Numerical methods for ground simulation of satellite motion
Environmental models applicable for purposes of mission analysis were developed, documented, and recommended. The findings are described.
Bettis, D. G.↗
Engineering topics
Bettis, D. G.
Publications and source records attributed to Bettis, D. G..
Equations of condition for high order Runge-Kutta-Nystrom formulae
Derivation of the equations of condition of order eight for a general system of second-order differential equations approximated by the basic Runge-Kutta-Nystrom algorithm. For this general case, the number of equations of condition is considerably larger than for the special case where the first derivative is not present. Specifically, it is shown that, for orders two through eight, the number of equations for each order is 1, 1, 1, 2, 3, 5, and 9 for the special case and is 1, 1, 2, 5, 13, 34, and 95 for the general case.
Bettis, D. G.↗
A Runge-Kutta Nystrom algorithm.
A Runge-Kutta algorithm of order five is presented for the solution of the initial value problem where the system of ordinary differential equations is of second order and does not contain the first derivative. The algorithm includes the Fehlberg step control procedure.
Bettis, D. G.↗
Numerical integration of products of Fourier and ordinary polynomials
Coefficients for finite difference methods of numerical integration of products of Fourier and ordinary polynomials
Bettis, D. G.↗