Welcome, Guest |
You have to register before you can post on our site.
|
Online Users |
There are currently 25 online users. » 0 Member(s) | 24 Guest(s) Google
|
Latest Threads |
1997 Cassens & Plath Hori...
Forum: General Topics Here
Last Post: ZephyrNYC
Yesterday, 09:59 PM
» Replies: 4
» Views: 94
|
1966 C. Plath, Hamburg se...
Forum: General Topics Here
Last Post: ZephyrNYC
01-06-2025, 08:56 PM
» Replies: 6
» Views: 263
|
Best celnav books availab...
Forum: General Topics Here
Last Post: PeterB
01-04-2025, 04:07 PM
» Replies: 3
» Views: 261
|
Simex Sextant No Optics S...
Forum: General Topics Here
Last Post: PeterB
01-02-2025, 05:26 PM
» Replies: 0
» Views: 59
|
2025- Everything You Need
Forum: 2025- Everything You Need
Last Post: CelNav57
12-16-2024, 02:00 PM
» Replies: 0
» Views: 222
|
Regarding assumed longit...
Forum: The Sight Reduction process
Last Post: Rumata
11-16-2024, 12:32 AM
» Replies: 4
» Views: 842
|
Dastardly Practice Questi...
Forum: General Topics Here
Last Post: Rumata
11-15-2024, 01:46 AM
» Replies: 1
» Views: 376
|
Sight Calc App for Sight ...
Forum: The Sight Reduction process
Last Post: PeterB
11-04-2024, 07:09 PM
» Replies: 1
» Views: 2,265
|
Latitude by Polaris
Forum: General Topics Here
Last Post: PeterB
07-30-2024, 02:49 PM
» Replies: 3
» Views: 1,574
|
Two Moonset times in the ...
Forum: General Topics Here
Last Post: rascalsailor
06-25-2024, 12:48 PM
» Replies: 4
» Views: 2,326
|
|
|
Instructions- Sun sight reduction |
Posted by: CelNav57 - 12-29-2015, 05:26 PM - Forum: The Sight Reduction process
- Replies (1)
|
|
We've just added the procedure for carrying out a Sun sight reduction while using the horizon.
It is thorough with step-by-step instructions and plenty of pictures and examples.
A Sun sight reduction form is included which is used in the described process.
The procedure also includes the plotting of the LOP.
This is perfect for the beginner who is having difficulty understanding how to carry out a Sun sight reduction, what documents are needed, where to get them.
Complete Sun Sight Reduction Procedure
CelNav57
|
|
|
Going blind |
Posted by: Rdutton - 12-26-2015, 01:30 PM - Forum: General Topics Here
- No Replies
|
|
Why is the print so small on both Pub. 249 and HO-229?
All of the print in sextant work is small.
I tell you I'm going blind!!!
Roland
|
|
|
No new sextant |
Posted by: Rdutton - 12-26-2015, 01:14 PM - Forum: General Topics Here
- No Replies
|
|
To my surprise I got no new astro-nav equipment for Christmas.
The Seahorse hardcase I asked for didn't come down the chimney!
Nuts.
|
|
|
shooting a star |
Posted by: stargazer - 12-24-2015, 02:24 AM - Forum: The Sight Reduction process
- Replies (6)
|
|
Here is something I remembered that may or may not be helpful.
When I was about ten years old I purchased a very cheap plastic sextant. I could never understand the "grownup" directions that came with it.
One evening I was standing facing the western horizon trying to aim at the horizon and pick up a star in the mirror. A cool Coast Guard guy came by and told me "Try doing it this way". He had his own "real" sextant that seemed to weigh 100 pounds. He showed me that if I held the sextant upside down and pointed the telescope at the star, it was easy to find the horizon in the mirror, couldn't miss.
OK, maybe everyone knows this, or maybe I remember it wrong, but that is the way I remember it. I'm old now so that was long ago.
For some reason I'm reading about celestial navigation and interested in learning the basics. Finally, after all this time! I've always navigated the mountains and wilderness using stars and moon and sun as a compass for direction only, but especially not for longitude. In the north, Polaris always shows your basic latitude with no tables or books. But longitude is difficult.
How do you all note the time to the second when operating alone? Glance at watch and subtract a second, then read the angle?
|
|
|
Sight reduction- Spreadsheet |
Posted by: LouisC - 12-23-2015, 02:39 PM - Forum: General Topics Here
- No Replies
|
|
I'm lazy and sometimes am not inclined to work with paper-and-pencil so I use this spreadsheet;
Sunsight reduction spreadsheet
I put the program on my cheapy tablet and get Ho, Hc, Zn and Int. fast.
It can be used to determine any needed figures for the Sun.
Such as;
-Sunrise (UTC)
-Sunset
-MP
Very handy.
Lou
|
|
|
Perfect Christmas Book for the Celestial Navigator |
Posted by: jackdale - 12-21-2015, 10:43 PM - Forum: General Topics Here
- Replies (1)
|
|
Sextant - David Barrie
This one line made the whole read worthwhile.
"It is time to rediscover the joys of celestial navigation, not merely as a safety net, but because using a sextant to find our way puts us in the closest possible touch with the natural world at its most sublime. "
We use the universe to find our place in it.
|
|
|
Sun sights during cloudy weather |
Posted by: CarlosPindle - 12-21-2015, 06:47 PM - Forum: The Sight Reduction process
- Replies (1)
|
|
The clouds aren't always cooperative when taking shots of the Sun. The Sun partially peeking through an overcast sky can often be useful when using the correct filter. What I mean is the Sun often appears as though you're viewing it through fog.
How cloudy of a day has it been when you made a successful shot of the Sun?
Is there and infrared detecting sextant?
Carlos
|
|
|
Joshua Slocum- Around the World Alone |
Posted by: Lipr - 12-21-2015, 01:23 PM - Forum: General Topics Here
- Replies (1)
|
|
Slocum was the first solo-circumnavigator and used the Moon as the principle celestial body for observation.
He was a Lunarian. That means he performed "Lunars" which required 2 bodies for site reduction;
1- the moon
2- a star
The reduction was very time consuming.
From my reading Lunars didn't require a highly accurate chronometer and thus his complaint about his 25 cent tin clock and that a watchmaker wanted $1.50 just to rate it.
Here's the story of his trip;
Joshua Slocum- Sailing alone around the World
Larry
|
|
|
|