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: The Dunlap Sunrise Sunset Computer
    From: Rafal O.
    Date: 2019 Feb 12, 08:36 -0800

    Hello,

        I have found thia post while searching throught the NavList archive. As I like such analog computers, slide rules, ... I decided to make my own version of this sunrise / sunset computer.

        You can see assembled unit in the attached images. Let us check its accuracy: I want to know thr time of sunrise and sunset for November, 15th for 51N and 17E. Equation of time and declination are -15min and 19S, respectively. These values can be read on the back of the computer. Aligning 19S declination with 51N latitude gives me the following UTC times for 0E: 0730 and 1623. After adding EoT: 0715 and 1608. Correction for latitude is -0108 which corresponds to 0607 and 1500 UTC. These correspond to 0707 and 1600 local time. On timeanddate.com I get 0707 and 1603. Errors are 0 for sunrise (clearly very lucky) and -3 for sunset. Quite good for the first try, I think.

    Best wishes,

    Rafal

    File:


    File:


       
    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