{myadvertisements[zone_1]}
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Apparent time
#4
Ive never tried to ascertain longitude or latitude with a noon shot, but I am aware that LAN is not always LAN. The sun, as I recall, is sometimes advanced or retarded of clock noon if I'm thinking about this correctly. The difference between zenith and clock noon is shown in the daily pages as equation of time or Meridian passage.

A plotting chart has a true compass rose and is also marked in degrees of latitude. Draw a line from the center out to your latutude along the circle. Using dividers pick off miles from the meridian (central vertical line), then lay it along the diagonal you drew. Draw a vertical line down to the parallel and thats the equivalent short longitude. Im at 10 degrees north so there is only a slight difference between equatorial and local divisions, but I draw the diagonal every time just so I don't get lazy. I guess this might be termed the graphic method. Works for me.

First thing I do with a plot sheet is draw in my dr bracketing meridians to either side of the circle intersecting the latitudes north and south. Then I draw the diagonal as mentioned which scales minute and second for that latitude. I never use the associated longitude scale.

I hope were all talking about the same thing. Lol

I'd like to know more about meridional parts and how to use them.

BTW - sometimes to assist accuracy I rescale the ups to reflect half degrees both lat and long... it makes the mile tick marks into half mile. With some planning you could even quarter or double the ups. My ups are all 8.5x11. Rescaling saves me the expense of large plotting sheets.

Cheers.
Reply
{myadvertisements[zone_3]}


Messages In This Thread
Apparent time - by Rumata - 02-05-2021, 03:18 AM
RE: Apparent time - by P.Rutherford - 02-05-2021, 02:51 PM
RE: Apparent time - by Rumata - 02-05-2021, 05:07 PM
RE: Apparent time - by pabrides - 02-06-2021, 08:41 AM

Forum Jump:


Users browsing this thread: 1 Guest(s)
{myadvertisements[zone_2]}