USERS GUIDE, CONSTANTS, AND SYMBOLS

The first input card is the program card. The format is as follows:

verbatim3#

All times are in minutes since epoch and can be positive or negative. The second and third input cards consist of either a 2-card transmission or 2-card G type element set. Either type can be used with the only condition being that the two cards must be in the correct order. For reference a format sheet for the T-card and G-card element sets follows this section.

The values of the physical and mathematical constants used in the program are given below.



Variable name ;SPMnbsp;;SPMnbsp;;SPMnbsp;;SPMnbsp;distance units/Earth radii ;SPMnbsp;;SPMnbsp;;SPMnbsp;;SPMnbsp;
Variable name 		 Definition 		 Value



CK2 		 #math394##tex2html_wrap_inline4798#J₂a_E² 5.413080E-4



CK4 		 #math395#- #tex2html_wrap_inline4802#J₄a_E⁴ .62098875E-6



E6A 		 10^-6 1.0 E-6



QOMS2T 		 #math396#(q_o - s)⁴<#1#> (er)<#1#>⁴ 1.88027916E-9



S 		 #math397#s<#1#> (er)<#1#> 1.01222928



TOTHRD 		 2/3 		 .66666667



XJ3 		 J₃ -.253881E-5



XKE 		 #math398#k_e#tex2html_wrap_inline4810##tex2html_wrap_inline4811##tex2html_wrap_inline4812# .743669161E-1



XKMPER 		 kilometers/Earth radii 		 6378.135



XMNPDA 		 time units/day 		 1440.0



AE 		 distance units/Earth radii 		 1.0



DE2RA 		 radians/degree 		 .174532925E-1



PI 		 π 3.14159265



PIO2 		 π/2 1.57079633



TWOPI 		 2π 6.2831853



X3PIO2 		 3π/2 4.71238898

where er = Earth radii. Except for the deep-space models, all ephemeris models are independent of units. Thus, units input or output as well as physical constants can be changed by making the appropriate changes in only the DRIVER program.

Following is a list of symbols commonly used in this report.

n_o = the SGP type ``mean'' mean motion at epoch

e_o = the ``mean'' eccentricity at epoch

i_o = the ``mean'' inclination at epoch

M_o = the ``mean'' mean anomaly at epoch

ω_o = the ``mean'' argument of perigee at epoch

Ω_o = the ``mean'' longitude of ascending node at epoch

#tex2html_wrap_inline4824# = the time rate of change of ``mean'' mean motion at epoch

#math399##tex2html_wrap_inline4826# = the second time rate of change of ``mean'' mean motion at epoch

B^* = the SGP4 type drag coefficient

k_e = #tex2html_wrap_inline4829#

a_E = the equatorial radius of the Earth

J₂ = the second gravitational zonal harmonic of the Earth

J₃ = the third gravitational zonal harmonic of the Earth

J₄ = the fourth gravitational zonal harmonic of the Earth

(t - t_o) = time since epoch

#math400#k₂ = #tex2html_wrap_inline4836#J₂a_E²

#math401#k₄ = - #tex2html_wrap_inline4840#J₄a_E⁴

#math402#A_{3, 0} = - J₃a_E³

q_o = parameter for the SGP4/SGP8 density function

s = parameter for the SGP4/SGP8 density function

B = #tex2html_wrap_inline4849#