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
    Name or NavList Code:
    Email:
       
    Reply
    Re: ephemeris & positional astronomy Windows DLL
    From: Paul Hirose
    Date: 2009 Aug 15, 12:00 -0700

    NavList@fer3.com wrote:
    > I came across this posting, dated almost 3 years ago. I am interested to try 
    out your Astronomy Windows DLL, if you still have it?
    >
    > Appreciate if you can email me the files.
    
    Better yet, you can now download the files yourself from my Web site:
    http://home.earthlink.net/~s543t-24dst/index.html
    
    The DLL in my old message is available there, though it's not maintained
    anymore. The only known bugs are in the SOFA routines FK52H and H2FK5,
    which transform FK5 star catalog data into the Hipparcos system and vice
    versa. My routines do not depend on them, but if you call them directly
    the results may be wrong:
    http://www.iau-sofa.rl.ac.uk/changes_2009_0201.html
    
    A minor problem is that the internal UTC table is out of date. However,
    the DLL has functions to write the table to a file, and load the table
    from a file. This is just a text file, so it can be updated by hand. But
    the updated table will have to be loaded every time you use the DLL. If
    you don't do that, the DLL will revert to its obsolete internal table.
    
    Last year I released a new version of my DLL to run under the Windows
    .NET Framework. It's a vastly superior product. (Strictly speaking it's
    a .NET assembly, not just a DLL.) The old one was heavily biased in
    favor of C programmers as far as the function calling conventions and
    documentation. But with .NET it was possible to make this new release
    independent of language.
    
    One lost feature is the built-in subset of the Hipparcos star catalog. I
    intend to implement a similar feature in a later release. Another change
    is the lack of a default leap second table. That's an intentional
    omission. Sooner or later the table will have to be updated, and I now
    believe it's false kindness to "help" the user with a default table.
    It's better to require explicit loading of a table.
    
    Note that the SOFA routine DAT, which returns TAI-UTC, has its own
    hardwired leap second table and may be called directly. Embedding the
    table into the source code is an arguable design choice, though. It
    requires an edit and recompile of the SOFA code every time a leap second
    is announced. Then that forces me to rebuild my SofaJpl package and
    issue a new installer. Fortunately there will be no leap second at the
    end of this year!
    
    I will be happy to answer any questions about either version of my DLL.
    But contact me at the address I'm using here. The one I give on the Web
    page is not checked daily.
    
    --
    
    
    --~--~---------~--~----~------------~-------~--~----~
    NavList message boards: www.fer3.com/arc
    Or post by email to: NavList@fer3.com
    To , email NavList-@fer3.com
    -~----------~----~----~----~------~----~------~--~---
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

    Enter the email address associated with your NavList messages. Your NavList code will be emailed to you immediately.
    Email:

    Email Settings

    NavList ID 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