This Xcos block allows for Lyddane analytical orbit propagation.
Block allows for propagation of Keplerian orbital elements from epoch time to the current time. Lyddane analytical model is used to perform the propagation, therefore zonals coefficients up to J5 are taken into account. Block can accept mean or osculating orbital elements as an input. It has two outputs, providing respectively propagated mean and osculating elements. Classical Keplerian arguments (in order used in block input) are:
sma : semi-major axis [m]
ecc : eccentricity
inc : inclination [rad]
pom : periapsis argument [rad]
raan : right ascension of ascending node [rad]
anm : mean anomaly [m]
This block does not work for inclinations close to the critical inclinations (63.43494882 deg and 116.5650512 deg)
This block does not work for eccentricities higher than 0.9
If any of above conditions is encountered at any point during the simulation it will be stopped and propper error message will appear.
Input 1: 6x1 double (initial keplerian elements)
Input 2: 1x1 double (epoch time in modified julian day since 1950 format)
Input 2: 1x1 double (current time in modified julian day since 1950 format)
Output 1: 6x1 double (propagated mean keplerian elemnts)
Output 2: 6x1 double (propagated osculatng keplerian elemnts)
Orbital elements type (mean/osc) - defines type of the input arguments fed to the block. Mean or osculating Keplerian elements can be used.
Orbital elements type (mean/osc) = mean
macros/LYDDANE_PROPAGATOR.sci
macros/AB_ex_lyddane.sci