from
the "Details" menu. 
The pattern of the
Sun Compass disk consists of ellipses, each
corresponding to a particular latitude, crossed by
hyperbola, corresponding to the local apparent time
hours. The gnomon has to be placed on the current day of the date scale (divided by intervals of 7 days) taking into account the change of the Sun's declination. To use the compass, the shadow must be kept on the local apparent time of day along the correct ellipse for the latitude of the place. The 12 hours line is pointing True North then. 
The hours on the
disk above are Local
Apparent Time (LAT), which is computed from
Standard Time (ST) taking into account the longitude of
own position, the longitude of the Standard Time, and the
equation of time (EQT), . The correction (D) is +4 minutes per degree of longitude East of Standard Time, or 4 minutes per degree of longitude West of Standard Time, plus the equation of time (EQT): LAT = ST + D
+ EQT
Example:
For a location at 10° E the longitude of Standard Time is 15° E, thus D=5*(4min)=20min. For EQT=12min, Standard Time 15:00, the Local Apparent Time is: LAT = 15:00
 00:20  00:12 = 14:28
