Astronavigation: Latitude and Longitude from one Star

Measure Azimuth and Altitude of a Star and UT (Greenwich Mean Time)
Calculate Latitude and Longitude of measurement Location.
This is not as good as two star's altitude, but sometimes you see only one star...


Right Ascention of Star
Hour Min Sec

Declination of Star
Deg  Min   Sec

Greenwich Mean Time (UT)
Year  Month   Day
Hour  Min   Sec

Altitude of Star
Deg  Min   Sec

North Azimuth of Star
Deg  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


Additional Information:
Julian Day at UT0:
Greenwich Mean Sidereal Time (GMST): hour min sec
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 Background of One Star Altitude and Azimuth Method

Navigation, Astronavigation, Positioning, Geodesy

Juhani Kaukoranta, Raahen lukio, Finland
Last changes 15.10.2022