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: getting GHA from MICA
    From: Sean C
    Date: 2014 Mar 21, 14:30 -0700

    "My later program, Lunar3, is better for navigation. It's primarily for lunars, but will also compute altitude intercepts." -Paul

    Speaking of lunars, I've been using all of these programs and Frank's web page to check my work after manually (on a calculator) working some lunars. If I understand correctly, the "corner cosines" Frank writes about should be derived from the apparent altitude of the body at the time of observation. I'd like to ask everyone how best to find Ha from Hc. Currently, I'm using Hc & HP to estimate the parallax in altitude, then using trial and error to arrive at the correct value. I do the same for refraction, but this is generally easier since the value's rate of change seems to be slower. I tried thinking of a way of reversing the equations, but since the correction is derived from the value I'm seeking (and I'm no good at math), I can't figure it out. Any help would be greatly appreciated.

    Thanks,
    Sean C.
    ----------------------------------------------------------------
    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com
    ----------------------------------------------------------------

       
    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