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: Longhand Sight Reduction
    From: Greg Rudzinski
    Date: 2014 Jun 27, 20:01 -0700

    Hanno,

    The L-d subtraction is trouble. What I do when needed is subtract a degree and then add 60 minutes to the minute value.

    Example:

    42° 3' - 23° 17' is the same as 41° 63' - 23° 17' which can now be done mentally to get 18° 46'

    Division and subtraction is where I need to be careful. Pulling the wrong value out of an almanac or table happens more frequently than it should . 

    Greg Rudzinski

    Re: Longhand Sight Reduction
    From: Hanno Ix
    Date: 2014 Jun 27, 17:04 -0700

    Greg, 
     
    I can see where you are coming from. Of course, though, 
    this is a matter of personal preference.
    I like to do CelNav calculations by hand. I admit I am
    a purist in this regard. Most importantly, it keeps my old brain 
    lubricated. Also, my logic tells me if I used a calculator for CelNav 
    I might as well use one with built-in GPS and be done.
     
    When I analyzed some time ago where I make mistakes most
    often, it was multi-digit multiplications and sexagesimal arithmetic.
    Ridiculous but true: 23 deg 52 min + 14deg 12 min could make me
    insecure about my result. And, horror,  L+D and L- D occurs in Doniol.
     
    For multiplication I use only Vedic anymore. Since I started using
    Vedic and arcmin only I end up with much less errors. 

    Less, I say, not none :(
     
    Hanno
       
    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