# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Message:αβγ
Message:abc
 Add Images & Files Posting Code: Name: Email:
Re: Azimuth method for position
From: Bill Lionheart
Date: 2017 Oct 20, 17:49 +0100

```It seems to me that the problem of measuring azimuth at sea is two
fold. First is that even a corrected magnetic compass is only accurate
to about one degree. Second is devising a sufficiently accurate
instrument to measure the difference in azimuth between stars.

If you can solve the second problem you could  devise a least squares
solution to the problem of fitting the difference in azimuths, and
indeed of one star was Polaris this would be more or less the same as
having the absolute azimuth. But to measure the azimuth one still
needs a horizontal reference of some kind. The question then is if you
can get away with a less accurate horizontal reference than needed to
measure altitudes to one minute.

There is a lot more to this problem that just solving the equations
with Newton's method on a computer!

On 20 October 2017 at 15:28, Herman Dekker  wrote:
> Hello Francis,
>
> How does your "specially adapted Az compass " looks like? I have found a
> compass that is usable till about H=60°. Above that height it is a guess
> every time.
>
> Regards,
>
> HermanD
>
> View and reply to this message

--
Professor of Applied Mathematics
University of Manchester
http://www.maths.manchester.ac.uk/bl
```
Browse Files

Drop Files

### Join NavList

 Name: (please, no nicknames or handles) Email:
 Do you want to receive all group messages by email? Yes No
You can also join by posting. Your first on-topic post automatically makes you a member.

### Posting Code

Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
 Email:

### Email Settings

 Posting Code:

### Custom Index

 Subject: Author: Start date: (yyyymm dd) End date: (yyyymm dd)