Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Orbit Determination Issue (Method of Gauss, in Escobal's text)

  1. Aug 13, 2014 #1
    So I'm coding up some initial orbit determination stuff in MATLAB (for personal education; I love this stuff), and I am using 'Methods of Orbit Determination' by Escobal as a guide. I already got Vallado's code to work, now I'm just comparing other methods. I'm having an issue with one of his equations, though. Obviously, the method is angles-only, but one of the givens Escobal requires is H_i, and in his nomenclature section he says that H is the "Altitude of satellite measured normal to adopted ellipsoid". So its the altitude, which is an unknown since we don't have the orbit. I don't even have range data. Am I interpreting this part wrong? The reason I care about that variable is that my values for the X, Y, and Z vectors are off, which gives me a small slatn range value, which gives me the incorrect final value. the set of equations is:
    G1(i) = a_e/sqrt(1-(2*f-f^2)*sin(phi)^2) + H ;
    G2(i) = (1-f)^2*a_e/sqrt(1-(2*f-f^2)*sin(phi)^2) + H ;
    X(i) = -G1(i)*cosd(phi)*cosd(theta(i)) ;
    Y(i) = -G1(i)*cosd(phi)*sind(theta(i)) ;
    Z(i) = -G2(i)*sind(phi) ;

    Any ideas/help would be greatly appreciated.
     
  2. jcsd
  3. Aug 27, 2014 #2
    I'm sorry you are not finding help at the moment. Is there any additional information you can share with us?
     
  4. Oct 16, 2015 #3
    Hi!

    Do you have Vallado's code maybe? I would really like to take a look at it :)
    Thanks!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Orbit Determination Issue (Method of Gauss, in Escobal's text)
  1. Texts for Vibration (Replies: 4)

  2. Kinematic issue (Replies: 0)

  3. Motor issue (Replies: 2)

Loading...