Welcome to the NavList Message Boards.

NavList:

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

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Venus mer-pass for Lat, Sun time sight for Lon.
    From: Tony Oz
    Date: 2020 Apr 15, 09:15 -0700

    Dear Antoine,

    I use the older Soviet-era СНО-М which I inspect for perpendicularity/side/index error(s) before every session. It is indeed in good condition, I rarely have to touch those settings. If the IE is in the ±0,2' range - I do not zero it out completely. Very rarely I find it (the IE) just outside that range. I never proceed to taking sights before I do the IE measurement with the Sun's width and the readings also give the correct value for the Sun's SD (taken from the NA).

    The Venus-Sun session we discuss was made with the 7x Keplerian scope. I doubt I could reach that level of accuracy of the sights with a 3x Galilean scope, more so - with a peep-hole (0x scope) accessory. With the latter - I'd never saw Venus in the daylight.

    Regarding the raw data: I thought it would be completely impolite to publish that. I though it would require anyone potentially interested to apply the watch error correction, etc. Besides, just recently we had a topic of the Error vs Correction, and I'm not sure we (the list members) have all agreed on that. As of me - I use a formula which returns a signed value I always (algebraically) add to HS's. So, this must be a "correction" but in my logs I write it under the "IE" name, this will definitely confuse someone. Probably I should just change my habit. By the way, if my watch was fast by 40 seconds, what is the supposed way to mention that? I write that the "WE" (the Watch Error) is "-0h00m40s", the negative value - the same as with the index error.

    Did you get my privately-sent e-mail?

    Warm regards,
    Tony
    60°N 30°E

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    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)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site