Astronavigation: Latitude and Longitude from two stars

Measure altitudes of two stars and corresponding Greenwich Mean Time
Calculate Latitude and Longitude of measurement Location

Star 1

Altitude of Star
Deg  Min   Sec

Right Ascention of Star
Hour Min Sec

Declination of Star
Deg  Min   Sec

Greenwich Mean Time
Year  Month   Day
Hour  Min   Sec

       Star 2

Altitude of Star
Deg  Min   Sec

Right Ascention of Star
Hour Min Sec

Declination of Star
Deg  Min   Sec

Greenwich Mean Time
Year  Month   Day
Hour  Min   Sec

GIVE Initial Latitude and Longitude (reckoning, assumed location)
Latitude:    Deg min sec
Longitude: Deg min sec

Click on Button:


The Position of the measurement location is:
Latitude:    degrees minutes seconds
Longitude: degrees minutes seconds
Quality:

Additional Information:
Star1: Julian Day at UT0:   Julian Date at UT:
Star1: Greenwich Mean Sidereal Time (GMST): hour min sec
Star1: Local Sidereal Time (LST): hours min sec
Local Hour Angle (LHA) of hours min sec = deg min sec
Greenwich Hour Angle (GHA) of hours min sec = deg min sec
Sidereal Hour Angle (SHA) of hours min sec = deg min sec


Mathematical Backround of Two Star's Method

Calculate Altitude and Azimuth of a Star

Calculate position from one star's azimuth and altitude
Not so good, but suitable for emergency situations when only one star is visible

Navigation, Astronavigation, Positioning, Geodesy

Juhani Kaukoranta, Raahen lukio, Finland
 Email: juhani.kaukoranta@mail.suomi.net
Homepage: http://koti.mbnet.fi/jukaukor/
Last changes 2.6.2006