A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: John D. Howard
Date: 2016 Dec 28, 08:56 -0800
Thank you for your very thoughtfull reply. You have the atvantage in that you sail and fly.
I have played with cel nav since 1991 but as an avaitor. As I have said many times on this NavList sailors and pilots see the world different.
When I said make a Lambert chart what I was trying to say is that If someone made a small Lambert chart and put it next to a Mercator or a plotting sheet made graphily that no one would see a difference at that small a scale. They would all be comformal.
You talked about my plane graph paper chart and finding your AP and the longitude of the fix. I may have been doing things wrong all these years but I take a UPS or graph paper and draw a X in the middle and that is my AP. The North - South scale is NM ( or tenth of NM ), use a protractor to draw my Azimuth and then draw the LOP so many NM from my AP. Where the LOPs cross I note how many NM north or south and east or west. For north-south I just say that NMs are minutes of arc and add that to my AP. For east-west I multiply by cos(lat) and call the result degrees of arc and add that result to my AP.
Over the years I seem to get accurate results. I do not draw any other mederians on the plotting sheet because I never saw what good they would do. I never thought I was drawing a map ( chart ) and I know I could not use my piece of paper to go anywhere - it only gave me a Lat & Long of my fix.
I have used GPS since the early 1980s but back then they only gave you a lat & long and you needed to plot those onto a map. That is how I use a plotting sheet - to get a lat & long so I can plot them onto my map.
From what I am reading from list members is that sailors use the plotting chart as a map, not just to get a fix.
Gary, thanks again for your reply but you did shatter a long held myth. I have flown from Christchurch to McMurdo so for a few hours in a forty year career I used a ( transverse ) Mercator chart. :-(