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 11, 13:26 -0700

    Dear Antoine, huge thanks for your interest in my session log!

    1) Ha is the Apparent Altitude, i.e. the value corrected for the index error and dip of the horizon. Ho is the geocentric altitude - i.e. corrected for the refraction, parallax and semi-diameter. I used the A2 table - the combined Refraction and SD corrections - for the Sun. for Venus I used the "STARS AND PLANETS" column;

    2) yes, those two equal Ha's one minute apart - are NOT typos, as I said earlier, the horizon is rather difficult to see at some certain azimuths, and I thought it could be the mer-pass. One typo is in the Ho: both values should be 55°10,4';

    3) my actual position was 60°10,3'N 29°48,5'E (according to my smartphone's GPS info - I've waited several minutes for it to "settle-in"). The UTs are taken from a Casio with the known watch-error (by listening to the RWM station);

    4) though I used the A4 table for the additional corrections to the refraction for the air-temp and pressure - I'm not sure they are adequate for the actual weather of the date. I suspect it could be for more moderate climates than what we have here|now at 60°N30°E.

    Thank you again! I'm studying your document right now.

    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