The node rate due to the J2 coefficient in Earth's gravitational field is given by

Wj2 = -3*(Req/p)^2*n*J2*cos(i)/2

where the perturbed mean motion is given by

n = sqrt (mu/a^3)*(1+3*J2*(Req/p)^2*(3*(cos(i))^2-1)/(4*sqrt(1-e^2)))

The period of the orbit is given by

T = 2*pi()/n

The angle, Dlong, between successive ascending nodes, measured in the equatorial plane, is given by

Dlong = (-We + Wj2)*T

and the distance along the equator between successive node crossing points is given by

Dist = Dlong*Req

a = r (for circular orbits only)

p = a * (1 - e^2)

r = Req + ALT (altitude at the ascending node point)

.0010826>td>-228.1365

St | Input | Name | Output | Units | Comments | |

6378.16 | Req | km | Equatorial radius of Earth | |||

398598.15 | mu | km^3/s^2 | Earth's gravitational parameter | |||

7.2921E-5 | We | rad/s | Earth's rotation rate | |||

J2 | Oblateness Coefficient | |||||

1.991E-7 | Wj2 | rad/s | Sunsynch Node Rotation due to J2 | |||

L | ALT | km | Altitude | |||

L | a | 6150.0235 | km | Semi-major Axis of Orbit | ||

0 | e | Eccentricity of Orbit | ||||

L | 95 | i | deg | Inclination of Orbit | ||

p | 6150.0235 | km | Orbit | Parameter | ||

L | r | 6150.0235 | km | Radius of Orbit | ||

L | T | 4803.9284 | sec | Period of Orbit | ||

n | .00130793 | sec^-1 | Mean Motion of Orbit | |||

L | Dlong | -20.01639 | deg | Change in Ascending Node per Rev | ||

L | Dist | -2228.222 | km | Distance between successive nodes |

CSR/TSGC Team Web