How to use STELLA PROGRAM

1 Input Initial Fix

Task → New Initial Fix → input data ( Day, Month, Year, Hour, Min, Sec, Position, Course, Speed ) → OK

* Time to input(UTC) = GMT (Greenwich mean time) = (Zulu time)

2 Predict the time of Morning Nautical ( Civil ) Twilight

Task → Rise/Set/Transit → Underway → input data ( Time Zone, Height of eye, Body(Sun)) → OK → look at : Beg Naut Twi ( Beg Civ Twi ):

3 Plan your observation; Select the best stars to observe at a given time

Task → Sight Planning → Selected stars → click : Other : → input observed time ( Z time ) → OK → the symbol “< >” means first priority stars → determine Zn and Hc

4 Record your observation data and take celestial fix

Task → Sight Reduction → Record Observation → input data ( observed time (GMT ), Body, hs, Height of eye, IC, Temperature, Pressure ) → Add → Repeat the procedure for other stars → Done → Save to log

Task → Sight Reduction → Compute Fix → click : Time of Last Observation : → OK → Enter → look at celestial fix → click : Exit : → Save to log →

5 LAN

Task → Rise/Set/Transit → Underway → input data ( Time Zone, Height of eye, Body(Sun)) → OK → look at : Transit ( LAN )

6 Determine Lat by LAN

Task → Sight Reduction → Record Observation → input data ( observed time ( GMT ), Body (Sun ), hs, Limb ( LL means Lower Limb ), Height of eye, IC, Temperature, Pressure ) → Add → Done → Save to log

Task → Sight Reduction → Compute Fix → Enter → look at the latitude of celestial fix → click : Exit : → Save to log

7 Input New Position ( Update your position )

Task → Position Update → External Fix → input data ( Hour, Min, Sec, Position, Course, Speed ) → OK → Save to log(Don`t forget it)

* Time to input = GMT

8 Predict the time of Evening Nautical (Civil) Twilight

Task → Rise/Set/Transit → Underway → input data ( Time Zone, Height of eye, Body(Sun)) → OK → look at : End Naut Twi ( End Civ Twi ):

9 Determine lat by Polaris

Task → Sight Reduction → Record Observation → input data ( observed time ( GMT ), Body (Polaris), hs, Height of eye, IC, Temperature, Pressure ) → Add → Done → Save to log

Task → Sight Reduction → Compute Fix → Enter → look at celestial fix latitude → click : Exit : → Save to log

10 Gyro Error (Polaris)

Task → Gyro/Compass Error → Determination → input data: Time GMT, Azimuth (Gyro Brg to Polaris), Body (Polaris)) → OK → Save to log → look at : Exact Azimuth ( = True Azimuth ) and Gyro/Compass Error