Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


singularity in normal equations

singularity in normal equations

singularity in normal equations

  As I am trying to create my own orbit determination program using the least squares differential correction method, I wanted to start with a simple model of a geo synchronous satellite orbiting spherical Earth. Everything went OK, at least as I think, but ended up with a problem that I couldn't solve. It is the singularity of the normal equations. I tried the method of singular value decomposition but that didn't help much. To solve the problem, I tried an initial state vector (nominal) that is almost the same as the vector I used to generate my observations: range, azimuth and elevation. But when I try an initial state vector that is somewhat different, the iterations diverge. Yes, it could be a problem of two faces: 1. the singularity of normal equations and 2. the divergence of iterations.
  I am following the algorithm suggested by many including Vallado, Montenbruck and Tapley, and I am using Matlab on Windows XP.
   My problem deepened by the fact that I am not modeling a complicated case, which, I assume, makes the model clear and simple. This lead me to think if it is a problem of algorithm; I mean, one needs to consider other  formulation or insert certain steps in the algorithm that is not found in books.
  I have many details that I am not mentioning..
  I appreciate much any comment or hint
  Thank you in advance.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close