Celestial One Sunline Plot

If you are entering this Link, following along from Celestial One, the description is pretty close to the accuracy of the plot.

First note that our plotting sheet is set up to accommodate our assumed position of Lat: 28 N, Lon: 62-36 W. (The preceeding Link in Diagrams will show the mechanics in setting up the sheet.)

My assumed position is appropriately marked on the chart (AP). Now I draw my Azimuth Z… The dashed directional line 125 degrees, taken of course off the center of the compass rose. An arrow head indicates the direction toward the GP of the Sun.

Now I turn my attention to our final answer which is called our Intercept. The difference between our adjusted sextant angle, taken from the bridge termed HO and our calculation which tells us exactly where the GP of the sun is located called HC is 14.9 nautical miles.

You will note that in Celestial One I made a point in suggesting that the dashed line, our Z or azimuth line of 125 degrees should approximate eight inches... "four inches either side of the AP"… Here's why? HOMOTO our formula memory word. Since Ho is more than Hc…than the incept is 14.9 miles toward the GP of the sun.

In our case we therefore measure the distance of 14.9 miles along the azimuth line in the direction of the GP and make a mark. At the mark we construct around a 4 to 6 inch solid line at a right angle or 90 degrees to our dashed azimuth line. This solid line is our LOP that we worked so hard to achieve.

Now I can take my assumed position and my LOP and reference these two applications to my charts DR position and reference its signifance. Remember this is much art as science in determining our actual position. If we happen to obtain another LOP, by whatever means, perhaps another celestial body at a later time, we can advance our 12:15 GMT Sunline that we just plotted and effect what is termed a running fix. "How to do this is explaimed in the accompaning link in the Library also under Diagrams."

One last point, HOMOTO is a very important word in our celestial vocabulary. If in fact Hc was larger than Ho…than the 14.9 intercept mark would be walked off along the dashed line from the assumed position in the direction "away from the arrow head" our LOP constructed of course from that mark... This of course means that if you happened to make this crucial mistake, after all that work you did, your LOP would be almost 30 miles off the LOP's correct position …so be careful.