Instructions: This calculator may be used to calculate the polar axis alignment error after performing a drift alignment if the declination drift can be ascertained with reasonable precision. For more information on the mathematical model behind this calculator see my article on the subject. Drift: Enter the total arcseconds of drift. If the drift is south enter a negative number. Time: Enter the total time of the measurement in decimal minutes. If you know the seconds enter that number and click "Convert Secconds" If you know the minutes and seconds enter it as MM.SS and click "Convert MM.SS". Declination: Enter the declination of the drift star in decimal degrees. If you know the degrees, arcminutes, and arcseconds enter it in the form DDD.MMSS or DD.MM and click "Convert DDD.MMSS". azimuth/altitude: Select the azimuth button if you measured drift east or west, altitude if measured on the equator/meridian. east/west: If this was an altitude drift, select if you were measuring drift in the east or west. Southern Hemisphere: Check this box if your latitude is negative. Calculate: When you have entered and converted all your inputs to the proper units, click "Calculate." The Drift Rate and Alignment Error will be calculated and displayed in the fields below.