Welcome to the NavList Message Boards.


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

Compose Your Message

Add Images & Files
    Re: Location without DR
    From: Frank Reed
    Date: 2018 Feb 21, 08:12 -0800

    Marco, just to emphasize, it is relatively easy to modify your algorithm to generate points in such a manner that they are evenly-distibuted over the globe --evenly-distributed in the sense that the probability per square mile is the same at all latitudes and longitudes. There are a number of ways to do this. I'll repeat my standard approach here since it's short and simple:

    Generate a pair of random numbers (x,y) in the range from -90 to +90. If x>90·cos(y), reject the point.
    Then y is interpreted as latitude and x is converted to longitude:
       Lat = y,
       Lon = 2·x/cos(y).

    That's all there is to it (assuming I set it up correctly!). Now you have random points with no preference for one geographic region over another. 

    Frank Reed

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    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 Settings

    Posting Code:

    Custom Index

    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