NavList:

You can also place a mark representing the location of Polaris on an E-6B, a Mk 6a plotting board or on a Pohemus computer to calculate the correction for Polaris. Place the dot on the rotating disk in such a position so you can set it to LHA Aries instead of LHA Polaris, saves a little bit of work,


http://www.fer3.com/arc/m2.aspx?i=108473&y=200905

http://www.fer3.com/arc/m2.aspx?i=109875&y=200909

http://www.fer3.com/arc/m2.aspx?i=105846

After plotting the position of Polaris merely turn the disk to the LHA Aries and read the correction from the vertical scale. This is not a new idea it is only a modern "nocturnal."

You can also add a scale on the HO 2102-D to accomplish the same thing.

http://www.fer3.com/arc/imgx/IMG_0148.JPG

the purple scale along the edge.Set in LHA Aries and read out the correction.

http://www.fer3.com/arc/m2.aspx?i=107982&y=200904

You need to replot Polaris every year or so or you can use the epoch 2010 position from H.O. 249 for a long period as long as you apply the "precession and nutation" correction to the Polaris LOP. Of course you can just use the "Q" correction table from the Air Almanac or from H.O. 249 remembering the "P&N" correction if using the H.O. 249 "Q" table."

gl

gl










Greg Rudzinski wrote:

A radar plotting sheet can be used for correcting a Polaris HO to get Latitude. 90° minus Polaris declination will give the diameter of the circle in minutes of arc. The attached example is 90° - 89° 18.4' for a 41.6' plotting sheet circle diameter. Intersect the circle with the LHA of Polaris then measure to the baseline with dividers. The scale at the upper left will provide the correction to better than a minute of arc.


      
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